content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   * 
   *      http://www.apache.org/licenses/LICENSE-2.0
   * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
  */
  package tern.utils;
  
  import java.io.BufferedInputStream;
  import java.io.BufferedReader;
  import java.io.ByteArrayInputStream;
  import java.io.CharArrayWriter;
  import java.io.Closeable;
  import java.io.EOFException;
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.io.OutputStream;
  import java.io.OutputStreamWriter;
  import java.io.PrintWriter;
  import java.io.Reader;
  import java.io.Writer;
  import java.net.ServerSocket;
  import java.net.Socket;
  import java.net.URI;
  import java.net.URL;
  import java.nio.channels.Selector;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  
  import tern.internal.org.apache.commons.io.output.ByteArrayOutputStream;
  import tern.internal.org.apache.commons.io.output.StringBuilderWriter;
  
  /**
   * General IO stream manipulation utilities.
   * <p>
   * This class provides static utility methods for input/output operations.
   * <ul>
   * <li>closeQuietly - these methods close a stream ignoring nulls and exceptions
   * <li>toXxx/read - these methods read data from a stream
   * <li>write - these methods write data to a stream
   * <li>copy - these methods copy all the data from one stream to another
   * <li>contentEquals - these methods compare the content of two streams
   * </ul>
   * <p>
   * The byte-to-char methods and char-to-byte methods involve a conversion step.
   * Two methods are provided in each case, one that uses the platform default
   * encoding and the other which allows you to specify an encoding. You are
   * encouraged to always specify an encoding because relying on the platform
   * default can lead to unexpected results, for example when moving from
   * development to production.
   * <p>
   * All the methods in this class that read a stream are buffered internally.
   * This means that there is no cause to use a <code>BufferedInputStream</code>
   * or <code>BufferedReader</code>. The default buffer size of 4K has been shown
   * to be efficient in tests.
   * <p>
   * Wherever possible, the methods in this class do <em>not</em> flush or close
   * the stream. This is to avoid making non-portable assumptions about the
   * streams' origin and further use. Thus the caller is still responsible for
   * closing streams after use.
   * <p>
   * Origin of code: Excalibur.
   *
   * @version $Id: IOUtils.java 1304177 2012-03-23 03:36:44Z ggregory $
   */
  public class IOUtils {
      // NOTE: This class is focussed on InputStream, OutputStream, Reader and
      // Writer. Each method should take at least one of these as a parameter,
      // or return one of them.
  
      private static final int EOF = -1;
      /**
       * The Unix directory separator character.
       */
      public static final char DIR_SEPARATOR_UNIX = '/';
      /**
       * The Windows directory separator character.
       */
      public static final char DIR_SEPARATOR_WINDOWS = '\\';
      /**
       * The system directory separator character.
       */
      public static final char DIR_SEPARATOR = File.separatorChar;
      /**
       * The Unix line separator string.
       */
      public static final String LINE_SEPARATOR_UNIX = "\n";
      /**
       * The Windows line separator string.
       */
      public static final String LINE_SEPARATOR_WINDOWS = "\r\n";
      /**
       * The system line separator string.
       */
      public static final String LINE_SEPARATOR;
      
      static {
          // avoid security issues
          StringBuilderWriter buf = new StringBuilderWriter(4);
          PrintWriter out = new PrintWriter(buf);
          out.println();
          LINE_SEPARATOR = buf.toString();
          out.close();
      }
  
      /**
       * The default buffer size ({@value}) to use for 
       * {@link #copyLarge(InputStream, OutputStream)}
       * and
       * {@link #copyLarge(Reader, Writer)}
       */
      private static final int DEFAULT_BUFFER_SIZE = 1024 * 4;
  
      /**
       * The default buffer size to use for the skip() methods.
       */
      private static final int SKIP_BUFFER_SIZE = 2048;
      
      // Allocated in the relevant skip method if necessary.
      /*
       * N.B. no need to synchronize these because:
       * - we don't care if the buffer is created multiple times (the data is ignored)
       * - we always use the same size buffer, so if it it is recreated it will still be OK
       * (if the buffer size were variable, we would need to synch. to ensure some other thread
       * did not create a smaller one)
       */
      private static char[] SKIP_CHAR_BUFFER;
      private static byte[] SKIP_BYTE_BUFFER;
  
      /**
       * Instances should NOT be constructed in standard programming.
       */
      private IOUtils() {
          super();
      }
  
      //-----------------------------------------------------------------------
      /**
       * Unconditionally close an <code>Reader</code>.
       * <p>
       * Equivalent to {@link Reader#close()}, except any exceptions will be ignored.
       * This is typically used in finally blocks.
       * <p>
       * Example code:
       * <pre>
       *   char[] data = new char[1024];
       *   Reader in = null;
       *   try {
       *       in = new FileReader("foo.txt");
       *       in.read(data);
       *       in.close(); //close errors are handled
       *   } catch (Exception e) {
       *       // error handling
       *   } finally {
       *       IOUtils.closeQuietly(in);
       *   }
       * </pre>
       * 
       * @param input  the Reader to close, may be null or already closed
       */
      public static void closeQuietly(Reader input) {
          closeQuietly((Closeable)input);
      }
  
      /**
       * Unconditionally close a <code>Writer</code>.
       * <p>
       * Equivalent to {@link Writer#close()}, except any exceptions will be ignored.
       * This is typically used in finally blocks.
       * <p>
       * Example code:
       * <pre>
       *   Writer out = null;
       *   try {
       *       out = new StringWriter();
       *       out.write("Hello World");
       *       out.close(); //close errors are handled
       *   } catch (Exception e) {
       *       // error handling
       *   } finally {
       *       IOUtils.closeQuietly(out);
       *   }
       * </pre>
       *
       * @param output  the Writer to close, may be null or already closed
       */
      public static void closeQuietly(Writer output) {
          closeQuietly((Closeable)output);
      }
  
      /**
       * Unconditionally close an <code>InputStream</code>.
       * <p>
       * Equivalent to {@link InputStream#close()}, except any exceptions will be ignored.
       * This is typically used in finally blocks.
       * <p>
       * Example code:
       * <pre>
       *   byte[] data = new byte[1024];
       *   InputStream in = null;
       *   try {
       *       in = new FileInputStream("foo.txt");
       *       in.read(data);
       *       in.close(); //close errors are handled
       *   } catch (Exception e) {
       *       // error handling
       *   } finally {
       *       IOUtils.closeQuietly(in);
       *   }
       * </pre>
       *
       * @param input  the InputStream to close, may be null or already closed
       */
      public static void closeQuietly(InputStream input) {
          closeQuietly((Closeable)input);
      }
  
      /**
       * Unconditionally close an <code>OutputStream</code>.
       * <p>
       * Equivalent to {@link OutputStream#close()}, except any exceptions will be ignored.
       * This is typically used in finally blocks.
       * <p>
       * Example code:
       * <pre>
       * byte[] data = "Hello, World".getBytes();
       *
       * OutputStream out = null;
       * try {
       *     out = new FileOutputStream("foo.txt");
       *     out.write(data);
       *     out.close(); //close errors are handled
       * } catch (IOException e) {
       *     // error handling
       * } finally {
       *     IOUtils.closeQuietly(out);
       * }
       * </pre>
       *
       * @param output  the OutputStream to close, may be null or already closed
       */
      public static void closeQuietly(OutputStream output) {
          closeQuietly((Closeable)output);
      }
      
      /**
       * Unconditionally close a <code>Closeable</code>.
       * <p>
       * Equivalent to {@link Closeable#close()}, except any exceptions will be ignored.
       * This is typically used in finally blocks.
       * <p>
       * Example code:
       * <pre>
       *   Closeable closeable = null;
       *   try {
       *       closeable = new FileReader("foo.txt");
       *       // process closeable
       *       closeable.close();
       *   } catch (Exception e) {
       *       // error handling
       *   } finally {
       *       IOUtils.closeQuietly(closeable);
       *   }
       * </pre>
       *
       * @param closeable the object to close, may be null or already closed
       * @since 2.0
       */
      public static void closeQuietly(Closeable closeable) {
          try {
              if (closeable != null) {
                  closeable.close();
              }
          } catch (IOException ioe) {
              // ignore
          }
      }
  
      /**
       * Unconditionally close a <code>Socket</code>.
       * <p>
       * Equivalent to {@link Socket#close()}, except any exceptions will be ignored.
       * This is typically used in finally blocks.
       * <p>
       * Example code:
       * <pre>
       *   Socket socket = null;
       *   try {
       *       socket = new Socket("http://www.foo.com/", 80);
       *       // process socket
       *       socket.close();
       *   } catch (Exception e) {
       *       // error handling
       *   } finally {
       *       IOUtils.closeQuietly(socket);
       *   }
       * </pre>
       *
       * @param sock the Socket to close, may be null or already closed
       * @since 2.0
       */
      public static void closeQuietly(Socket sock){
          if (sock != null){
              try {
                  sock.close();
              } catch (IOException ioe) {
                  // ignored
              }
          }
      }
  
