content: /*
   * Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
   * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  
  package java.io;
  
  import java.nio.charset.Charset;
  import java.nio.charset.CharsetEncoder;
  import sun.nio.cs.StreamEncoder;
  
  
  /**
   * An OutputStreamWriter is a bridge from character streams to byte streams:
   * Characters written to it are encoded into bytes using a specified {@link
   * Charset charset}.  The charset that it uses
   * may be specified by name or may be given explicitly, or the platform's
   * default charset may be accepted.
   *
   * <p> Each invocation of a write() method causes the encoding converter to be
   * invoked on the given character(s).  The resulting bytes are accumulated in a
   * buffer before being written to the underlying output stream.  The size of
   * this buffer may be specified, but by default it is large enough for most
   * purposes.  Note that the characters passed to the write() methods are not
   * buffered.
   *
   * <p> For top efficiency, consider wrapping an OutputStreamWriter within a
   * BufferedWriter so as to avoid frequent converter invocations.  For example:
   *
   * <pre>
   * Writer out
   *   = new BufferedWriter(new OutputStreamWriter(System.out));
   * </pre>
   *
   * <p> A <i>surrogate pair</i> is a character represented by a sequence of two
   * <tt>char</tt> values: A <i>high</i> surrogate in the range '&#92;uD800' to
   * '&#92;uDBFF' followed by a <i>low</i> surrogate in the range '&#92;uDC00' to
   * '&#92;uDFFF'.
   *
   * <p> A <i>malformed surrogate element</i> is a high surrogate that is not
   * followed by a low surrogate or a low surrogate that is not preceded by a
   * high surrogate.
   *
   * <p> This class always replaces malformed surrogate elements and unmappable
   * character sequences with the charset's default <i>substitution sequence</i>.
   * The {@linkplain CharsetEncoder} class should be used when more
   * control over the encoding process is required.
   *
   * @see BufferedWriter
   * @see OutputStream
   * @see Charset
   *
   * @author      Mark Reinhold
   * @since       JDK1.1
   */
  
  public class OutputStreamWriter extends Writer {
  
      private final StreamEncoder se;
  
      /**
       * Creates an OutputStreamWriter that uses the named charset.
       *
       * @param  out
       *         An OutputStream
       *
       * @param  charsetName
       *         The name of a supported
       *         {@link Charset charset}
       *
       * @exception  UnsupportedEncodingException
       *             If the named encoding is not supported
       */
      public OutputStreamWriter(OutputStream out, String charsetName)
          throws UnsupportedEncodingException
      {
          super(out);
          if (charsetName == null)
              throw new NullPointerException("charsetName");
          se = StreamEncoder.forOutputStreamWriter(out, this, charsetName);
      }
  
      /**
       * Creates an OutputStreamWriter that uses the default character encoding.
       *
       * @param  out  An OutputStream
       */
      public OutputStreamWriter(OutputStream out) {
          super(out);
          try {
              se = StreamEncoder.forOutputStreamWriter(out, this, (String)null);
          } catch (UnsupportedEncodingException e) {
              throw new Error(e);
          }
      }
  
      /**
       * Creates an OutputStreamWriter that uses the given charset.
       *
       * @param  out
       *         An OutputStream
       *
       * @param  cs
       *         A charset
       *
       * @since 1.4
       * @spec JSR-51
       */
      public OutputStreamWriter(OutputStream out, Charset cs) {
          super(out);
          if (cs == null)
              throw new NullPointerException("charset");
          se = StreamEncoder.forOutputStreamWriter(out, this, cs);
      }
  
      /**
       * Creates an OutputStreamWriter that uses the given charset encoder.
       *
       * @param  out
       *         An OutputStream
       *
       * @param  enc
       *         A charset encoder
       *
       * @since 1.4
       * @spec JSR-51
       */
      public OutputStreamWriter(OutputStream out, CharsetEncoder enc) {
          super(out);
          if (enc == null)
              throw new NullPointerException("charset encoder");
          se = StreamEncoder.forOutputStreamWriter(out, this, enc);
      }
  
      /**
       * Returns the name of the character encoding being used by this stream.
       *
       * <p> If the encoding has an historical name then that name is returned;
       * otherwise the encoding's canonical name is returned.
       *
       * <p> If this instance was created with the {@link
       * #OutputStreamWriter(OutputStream, String)} constructor then the returned
       * name, being unique for the encoding, may differ from the name passed to
       * the constructor.  This method may return <tt>null</tt> if the stream has
       * been closed. </p>
       *
       * @return The historical name of this encoding, or possibly
       *         <code>null</code> if the stream has been closed
       *
       * @see Charset
       *
       * @revised 1.4
       * @spec JSR-51
       */
      public String getEncoding() {
          return se.getEncoding();
      }
  
      /**
       * Flushes the output buffer to the underlying byte stream, without flushing
       * the byte stream itself.  This method is non-private only so that it may
       * be invoked by PrintStream.
       */
      void flushBuffer() throws IOException {
          se.flushBuffer();
      }
  
      /**
       * Writes a single character.
       *
       * @exception  IOException  If an I/O error occurs
       */
      public void write(int c) throws IOException {
          se.write(c);
      }
  
      /**
       * Writes a portion of an array of characters.
       *
       * @param  cbuf  Buffer of characters
       * @param  off   Offset from which to start writing characters
       * @param  len   Number of characters to write
       *
       * @exception  IOException  If an I/O error occurs
       */
      public void write(char cbuf[], int off, int len) throws IOException {
          se.write(cbuf, off, len);
      }
  
      /**
       * Writes a portion of a string.
       *
       * @param  str  A String
       * @param  off  Offset from which to start writing characters
       * @param  len  Number of characters to write
       *
       * @exception  IOException  If an I/O error occurs
       */
      public void write(String str, int off, int len) throws IOException {
          se.write(str, off, len);
      }
  
      /**
       * Flushes the stream.
       *
       * @exception  IOException  If an I/O error occurs
       */
      public void flush() throws IOException {
          se.flush();
      }
  
      public void close() throws IOException {
          se.close();
      }
  }
  