      /**
       * Unconditionally close a <code>Selector</code>.
       * <p>
       * Equivalent to {@link Selector#close()}, except any exceptions will be ignored.
       * This is typically used in finally blocks.
       * <p>
       * Example code:
       * <pre>
       *   Selector selector = null;
       *   try {
       *       selector = Selector.open();
       *       // process socket
       *       
       *   } catch (Exception e) {
       *       // error handling
       *   } finally {
       *       IOUtils.closeQuietly(selector);
       *   }
       * </pre>
       *
       * @param selector the Selector to close, may be null or already closed
       * @since 2.2
       */
      public static void closeQuietly(Selector selector){
          if (selector != null){
              try {
                selector.close();
              } catch (IOException ioe) {
                  // ignored
              }
          }
      }
      
      /**
       * Unconditionally close a <code>ServerSocket</code>.
       * <p>
       * Equivalent to {@link ServerSocket#close()}, except any exceptions will be ignored.
       * This is typically used in finally blocks.
       * <p>
       * Example code:
       * <pre>
       *   ServerSocket socket = null;
       *   try {
       *       socket = new ServerSocket();
       *       // process socket
       *       socket.close();
       *   } catch (Exception e) {
       *       // error handling
       *   } finally {
       *       IOUtils.closeQuietly(socket);
       *   }
       * </pre>
       *
       * @param sock the ServerSocket to close, may be null or already closed
       * @since 2.2
       */
      public static void closeQuietly(ServerSocket sock){
          if (sock != null){
              try {
                  sock.close();
              } catch (IOException ioe) {
                  // ignored
              }
          }
      }
  
      /**
       * Fetches entire contents of an <code>InputStream</code> and represent
       * same data as result InputStream.
       * <p>
       * This method is useful where,
       * <ul>
       * <li>Source InputStream is slow.</li>
       * <li>It has network resources associated, so we cannot keep it open for
       * long time.</li>
       * <li>It has network timeout associated.</li>
       * </ul>
       * It can be used in favor of {@link #toByteArray(InputStream)}, since it
       * avoids unnecessary allocation and copy of byte[].<br>
       * This method buffers the input internally, so there is no need to use a
       * <code>BufferedInputStream</code>.
       * 
       * @param input Stream to be fully buffered.
       * @return A fully buffered stream.
       * @throws IOException if an I/O error occurs
       * @since 2.0
       */
      public static InputStream toBufferedInputStream(InputStream input) throws IOException {
          return ByteArrayOutputStream.toBufferedInputStream(input);
      }
  
      /**
       * Returns the given reader if it is a {@link BufferedReader}, otherwise creates a toBufferedReader for the given
       * reader.
       * 
       * @param reader
       *            the reader to wrap or return
       * @return the given reader or a new {@link BufferedReader} for the given reader
       * @since 2.2
       */
      public static BufferedReader toBufferedReader(Reader reader) {
          return reader instanceof BufferedReader ? (BufferedReader) reader : new BufferedReader(reader);
      }
      
      // read toByteArray
      //-----------------------------------------------------------------------
      /**
       * Get the contents of an <code>InputStream</code> as a <code>byte[]</code>.
       * <p>
       * This method buffers the input internally, so there is no need to use a
       * <code>BufferedInputStream</code>.
       * 
       * @param input  the <code>InputStream</code> to read from
       * @return the requested byte array
       * @throws NullPointerException if the input is null
       * @throws IOException if an I/O error occurs
       */
      public static byte[] toByteArray(InputStream input) throws IOException {
          ByteArrayOutputStream output = new ByteArrayOutputStream();
          copy(input, output);
          return output.toByteArray();
      }
  
      /**
       * Get contents of an <code>InputStream</code> as a <code>byte[]</code>.
       * Use this method instead of <code>toByteArray(InputStream)</code>
       * when <code>InputStream</code> size is known.
       * <b>NOTE:</b> the method checks that the length can safely be cast to an int without truncation
       * before using {@link IOUtils#toByteArray(java.io.InputStream, int)} to read into the byte array.
       * (Arrays can have no more than Integer.MAX_VALUE entries anyway)
       * 
       * @param input the <code>InputStream</code> to read from
       * @param size the size of <code>InputStream</code>
       * @return the requested byte array
       * @throws IOException if an I/O error occurs or <code>InputStream</code> size differ from parameter size
       * @throws IllegalArgumentException if size is less than zero or size is greater than Integer.MAX_VALUE
       * @see IOUtils#toByteArray(java.io.InputStream, int)
       * @since 2.1
       */
      public static byte[] toByteArray(InputStream input, long size) throws IOException {
  
        if(size > Integer.MAX_VALUE) {
            throw new IllegalArgumentException("Size cannot be greater than Integer max value: " + size);
        }
  
        return toByteArray(input, (int) size);
      }
  
      /** 
       * Get the contents of an <code>InputStream</code> as a <code>byte[]</code>.
       * Use this method instead of <code>toByteArray(InputStream)</code>
       * when <code>InputStream</code> size is known
       * @param input the <code>InputStream</code> to read from
       * @param size the size of <code>InputStream</code>
       * @return the requested byte array
       * @throws IOException if an I/O error occurs or <code>InputStream</code> size differ from parameter size
       * @throws IllegalArgumentException if size is less than zero
       * @since 2.1
       */
      public static byte[] toByteArray(InputStream input, int size) throws IOException {
  
          if (size < 0) {
              throw new IllegalArgumentException("Size must be equal or greater than zero: " + size);
          }
  
          if (size == 0) {
              return new byte[0];
          }
  
          byte[] data = new byte[size];
          int offset = 0;
          int readed;
  
          while (offset < size && (readed = input.read(data, offset, size - offset)) != EOF) {
              offset += readed;
          }
  
          if (offset != size) {
              throw new IOException("Unexpected readed size. current: " + offset + ", excepted: " + size);
          }
  
          return data;
      }
  
      /**
       * Get the contents of a <code>Reader</code> as a <code>byte[]</code>
       * using the default character encoding of the platform.
       * <p>
       * This method buffers the input internally, so there is no need to use a
       * <code>BufferedReader</code>.
       * 
       * @param input  the <code>Reader</code> to read from
       * @return the requested byte array
       * @throws NullPointerException if the input is null
       * @throws IOException if an I/O error occurs
       */
      public static byte[] toByteArray(Reader input) throws IOException {
          ByteArrayOutputStream output = new ByteArrayOutputStream();
          copy(input, output);
          return output.toByteArray();
      }
  
      /**
       * Get the contents of a <code>Reader</code> as a <code>byte[]</code>
       * using the specified character encoding.
       * <p>
       * Character encoding names can be found at
       * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
       * <p>
       * This method buffers the input internally, so there is no need to use a
       * <code>BufferedReader</code>.
       * 
       * @param input  the <code>Reader</code> to read from
       * @param encoding  the encoding to use, null means platform default
       * @return the requested byte array
       * @throws NullPointerException if the input is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static byte[] toByteArray(Reader input, String encoding)
              throws IOException {
          ByteArrayOutputStream output = new ByteArrayOutputStream();
          copy(input, output, encoding);
          return output.toByteArray();
      }
  
      /**
       * Get the contents of a <code>String</code> as a <code>byte[]</code>
       * using the default character encoding of the platform.
       * <p>
       * This is the same as {@link String#getBytes()}.
       * 
       * @param input  the <code>String</code> to convert
       * @return the requested byte array
       * @throws NullPointerException if the input is null
       * @throws IOException if an I/O error occurs (never occurs)
       * @deprecated Use {@link String#getBytes()}
       */
      @Deprecated
      public static byte[] toByteArray(String input) throws IOException {
          return input.getBytes();
      }
  
      // read char[]
      //-----------------------------------------------------------------------
      /**
       * Get the contents of an <code>InputStream</code> as a character array
       * using the default character encoding of the platform.
       * <p>
       * This method buffers the input internally, so there is no need to use a
       * <code>BufferedInputStream</code>.
       * 
       * @param is  the <code>InputStream</code> to read from
       * @return the requested character array
       * @throws NullPointerException if the input is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static char[] toCharArray(InputStream is) throws IOException {
          CharArrayWriter output = new CharArrayWriter();
          copy(is, output);
          return output.toCharArray();
      }
  
      /**
       * Get the contents of an <code>InputStream</code> as a character array
       * using the specified character encoding.
       * <p>
       * Character encoding names can be found at
       * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
       * <p>
       * This method buffers the input internally, so there is no need to use a
       * <code>BufferedInputStream</code>.
       * 
       * @param is  the <code>InputStream</code> to read from
       * @param encoding  the encoding to use, null means platform default
       * @return the requested character array
       * @throws NullPointerException if the input is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static char[] toCharArray(InputStream is, String encoding)
              throws IOException {
          CharArrayWriter output = new CharArrayWriter();
          copy(is, output, encoding);
          return output.toCharArray();
      }
  
      /**
       * Get the contents of a <code>Reader</code> as a character array.
       * <p>
       * This method buffers the input internally, so there is no need to use a
       * <code>BufferedReader</code>.
       * 
       * @param input  the <code>Reader</code> to read from
       * @return the requested character array
       * @throws NullPointerException if the input is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static char[] toCharArray(Reader input) throws IOException {
          CharArrayWriter sw = new CharArrayWriter();
          copy(input, sw);
          return sw.toCharArray();
      }
  
      // read toString
      //-----------------------------------------------------------------------
      /**
       * Get the contents of an <code>InputStream</code> as a String
       * using the default character encoding of the platform.
       * <p>
       * This method buffers the input internally, so there is no need to use a
       * <code>BufferedInputStream</code>.
       * 
       * @param input  the <code>InputStream</code> to read from
       * @return the requested String
       * @throws NullPointerException if the input is null
       * @throws IOException if an I/O error occurs
       */
      public static String toString(InputStream input) throws IOException {
          return toString(input, null);
      }
  
      /**
       * Get the contents of an <code>InputStream</code> as a String
       * using the specified character encoding.
       * <p>
       * Character encoding names can be found at
       * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
       * <p>
       * This method buffers the input internally, so there is no need to use a
       * <code>BufferedInputStream</code>.
       * 
       * @param input  the <code>InputStream</code> to read from
       * @param encoding  the encoding to use, null means platform default
       * @return the requested String
       * @throws NullPointerException if the input is null
       * @throws IOException if an I/O error occurs
       */
      public static String toString(InputStream input, String encoding)
              throws IOException {
          StringBuilderWriter sw = new StringBuilderWriter();
          copy(input, sw, encoding);
          return sw.toString();
      }
  
      /**
       * Get the contents of a <code>Reader</code> as a String.
       * <p>
       * This method buffers the input internally, so there is no need to use a
       * <code>BufferedReader</code>.
       * 
       * @param input  the <code>Reader</code> to read from
       * @return the requested String
       * @throws NullPointerException if the input is null
       * @throws IOException if an I/O error occurs
       */
      public static String toString(Reader input) throws IOException {
          StringBuilderWriter sw = new StringBuilderWriter();
          copy(input, sw);
          return sw.toString();
      }
  
      /**
       * Gets the contents at the given URI.
       * 
       * @param uri
       *            The URI source.
       * @return The contents of the URL as a String.
       * @throws IOException if an I/O exception occurs.
       * @since 2.1.
       */
      public static String toString(URI uri) throws IOException {
          return toString(uri, null);
      }
  
      /**
       * Gets the contents at the given URI.
       * 
       * @param uri
       *            The URI source.
       * @param encoding
       *            The encoding name for the URL contents.
       * @return The contents of the URL as a String.
       * @throws IOException if an I/O exception occurs.
       * @since 2.1.
       */
      public static String toString(URI uri, String encoding) throws IOException {
          return toString(uri.toURL(), encoding);
      }
  
      /**
       * Gets the contents at the given URL.
       * 
       * @param url
       *            The URL source.
       * @return The contents of the URL as a String.
       * @throws IOException if an I/O exception occurs.
       * @since 2.1.
       */
      public static String toString(URL url) throws IOException {
          return toString(url, null);
      }
  
      /**
       * Gets the contents at the given URL.
       * 
       * @param url
       *            The URL source.
       * @param encoding
       *            The encoding name for the URL contents.
       * @return The contents of the URL as a String.
       * @throws IOException if an I/O exception occurs.
       * @since 2.1.
       */
      public static String toString(URL url, String encoding) throws IOException {
          InputStream inputStream = url.openStream();
          try {
              return toString(inputStream, encoding);
          } finally {
              inputStream.close();
          }
      }
  
      /**
       * Get the contents of a <code>byte[]</code> as a String
       * using the default character encoding of the platform.
       * 
       * @param input the byte array to read from
       * @return the requested String
       * @throws NullPointerException if the input is null
       * @throws IOException if an I/O error occurs (never occurs)
       * @deprecated Use {@link String#String(byte[])}
       */
      @Deprecated
      public static String toString(byte[] input) throws IOException {
          return new String(input);
      }
  
      /**
       * Get the contents of a <code>byte[]</code> as a String
       * using the specified character encoding.
       * <p>
       * Character encoding names can be found at
       * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
       * 
       * @param input the byte array to read from
       * @param encoding  the encoding to use, null means platform default
       * @return the requested String
       * @throws NullPointerException if the input is null
       * @throws IOException if an I/O error occurs (never occurs)
       * @deprecated Use {@link String#String(byte[],String)}
       */
      @Deprecated
      public static String toString(byte[] input, String encoding)
              throws IOException {
          if (encoding == null) {
              return new String(input);
          } else {
              return new String(input, encoding);
          }
      }
  
      // readLines
      //-----------------------------------------------------------------------
      /**
       * Get the contents of an <code>InputStream</code> as a list of Strings,
       * one entry per line, using the default character encoding of the platform.
       * <p>
       * This method buffers the input internally, so there is no need to use a
       * <code>BufferedInputStream</code>.
       *
       * @param input  the <code>InputStream</code> to read from, not null
       * @return the list of Strings, never null
       * @throws NullPointerException if the input is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static List<String> readLines(InputStream input) throws IOException {
          InputStreamReader reader = new InputStreamReader(input);
          return readLines(reader);
      }
  
      /**
       * Get the contents of an <code>InputStream</code> as a list of Strings,
       * one entry per line, using the specified character encoding.
       * <p>
       * Character encoding names can be found at
       * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
       * <p>
       * This method buffers the input internally, so there is no need to use a
       * <code>BufferedInputStream</code>.
       *
       * @param input  the <code>InputStream</code> to read from, not null
       * @param encoding  the encoding to use, null means platform default
       * @return the list of Strings, never null
       * @throws NullPointerException if the input is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static List<String> readLines(InputStream input, String encoding) throws IOException {
          if (encoding == null) {
              return readLines(input);
          } else {
              InputStreamReader reader = new InputStreamReader(input, encoding);
              return readLines(reader);
          }
      }
  
      /**
       * Get the contents of a <code>Reader</code> as a list of Strings,
       * one entry per line.
       * <p>
       * This method buffers the input internally, so there is no need to use a
       * <code>BufferedReader</code>.
       *
       * @param input  the <code>Reader</code> to read from, not null
       * @return the list of Strings, never null
       * @throws NullPointerException if the input is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static List<String> readLines(Reader input) throws IOException {
          BufferedReader reader = toBufferedReader(input);
          List<String> list = new ArrayList<String>();
          String line = reader.readLine();
          while (line != null) {
              list.add(line);
              line = reader.readLine();
          }
          return list;
      }
  
      // lineIterator
      //-----------------------------------------------------------------------
      /**
       * Return an Iterator for the lines in a <code>Reader</code>.
       * <p>
       * <code>LineIterator</code> holds a reference to the open
       * <code>Reader</code> specified here. When you have finished with the
       * iterator you should close the reader to free internal resources.
       * This can be done by closing the reader directly, or by calling
       * {@link LineIterator#close()} or {@link LineIterator#closeQuietly(LineIterator)}.
       * <p>
       * The recommended usage pattern is:
       * <pre>
       * try {
       *   LineIterator it = IOUtils.lineIterator(reader);
       *   while (it.hasNext()) {
       *     String line = it.nextLine();
       *     /// do something with line
       *   }
       * } finally {
       *   IOUtils.closeQuietly(reader);
       * }
       * </pre>
       *
       * @param reader  the <code>Reader</code> to read from, not null
       * @return an Iterator of the lines in the reader, never null
       * @throws IllegalArgumentException if the reader is null
       * @since 1.2
       */
      /*public static LineIterator lineIterator(Reader reader) {
          return new LineIterator(reader);
      }*/
  
      /**
       * Return an Iterator for the lines in an <code>InputStream</code>, using
       * the character encoding specified (or default encoding if null).
       * <p>
       * <code>LineIterator</code> holds a reference to the open
       * <code>InputStream</code> specified here. When you have finished with
       * the iterator you should close the stream to free internal resources.
       * This can be done by closing the stream directly, or by calling
       * {@link LineIterator#close()} or {@link LineIterator#closeQuietly(LineIterator)}.
       * <p>
       * The recommended usage pattern is:
       * <pre>
       * try {
       *   LineIterator it = IOUtils.lineIterator(stream, "UTF-8");
       *   while (it.hasNext()) {
       *     String line = it.nextLine();
       *     /// do something with line
       *   }
       * } finally {
       *   IOUtils.closeQuietly(stream);
       * }
       * </pre>
       *
       * @param input  the <code>InputStream</code> to read from, not null
       * @param encoding  the encoding to use, null means platform default
       * @return an Iterator of the lines in the reader, never null
       * @throws IllegalArgumentException if the input is null
       * @throws IOException if an I/O error occurs, such as if the encoding is invalid
       * @since 1.2
       */
      /*public static LineIterator lineIterator(InputStream input, String encoding) 
                       throws IOException {
          Reader reader = null;
          if (encoding == null) {
              reader = new InputStreamReader(input);
          } else {
              reader = new InputStreamReader(input, encoding);
          }
          return new LineIterator(reader);
      }*/
  
      //-----------------------------------------------------------------------
      /**
       * Convert the specified CharSequence to an input stream, encoded as bytes
       * using the default character encoding of the platform.
       *
       * @param input the CharSequence to convert
       * @return an input stream
       * @since 2.0
       */
      public static InputStream toInputStream(CharSequence input) {
          return toInputStream(input.toString());
      }
  
      /**
       * Convert the specified CharSequence to an input stream, encoded as bytes
       * using the specified character encoding.
       * <p>
       * Character encoding names can be found at
       * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
       *
       * @param input the CharSequence to convert
       * @param encoding the encoding to use, null means platform default
       * @throws IOException if the encoding is invalid
       * @return an input stream
       * @since 2.0
       */
      public static InputStream toInputStream(CharSequence input, String encoding) throws IOException {
          return toInputStream(input.toString(), encoding);
      }
  
      //-----------------------------------------------------------------------
      /**
       * Convert the specified string to an input stream, encoded as bytes
       * using the default character encoding of the platform.
       *
       * @param input the string to convert
       * @return an input stream
       * @since 1.1
       */
      public static InputStream toInputStream(String input) {
          byte[] bytes = input.getBytes();
          return new ByteArrayInputStream(bytes);
      }
  
      /**
       * Convert the specified string to an input stream, encoded as bytes
       * using the specified character encoding.
       * <p>
       * Character encoding names can be found at
       * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
       *
       * @param input the string to convert
       * @param encoding the encoding to use, null means platform default
       * @throws IOException if the encoding is invalid
       * @return an input stream
       * @since 1.1
       */
      public static InputStream toInputStream(String input, String encoding) throws IOException {
          byte[] bytes = encoding != null ? input.getBytes(encoding) : input.getBytes();
          return new ByteArrayInputStream(bytes);
      }
  
      // write byte[]
      //-----------------------------------------------------------------------
      /**
       * Writes bytes from a <code>byte[]</code> to an <code>OutputStream</code>.
       * 
       * @param data  the byte array to write, do not modify during output,
       * null ignored
       * @param output  the <code>OutputStream</code> to write to
       * @throws NullPointerException if output is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static void write(byte[] data, OutputStream output)
              throws IOException {
          if (data != null) {
              output.write(data);
          }
      }
  
      /**
       * Writes bytes from a <code>byte[]</code> to chars on a <code>Writer</code>
       * using the default character encoding of the platform.
       * <p>
       * This method uses {@link String#String(byte[])}.
       * 
       * @param data  the byte array to write, do not modify during output,
       * null ignored
       * @param output  the <code>Writer</code> to write to
       * @throws NullPointerException if output is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static void write(byte[] data, Writer output) throws IOException {
          if (data != null) {
              output.write(new String(data));
          }
      }
  
      /**
       * Writes bytes from a <code>byte[]</code> to chars on a <code>Writer</code>
       * using the specified character encoding.
       * <p>
       * Character encoding names can be found at
       * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
       * <p>
       * This method uses {@link String#String(byte[], String)}.
       * 
       * @param data  the byte array to write, do not modify during output,
       * null ignored
       * @param output  the <code>Writer</code> to write to
       * @param encoding  the encoding to use, null means platform default
       * @throws NullPointerException if output is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static void write(byte[] data, Writer output, String encoding)
              throws IOException {
          if (data != null) {
              if (encoding == null) {
                  write(data, output);
              } else {
                  output.write(new String(data, encoding));
              }
          }
      }
  
      // write char[]
      //-----------------------------------------------------------------------
      /**
       * Writes chars from a <code>char[]</code> to a <code>Writer</code>
       * using the default character encoding of the platform.
       * 
       * @param data  the char array to write, do not modify during output,
       * null ignored
       * @param output  the <code>Writer</code> to write to
       * @throws NullPointerException if output is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static void write(char[] data, Writer output) throws IOException {
          if (data != null) {
              output.write(data);
          }
      }
  
      /**
       * Writes chars from a <code>char[]</code> to bytes on an
       * <code>OutputStream</code>.
       * <p>
       * This method uses {@link String#String(char[])} and
       * {@link String#getBytes()}.
       * 
       * @param data  the char array to write, do not modify during output,
       * null ignored
       * @param output  the <code>OutputStream</code> to write to
       * @throws NullPointerException if output is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static void write(char[] data, OutputStream output)
              throws IOException {
          if (data != null) {
              output.write(new String(data).getBytes());
          }
      }
  
      /**
       * Writes chars from a <code>char[]</code> to bytes on an
       * <code>OutputStream</code> using the specified character encoding.
       * <p>
       * Character encoding names can be found at
       * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
       * <p>
       * This method uses {@link String#String(char[])} and
       * {@link String#getBytes(String)}.
       * 
       * @param data  the char array to write, do not modify during output,
       * null ignored
       * @param output  the <code>OutputStream</code> to write to
       * @param encoding  the encoding to use, null means platform default
       * @throws NullPointerException if output is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static void write(char[] data, OutputStream output, String encoding)
              throws IOException {
          if (data != null) {
              if (encoding == null) {
                  write(data, output);
              } else {
                  output.write(new String(data).getBytes(encoding));
              }
          }
      }
  
      // write CharSequence
      //-----------------------------------------------------------------------
      /**
       * Writes chars from a <code>CharSequence</code> to a <code>Writer</code>.
       * 
       * @param data  the <code>CharSequence</code> to write, null ignored
       * @param output  the <code>Writer</code> to write to
       * @throws NullPointerException if output is null
       * @throws IOException if an I/O error occurs
       * @since 2.0
       */
      public static void write(CharSequence data, Writer output) throws IOException {
          if (data != null) {
              write(data.toString(), output);
          }
      }
  
      /**
       * Writes chars from a <code>CharSequence</code> to bytes on an
       * <code>OutputStream</code> using the default character encoding of the
       * platform.
       * <p>
       * This method uses {@link String#getBytes()}.
       * 
       * @param data  the <code>CharSequence</code> to write, null ignored
       * @param output  the <code>OutputStream</code> to write to
       * @throws NullPointerException if output is null
       * @throws IOException if an I/O error occurs
       * @since 2.0
       */
      public static void write(CharSequence data, OutputStream output)
              throws IOException {
          if (data != null) {
              write(data.toString(), output);
          }
      }
  
      /**
       * Writes chars from a <code>CharSequence</code> to bytes on an
       * <code>OutputStream</code> using the specified character encoding.
       * <p>
       * Character encoding names can be found at
       * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
       * <p>
       * This method uses {@link String#getBytes(String)}.
       * 
       * @param data  the <code>CharSequence</code> to write, null ignored
       * @param output  the <code>OutputStream</code> to write to
       * @param encoding  the encoding to use, null means platform default
       * @throws NullPointerException if output is null
       * @throws IOException if an I/O error occurs
       * @since 2.0
       */
      public static void write(CharSequence data, OutputStream output, String encoding)
              throws IOException {
          if (data != null) {
              write(data.toString(), output, encoding);
          }
      }
  
      // write String
      //-----------------------------------------------------------------------
      /**
       * Writes chars from a <code>String</code> to a <code>Writer</code>.
       * 
       * @param data  the <code>String</code> to write, null ignored
       * @param output  the <code>Writer</code> to write to
       * @throws NullPointerException if output is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static void write(String data, Writer output) throws IOException {
          if (data != null) {
              output.write(data);
          }
      }
  
      /**
       * Writes chars from a <code>String</code> to bytes on an
       * <code>OutputStream</code> using the default character encoding of the
       * platform.
       * <p>
       * This method uses {@link String#getBytes()}.
       * 
       * @param data  the <code>String</code> to write, null ignored
       * @param output  the <code>OutputStream</code> to write to
       * @throws NullPointerException if output is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static void write(String data, OutputStream output)
              throws IOException {
          if (data != null) {
              output.write(data.getBytes());
          }
      }
  
      /**
       * Writes chars from a <code>String</code> to bytes on an
       * <code>OutputStream</code> using the specified character encoding.
       * <p>
       * Character encoding names can be found at
       * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
       * <p>
       * This method uses {@link String#getBytes(String)}.
       * 
       * @param data  the <code>String</code> to write, null ignored
       * @param output  the <code>OutputStream</code> to write to
       * @param encoding  the encoding to use, null means platform default
       * @throws NullPointerException if output is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static void write(String data, OutputStream output, String encoding)
              throws IOException {
          if (data != null) {
              if (encoding == null) {
                  write(data, output);
              } else {
                  output.write(data.getBytes(encoding));
              }
          }
      }
  
      // write StringBuffer
      //-----------------------------------------------------------------------
      /**
       * Writes chars from a <code>StringBuffer</code> to a <code>Writer</code>.
       * 
       * @param data  the <code>StringBuffer</code> to write, null ignored
       * @param output  the <code>Writer</code> to write to
       * @throws NullPointerException if output is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       * @deprecated replaced by write(CharSequence, Writer)
       */
      @Deprecated
      public static void write(StringBuffer data, Writer output)
              throws IOException {
          if (data != null) {
              output.write(data.toString());
          }
      }
  
      /**
       * Writes chars from a <code>StringBuffer</code> to bytes on an
       * <code>OutputStream</code> using the default character encoding of the
       * platform.
       * <p>
       * This method uses {@link String#getBytes()}.
       * 
       * @param data  the <code>StringBuffer</code> to write, null ignored
       * @param output  the <code>OutputStream</code> to write to
       * @throws NullPointerException if output is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       * @deprecated replaced by write(CharSequence, OutputStream)
       */
      @Deprecated
      public static void write(StringBuffer data, OutputStream output)
              throws IOException {
          if (data != null) {
              output.write(data.toString().getBytes());
          }
      }
  
      /**
       * Writes chars from a <code>StringBuffer</code> to bytes on an
       * <code>OutputStream</code> using the specified character encoding.
       * <p>
       * Character encoding names can be found at
       * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
       * <p>
       * This method uses {@link String#getBytes(String)}.
       * 
       * @param data  the <code>StringBuffer</code> to write, null ignored
       * @param output  the <code>OutputStream</code> to write to
       * @param encoding  the encoding to use, null means platform default
       * @throws NullPointerException if output is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       * @deprecated replaced by write(CharSequence, OutputStream, String)
       */
      @Deprecated
      public static void write(StringBuffer data, OutputStream output,
              String encoding) throws IOException {
          if (data != null) {
              if (encoding == null) {
                  write(data, output);
              } else {
                  output.write(data.toString().getBytes(encoding));
              }
          }
      }
  
      // writeLines
      //-----------------------------------------------------------------------
      /**
       * Writes the <code>toString()</code> value of each item in a collection to
       * an <code>OutputStream</code> line by line, using the default character
       * encoding of the platform and the specified line ending.
       *
       * @param lines  the lines to write, null entries produce blank lines
       * @param lineEnding  the line separator to use, null is system default
       * @param output  the <code>OutputStream</code> to write to, not null, not closed
       * @throws NullPointerException if the output is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static void writeLines(Collection<?> lines, String lineEnding,
              OutputStream output) throws IOException {
          if (lines == null) {
              return;
          }
          if (lineEnding == null) {
              lineEnding = LINE_SEPARATOR;
          }
          for (Object line : lines) {
              if (line != null) {
                  output.write(line.toString().getBytes());
              }
              output.write(lineEnding.getBytes());
          }
      }
  
      /**
       * Writes the <code>toString()</code> value of each item in a collection to
       * an <code>OutputStream</code> line by line, using the specified character
       * encoding and the specified line ending.
       * <p>
       * Character encoding names can be found at
       * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
       *
       * @param lines  the lines to write, null entries produce blank lines
       * @param lineEnding  the line separator to use, null is system default
       * @param output  the <code>OutputStream</code> to write to, not null, not closed
       * @param encoding  the encoding to use, null means platform default
       * @throws NullPointerException if the output is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static void writeLines(Collection<?> lines, String lineEnding,
              OutputStream output, String encoding) throws IOException {
          if (encoding == null) {
              writeLines(lines, lineEnding, output);
          } else {
              if (lines == null) {
                  return;
              }
              if (lineEnding == null) {
                  lineEnding = LINE_SEPARATOR;
              }
              for (Object line : lines) {
                  if (line != null) {
                      output.write(line.toString().getBytes(encoding));
                  }
                  output.write(lineEnding.getBytes(encoding));
              }
          }
      }
  
      /**
       * Writes the <code>toString()</code> value of each item in a collection to
       * a <code>Writer</code> line by line, using the specified line ending.
       *
       * @param lines  the lines to write, null entries produce blank lines
       * @param lineEnding  the line separator to use, null is system default
       * @param writer  the <code>Writer</code> to write to, not null, not closed
       * @throws NullPointerException if the input is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static void writeLines(Collection<?> lines, String lineEnding,
              Writer writer) throws IOException {
          if (lines == null) {
              return;
          }
          if (lineEnding == null) {
              lineEnding = LINE_SEPARATOR;
          }
          for (Object line : lines) {
              if (line != null) {
                  writer.write(line.toString());
              }
              writer.write(lineEnding);
          }
      }
  
      // copy from File
      //-----------------------------------------------------------------------
  	/**
  	 * Copy bytes from one <code>File</code> to another <code>File</code>.
  	 * Directory files are copied recursively.
  	 * <p>
  	 * Large files (over 2GB) will return a bytes copied value of
  	 * <code>-1</code> after the copy has completed since the correct number of
  	 * bytes cannot be returned as an int. For large files use the
  	 * <code>copyLarge(InputStream, OutputStream)</code> method.
  	 * 
  	 * @param input
  	 *            the <code>File</code> to read from
  	 * @param output
  	 *            the <code>File</code> to write to
  	 * @param forceOverwrite
  	 *            pass <code>true</code> to force existing files to be
  	 *            overwritten regardless; otherwise, a file will only be
  	 *            overwritten if it is older than the file being copied.
  	 * @return the number of bytes copied, or -1 if &gt; Integer.MAX_VALUE
  	 * @throws NullPointerException
  	 *             if the input or output is null
  	 * @throws IOException
  	 *             if an I/O error occurs
  	 * @since 1.1
  	 */
  	public static int copy(File input, File output, boolean forceOverwrite) throws IOException {
  		long count = copyLarge(input, output, forceOverwrite);
  		if (count > Integer.MAX_VALUE) {
  			return -1;
  		}
  		return (int) count;
  	}
  
      // copy from InputStream
      //-----------------------------------------------------------------------
      /**
       * Copy bytes from an <code>InputStream</code> to an
       * <code>OutputStream</code>.
       * <p>
       * This method buffers the input internally, so there is no need to use a
       * <code>BufferedInputStream</code>.
       * <p>
       * Large streams (over 2GB) will return a bytes copied value of
       * <code>-1</code> after the copy has completed since the correct
       * number of bytes cannot be returned as an int. For large streams
       * use the <code>copyLarge(InputStream, OutputStream)</code> method.
       * 
       * @param input  the <code>InputStream</code> to read from
       * @param output  the <code>OutputStream</code> to write to
       * @return the number of bytes copied, or -1 if &gt; Integer.MAX_VALUE
       * @throws NullPointerException if the input or output is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static int copy(InputStream input, OutputStream output) throws IOException {
          long count = copyLarge(input, output);
          if (count > Integer.MAX_VALUE) {
              return -1;
          }
          return (int) count;
      }
  
  	/**
  	 * Copy bytes from one large (over 2GB) <code>File</code> to another
  	 * <code>File</code>. Directory files are copied recursively.
  	 * <p>
  	 * This method buffers the input internally, so there is no need to use a
  	 * <code>BufferedInputStream</code>.
  	 * <p>
  	 * The buffer size is given by {@link #DEFAULT_BUFFER_SIZE}.
  	 * 
  	 * @param input
  	 *            the <code>File</code> to read from
  	 * @param output
  	 *            the <code>File</code> to write to
  	 * @param forceOverwrite
  	 *            pass <code>true</code> to force existing files to be
  	 *            overwritten regardless; otherwise, a file will only be
  	 *            overwritten if it is older than the file being copied.
  	 * @return the number of bytes copied
  	 * @throws NullPointerException
  	 *             if the input or output is null
  	 * @throws IOException
  	 *             if an I/O error occurs
  	 * @since 1.3
  	 */
  	public static long copyLarge(File input, File output, boolean forceOverwrite) throws IOException {
  		if (input.isDirectory()) {
  			if (!output.exists())
  				output.mkdirs();
  			else if (!output.isDirectory())
  				throw new IOException(output.getCanonicalPath() + " already exists but is not a directory");
  			long count = 0L;
  			for (File child : input.listFiles()) {
  				count += copyLarge(child, new File(output, child.getName()), forceOverwrite);
  			}
  			return count;
  		} else if (input.lastModified() > output.lastModified() || forceOverwrite) {
  			if (!output.getParentFile().exists())
  				output.getParentFile().mkdirs();
  			FileInputStream inStream = new FileInputStream(input);
  			FileOutputStream outStream = new FileOutputStream(output);
  			try {
  				return copyLarge(inStream, outStream);
  			} finally {
  				closeQuietly(inStream);
  				closeQuietly(outStream);
  			}
  		} else {
  			return input.length();
  		}
  	}
  
      /**
       * Copy bytes from a large (over 2GB) <code>InputStream</code> to an
       * <code>OutputStream</code>.
       * <p>
       * This method buffers the input internally, so there is no need to use a
       * <code>BufferedInputStream</code>.
       * <p>
       * The buffer size is given by {@link #DEFAULT_BUFFER_SIZE}.
       * 
       * @param input  the <code>InputStream</code> to read from
       * @param output  the <code>OutputStream</code> to write to
       * @return the number of bytes copied
       * @throws NullPointerException if the input or output is null
       * @throws IOException if an I/O error occurs
       * @since 1.3
       */
      public static long copyLarge(InputStream input, OutputStream output)
              throws IOException {
          return copyLarge(input, output, new byte[DEFAULT_BUFFER_SIZE]);
      }
  
      /**
       * Copy bytes from a large (over 2GB) <code>InputStream</code> to an
       * <code>OutputStream</code>.
       * <p>
       * This method uses the provided buffer, so there is no need to use a
       * <code>BufferedInputStream</code>.
       * <p>
       * 
       * @param input  the <code>InputStream</code> to read from
       * @param output  the <code>OutputStream</code> to write to
       * @param buffer the buffer to use for the copy
       * @return the number of bytes copied
       * @throws NullPointerException if the input or output is null
       * @throws IOException if an I/O error occurs
       * @since 2.2
       */
      public static long copyLarge(InputStream input, OutputStream output, byte[] buffer)
              throws IOException {
          long count = 0;
          int n = 0;
          while (EOF != (n = input.read(buffer))) {
              output.write(buffer, 0, n);
              count += n;
          }
          return count;
      }
  
      /**
       * Copy some or all bytes from a large (over 2GB) <code>InputStream</code> to an
       * <code>OutputStream</code>, optionally skipping input bytes.
       * <p>
       * This method buffers the input internally, so there is no need to use a
       * <code>BufferedInputStream</code>.
       * <p>
       * The buffer size is given by {@link #DEFAULT_BUFFER_SIZE}.
       * 
       * @param input  the <code>InputStream</code> to read from
       * @param output  the <code>OutputStream</code> to write to
       * @param inputOffset : number of bytes to skip from input before copying
       *         -ve values are ignored
       * @param length : number of bytes to copy. -ve means all
       * @return the number of bytes copied
       * @throws NullPointerException if the input or output is null
       * @throws IOException if an I/O error occurs
       * @since 2.2
       */
      public static long copyLarge(InputStream input, OutputStream output, long inputOffset, long length)
              throws IOException {
          return copyLarge(input, output, inputOffset, length, new byte[DEFAULT_BUFFER_SIZE]);
      }
  
      /**
       * Copy some or all bytes from a large (over 2GB) <code>InputStream</code> to an
       * <code>OutputStream</code>, optionally skipping input bytes.
       * <p>
       * This method uses the provided buffer, so there is no need to use a
       * <code>BufferedInputStream</code>.
       * <p>
       * 
       * @param input  the <code>InputStream</code> to read from
       * @param output  the <code>OutputStream</code> to write to
       * @param inputOffset : number of bytes to skip from input before copying
       *         -ve values are ignored
       * @param length : number of bytes to copy. -ve means all
       * @param buffer the buffer to use for the copy
       *
       * @return the number of bytes copied
       * @throws NullPointerException if the input or output is null
       * @throws IOException if an I/O error occurs
       * @since 2.2
       */
      public static long copyLarge(InputStream input, OutputStream output, 
              final long inputOffset, final long length, byte[] buffer)  throws IOException {
          if (inputOffset > 0) {
              skipFully(input, inputOffset);
          }
          if (length == 0) {
              return 0;
          }
          final int bufferLength = buffer.length;
          int bytesToRead = bufferLength;
          if (length > 0 && length < bufferLength) {
              bytesToRead = (int) length;
          }
          int read;
          long totalRead = 0;
          while (bytesToRead > 0 && EOF != (read = input.read(buffer, 0, bytesToRead))) {
              output.write(buffer, 0, read);
              totalRead += read;
              if (length > 0) { // only adjust length if not reading to the end
                  // Note the cast must work because buffer.length is an integer
                  bytesToRead = (int) Math.min(length - totalRead, bufferLength);
              }
          }
          return totalRead;
      }
  
      /**
       * Copy bytes from an <code>InputStream</code> to chars on a
       * <code>Writer</code> using the default character encoding of the platform.
       * <p>
       * This method buffers the input internally, so there is no need to use a
       * <code>BufferedInputStream</code>.
       * <p>
       * This method uses {@link InputStreamReader}.
       *
       * @param input  the <code>InputStream</code> to read from
       * @param output  the <code>Writer</code> to write to
       * @throws NullPointerException if the input or output is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static void copy(InputStream input, Writer output)
              throws IOException {
          InputStreamReader in = new InputStreamReader(input);
          copy(in, output);
      }
  
      /**
       * Copy bytes from an <code>InputStream</code> to chars on a
       * <code>Writer</code> using the specified character encoding.
       * <p>
       * This method buffers the input internally, so there is no need to use a
       * <code>BufferedInputStream</code>.
       * <p>
       * Character encoding names can be found at
       * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
       * <p>
       * This method uses {@link InputStreamReader}.
       *
       * @param input  the <code>InputStream</code> to read from
       * @param output  the <code>Writer</code> to write to
       * @param encoding  the encoding to use, null means platform default
       * @throws NullPointerException if the input or output is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static void copy(InputStream input, Writer output, String encoding)
              throws IOException {
          if (encoding == null) {
              copy(input, output);
          } else {
              InputStreamReader in = new InputStreamReader(input, encoding);
              copy(in, output);
          }
      }
  
      // copy from Reader
      //-----------------------------------------------------------------------
      /**
       * Copy chars from a <code>Reader</code> to a <code>Writer</code>.
       * <p>
       * This method buffers the input internally, so there is no need to use a
       * <code>BufferedReader</code>.
       * <p>
       * Large streams (over 2GB) will return a chars copied value of
       * <code>-1</code> after the copy has completed since the correct
       * number of chars cannot be returned as an int. For large streams
       * use the <code>copyLarge(Reader, Writer)</code> method.
       *
       * @param input  the <code>Reader</code> to read from
       * @param output  the <code>Writer</code> to write to
       * @return the number of characters copied, or -1 if &gt; Integer.MAX_VALUE
       * @throws NullPointerException if the input or output is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static int copy(Reader input, Writer output) throws IOException {
          long count = copyLarge(input, output);
          if (count > Integer.MAX_VALUE) {
              return -1;
          }
          return (int) count;
      }
  
      /**
       * Copy chars from a large (over 2GB) <code>Reader</code> to a <code>Writer</code>.
       * <p>
       * This method buffers the input internally, so there is no need to use a
       * <code>BufferedReader</code>.
       * <p>
       * The buffer size is given by {@link #DEFAULT_BUFFER_SIZE}.
       *
       * @param input  the <code>Reader</code> to read from
       * @param output  the <code>Writer</code> to write to
       * @return the number of characters copied
       * @throws NullPointerException if the input or output is null
       * @throws IOException if an I/O error occurs
       * @since 1.3
       */
      public static long copyLarge(Reader input, Writer output) throws IOException {
          return copyLarge(input, output, new char[DEFAULT_BUFFER_SIZE]);
      }
  
      /**
       * Copy chars from a large (over 2GB) <code>Reader</code> to a <code>Writer</code>.
       * <p>
       * This method uses the provided buffer, so there is no need to use a
       * <code>BufferedReader</code>.
       * <p>
       *
       * @param input  the <code>Reader</code> to read from
       * @param output  the <code>Writer</code> to write to
       * @param buffer the buffer to be used for the copy
       * @return the number of characters copied
       * @throws NullPointerException if the input or output is null
       * @throws IOException if an I/O error occurs
       * @since 2.2
       */
      public static long copyLarge(Reader input, Writer output, char [] buffer) throws IOException {
          long count = 0;
          int n = 0;
          while (EOF != (n = input.read(buffer))) {
              output.write(buffer, 0, n);
              count += n;
          }
          return count;
      }
  
      /**
       * Copy some or all chars from a large (over 2GB) <code>InputStream</code> to an
       * <code>OutputStream</code>, optionally skipping input chars.
       * <p>
       * This method buffers the input internally, so there is no need to use a
       * <code>BufferedReader</code>.
       * <p>
       * The buffer size is given by {@link #DEFAULT_BUFFER_SIZE}.
       * 
       * @param input  the <code>Reader</code> to read from
       * @param output  the <code>Writer</code> to write to
       * @param inputOffset : number of chars to skip from input before copying
       *         -ve values are ignored
       * @param length : number of chars to copy. -ve means all
       * @return the number of chars copied
       * @throws NullPointerException if the input or output is null
       * @throws IOException if an I/O error occurs
       * @since 2.2
       */
      public static long copyLarge(Reader input, Writer output, final long inputOffset, final long length)
              throws IOException {
          return  copyLarge(input, output, inputOffset, length, new char[DEFAULT_BUFFER_SIZE]);
      }
  
      /**
       * Copy some or all chars from a large (over 2GB) <code>InputStream</code> to an
       * <code>OutputStream</code>, optionally skipping input chars.
       * <p>
       * This method uses the provided buffer, so there is no need to use a
       * <code>BufferedReader</code>.
       * <p>
       * 
       * @param input  the <code>Reader</code> to read from
       * @param output  the <code>Writer</code> to write to
       * @param inputOffset : number of chars to skip from input before copying
       *         -ve values are ignored
       * @param length : number of chars to copy. -ve means all
       * @param buffer the buffer to be used for the copy
       * @return the number of chars copied
       * @throws NullPointerException if the input or output is null
       * @throws IOException if an I/O error occurs
       * @since 2.2
       */
      public static long copyLarge(Reader input, Writer output, final long inputOffset, final long length, char [] buffer)
              throws IOException {
          if (inputOffset > 0) {
              skipFully(input, inputOffset);
          }
          if (length == 0) {
              return 0;
          }
          int bytesToRead = buffer.length;
          if (length > 0 && length < buffer.length) {
              bytesToRead = (int) length;
          }
          int read;
          long totalRead = 0;
          while (bytesToRead > 0 && EOF != (read = input.read(buffer, 0, bytesToRead))) {
              output.write(buffer, 0, read);
              totalRead += read;
              if (length > 0) { // only adjust length if not reading to the end
                  // Note the cast must work because buffer.length is an integer
                  bytesToRead = (int) Math.min(length - totalRead, buffer.length);
              }
          }
          return totalRead;
      }
  
      /**
       * Copy chars from a <code>Reader</code> to bytes on an
       * <code>OutputStream</code> using the default character encoding of the
       * platform, and calling flush.
       * <p>
       * This method buffers the input internally, so there is no need to use a
       * <code>BufferedReader</code>.
       * <p>
       * Due to the implementation of OutputStreamWriter, this method performs a
       * flush.
       * <p>
       * This method uses {@link OutputStreamWriter}.
       *
       * @param input  the <code>Reader</code> to read from
       * @param output  the <code>OutputStream</code> to write to
       * @throws NullPointerException if the input or output is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static void copy(Reader input, OutputStream output)
              throws IOException {
          OutputStreamWriter out = new OutputStreamWriter(output);
          copy(input, out);
          // XXX Unless anyone is planning on rewriting OutputStreamWriter, we
          // have to flush here.
          out.flush();
      }
  
      /**
       * Copy chars from a <code>Reader</code> to bytes on an
       * <code>OutputStream</code> using the specified character encoding, and
       * calling flush.
       * <p>
       * This method buffers the input internally, so there is no need to use a
       * <code>BufferedReader</code>.
       * <p>
       * Character encoding names can be found at
       * <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
       * <p>
       * Due to the implementation of OutputStreamWriter, this method performs a
       * flush.
       * <p>
       * This method uses {@link OutputStreamWriter}.
       *
       * @param input  the <code>Reader</code> to read from
       * @param output  the <code>OutputStream</code> to write to
       * @param encoding  the encoding to use, null means platform default
       * @throws NullPointerException if the input or output is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static void copy(Reader input, OutputStream output, String encoding)
              throws IOException {
          if (encoding == null) {
              copy(input, output);
          } else {
              OutputStreamWriter out = new OutputStreamWriter(output, encoding);
              copy(input, out);
              // XXX Unless anyone is planning on rewriting OutputStreamWriter,
              // we have to flush here.
              out.flush();
          }
      }
  
      // content equals
      //-----------------------------------------------------------------------
      /**
       * Compare the contents of two Streams to determine if they are equal or
       * not.
       * <p>
       * This method buffers the input internally using
       * <code>BufferedInputStream</code> if they are not already buffered.
       *
       * @param input1  the first stream
       * @param input2  the second stream
       * @return true if the content of the streams are equal or they both don't
       * exist, false otherwise
       * @throws NullPointerException if either input is null
       * @throws IOException if an I/O error occurs
       */
      public static boolean contentEquals(InputStream input1, InputStream input2)
              throws IOException {
          if (!(input1 instanceof BufferedInputStream)) {
              input1 = new BufferedInputStream(input1);
          }
          if (!(input2 instanceof BufferedInputStream)) {
              input2 = new BufferedInputStream(input2);
          }
  
          int ch = input1.read();
          while (EOF != ch) {
              int ch2 = input2.read();
              if (ch != ch2) {
                  return false;
              }
              ch = input1.read();
          }
  
          int ch2 = input2.read();
          return ch2 == EOF;
      }
  
      /**
       * Compare the contents of two Readers to determine if they are equal or
       * not.
       * <p>
       * This method buffers the input internally using
       * <code>BufferedReader</code> if they are not already buffered.
       *
       * @param input1  the first reader
       * @param input2  the second reader
       * @return true if the content of the readers are equal or they both don't
       * exist, false otherwise
       * @throws NullPointerException if either input is null
       * @throws IOException if an I/O error occurs
       * @since 1.1
       */
      public static boolean contentEquals(Reader input1, Reader input2)
              throws IOException {
          
          input1 = toBufferedReader(input1);
          input2 = toBufferedReader(input2);
  
          int ch = input1.read();
          while (EOF != ch) {
              int ch2 = input2.read();
              if (ch != ch2) {
                  return false;
              }
              ch = input1.read();
          }
  
          int ch2 = input2.read();
          return ch2 == EOF;
      }
  
      /**
       * Compare the contents of two Readers to determine if they are equal or
       * not, ignoring EOL characters.
       * <p>
       * This method buffers the input internally using
       * <code>BufferedReader</code> if they are not already buffered.
       *
       * @param input1  the first reader
       * @param input2  the second reader
       * @return true if the content of the readers are equal (ignoring EOL differences),  false otherwise
       * @throws NullPointerException if either input is null
       * @throws IOException if an I/O error occurs
       * @since 2.2
       */
      public static boolean contentEqualsIgnoreEOL(Reader input1, Reader input2)
              throws IOException {
          BufferedReader br1 = toBufferedReader(input1);
          BufferedReader br2 = toBufferedReader(input2);
  
          String line1 = br1.readLine();
          String line2 = br2.readLine();
          while (line1 != null && line2 != null && line1.equals(line2)) {
              line1 = br1.readLine();
              line2 = br2.readLine();
          }
          return line1 == null ? line2 == null ? true : false : line1.equals(line2);
      }
  
      /**
       * Skip bytes from an input byte stream.
       * This implementation guarantees that it will read as many bytes
       * as possible before giving up; this may not always be the case for
       * subclasses of {@link Reader}.
       *   
       * @param input byte stream to skip
       * @param toSkip number of bytes to skip.
       * @return number of bytes actually skipped.
       * 
       * @see InputStream#skip(long)
       * 
       * @throws IOException if there is a problem reading the file
       * @throws IllegalArgumentException if toSkip is negative
       * @since 2.0
       */
      public static long skip(InputStream input, long toSkip) throws IOException {
          if (toSkip < 0) {
              throw new IllegalArgumentException("Skip count must be non-negative, actual: " + toSkip);
          }
          /*
           * N.B. no need to synchronize this because: - we don't care if the buffer is created multiple times (the data
           * is ignored) - we always use the same size buffer, so if it it is recreated it will still be OK (if the buffer
           * size were variable, we would need to synch. to ensure some other thread did not create a smaller one)
           */
          if (SKIP_BYTE_BUFFER == null) {
              SKIP_BYTE_BUFFER = new byte[SKIP_BUFFER_SIZE];
          }
          long remain = toSkip;
          while (remain > 0) {
              long n = input.read(SKIP_BYTE_BUFFER, 0, (int) Math.min(remain, SKIP_BUFFER_SIZE));
              if (n < 0) { // EOF
                  break;
              }
              remain -= n;
          }
          return toSkip - remain;
      }
  
      /**
       * Skip characters from an input character stream.
       * This implementation guarantees that it will read as many characters
       * as possible before giving up; this may not always be the case for
       * subclasses of {@link Reader}.
       *   
       * @param input character stream to skip
       * @param toSkip number of characters to skip.
       * @return number of characters actually skipped.
       * 
       * @see Reader#skip(long)
       * 
       * @throws IOException if there is a problem reading the file
       * @throws IllegalArgumentException if toSkip is negative
       * @since 2.0
       */
      public static long skip(Reader input, long toSkip) throws IOException {
          if (toSkip < 0) {
              throw new IllegalArgumentException("Skip count must be non-negative, actual: " + toSkip);
          }
          /*
           * N.B. no need to synchronize this because: - we don't care if the buffer is created multiple times (the data
           * is ignored) - we always use the same size buffer, so if it it is recreated it will still be OK (if the buffer
           * size were variable, we would need to synch. to ensure some other thread did not create a smaller one)
           */
          if (SKIP_CHAR_BUFFER == null) {
              SKIP_CHAR_BUFFER = new char[SKIP_BUFFER_SIZE];
          }
          long remain = toSkip;
          while (remain > 0) {
              long n = input.read(SKIP_CHAR_BUFFER, 0, (int) Math.min(remain, SKIP_BUFFER_SIZE));
              if (n < 0) { // EOF
                  break;
              }
              remain -= n;
          }
          return toSkip - remain;
      }
  
      /**
       * Skip the requested number of bytes or fail if there are not enough left.
       * <p>
       * This allows for the possibility that {@link InputStream#skip(long)} may
       * not skip as many bytes as requested (most likely because of reaching EOF).
       * 
       * @param input stream to skip
       * @param toSkip the number of bytes to skip
       * @see InputStream#skip(long)
       * 
       * @throws IOException if there is a problem reading the file
       * @throws IllegalArgumentException if toSkip is negative
       * @throws EOFException if the number of bytes skipped was incorrect 
       * @since 2.0
       */
      public static void skipFully(InputStream input, long toSkip) throws IOException {
          if (toSkip < 0) {
              throw new IllegalArgumentException("Bytes to skip must not be negative: " + toSkip);
          }
          long skipped = skip(input, toSkip);
          if (skipped != toSkip) {
              throw new EOFException("Bytes to skip: " + toSkip + " actual: " + skipped);
          }
      }
  
      /**
       * Skip the requested number of characters or fail if there are not enough left.
       * <p>
       * This allows for the possibility that {@link Reader#skip(long)} may
       * not skip as many characters as requested (most likely because of reaching EOF).
       * 
       * @param input stream to skip
       * @param toSkip the number of characters to skip
       * @see Reader#skip(long)
       * 
       * @throws IOException if there is a problem reading the file
       * @throws IllegalArgumentException if toSkip is negative
       * @throws EOFException if the number of characters skipped was incorrect
       * @since 2.0
       */
      public static void skipFully(Reader input, long toSkip) throws IOException {
          long skipped = skip(input, toSkip);
          if (skipped != toSkip) {
              throw new EOFException("Chars to skip: " + toSkip + " actual: " + skipped);
          }
      }
      
  
      /**
       * Read characters from an input character stream.
       * This implementation guarantees that it will read as many characters
       * as possible before giving up; this may not always be the case for
       * subclasses of {@link Reader}.
       * 
       * @param input where to read input from
       * @param buffer destination
       * @param offset inital offset into buffer
       * @param length length to read, must be >= 0
       * @return actual length read; may be less than requested if EOF was reached
       * @throws IOException if a read error occurs
       * @since 2.2
       */
      public static int read(Reader input, char[] buffer, int offset, int length) throws IOException {
          if (length < 0) {
              throw new IllegalArgumentException("Length must not be negative: " + length);
          }
          int remaining = length;
          while (remaining > 0) {
              int location = length - remaining;
              int count = input.read(buffer, offset + location, remaining);
              if (EOF == count) { // EOF
                  break;
              }
              remaining -= count;
          }
          return length - remaining;
      }
  
      /**
       * Read characters from an input character stream.
       * This implementation guarantees that it will read as many characters
       * as possible before giving up; this may not always be the case for
       * subclasses of {@link Reader}.
       * 
       * @param input where to read input from
       * @param buffer destination
       * @return actual length read; may be less than requested if EOF was reached
       * @throws IOException if a read error occurs
       * @since 2.2
       */
      public static int read(Reader input, char[] buffer) throws IOException {
          return read(input, buffer, 0, buffer.length);
      }
  
      /**
       * Read bytes from an input stream.
       * This implementation guarantees that it will read as many bytes
       * as possible before giving up; this may not always be the case for
       * subclasses of {@link InputStream}.
       * 
       * @param input where to read input from
       * @param buffer destination
       * @param offset inital offset into buffer
       * @param length length to read, must be >= 0
       * @return actual length read; may be less than requested if EOF was reached
       * @throws IOException if a read error occurs
       * @since 2.2
       */
      public static int read(InputStream input, byte[] buffer, int offset, int length) throws IOException {
          if (length < 0) {
              throw new IllegalArgumentException("Length must not be negative: " + length);
          }
          int remaining = length;
          while (remaining > 0) {
              int location = length - remaining;
              int count = input.read(buffer, offset + location, remaining);
              if (EOF == count) { // EOF
                  break;
              }
              remaining -= count;
          }
          return length - remaining;
      }
      
      /**
       * Read bytes from an input stream.
       * This implementation guarantees that it will read as many bytes
       * as possible before giving up; this may not always be the case for
       * subclasses of {@link InputStream}.
       * 
       * @param input where to read input from
       * @param buffer destination
       * @return actual length read; may be less than requested if EOF was reached
       * @throws IOException if a read error occurs
       * @since 2.2
       */
      public static int read(InputStream input, byte[] buffer) throws IOException {
          return read(input, buffer, 0, buffer.length);
      }
  
      /**
       * Read the requested number of characters or fail if there are not enough left.
       * <p>
       * This allows for the possibility that {@link Reader#read(char[], int, int)} may
       * not read as many characters as requested (most likely because of reaching EOF).
       * 
       * @param input where to read input from
       * @param buffer destination
       * @param offset inital offset into buffer
       * @param length length to read, must be >= 0
       * 
       * @throws IOException if there is a problem reading the file
       * @throws IllegalArgumentException if length is negative
       * @throws EOFException if the number of characters read was incorrect
       * @since 2.2
       */
      public static void readFully(Reader input, char[] buffer, int offset, int length) throws IOException {
          int actual = read(input, buffer, offset, length);
          if (actual != length) {
              throw new EOFException("Length to read: " + length + " actual: " + actual);
          }
      }
  
      /**
       * Read the requested number of characters or fail if there are not enough left.
       * <p>
       * This allows for the possibility that {@link Reader#read(char[], int, int)} may
       * not read as many characters as requested (most likely because of reaching EOF).
       * 
       * @param input where to read input from
       * @param buffer destination
       * 
       * @throws IOException if there is a problem reading the file
       * @throws IllegalArgumentException if length is negative
       * @throws EOFException if the number of characters read was incorrect
       * @since 2.2
       */
      public static void readFully(Reader input, char[] buffer) throws IOException {
          readFully(input, buffer, 0, buffer.length);
      }
  
      /**
       * Read the requested number of bytes or fail if there are not enough left.
       * <p>
       * This allows for the possibility that {@link InputStream#read(byte[], int, int)} may
       * not read as many bytes as requested (most likely because of reaching EOF).
       * 
       * @param input where to read input from
       * @param buffer destination
       * @param offset inital offset into buffer
       * @param length length to read, must be >= 0
       * 
       * @throws IOException if there is a problem reading the file
       * @throws IllegalArgumentException if length is negative
       * @throws EOFException if the number of bytes read was incorrect
       * @since 2.2
       */
      public static void readFully(InputStream input, byte[] buffer, int offset, int length) throws IOException {
          int actual = read(input, buffer, offset, length);
          if (actual != length) {
              throw new EOFException("Length to read: " + length + " actual: " + actual);
          }
      }
  
      /**
       * Read the requested number of bytes or fail if there are not enough left.
       * <p>
       * This allows for the possibility that {@link InputStream#read(byte[], int, int)} may
       * not read as many bytes as requested (most likely because of reaching EOF).
       * 
       * @param input where to read input from
       * @param buffer destination
       * 
       * @throws IOException if there is a problem reading the file
       * @throws IllegalArgumentException if length is negative
       * @throws EOFException if the number of bytes read was incorrect
       * @since 2.2
       */
      public static void readFully(InputStream input, byte[] buffer) throws IOException {
          readFully(input, buffer, 0, buffer.length);
      }
  }
  