content: /*
   * Copyright (c) 1996, 2004, 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;
  
  
  /**
   * A character stream that collects its output in a string buffer, which can
   * then be used to construct a string.
   * <p>
   * Closing a <tt>StringWriter</tt> has no effect. The methods in this class
   * can be called after the stream has been closed without generating an
   * <tt>IOException</tt>.
   *
   * @author      Mark Reinhold
   * @since       JDK1.1
   */
  
  public class StringWriter extends Writer {
  
      private StringBuffer buf;
  
      /**
       * Create a new string writer using the default initial string-buffer
       * size.
       */
      public StringWriter() {
          buf = new StringBuffer();
          lock = buf;
      }
  
      /**
       * Create a new string writer using the specified initial string-buffer
       * size.
       *
       * @param initialSize
       *        The number of <tt>char</tt> values that will fit into this buffer
       *        before it is automatically expanded
       *
       * @throws IllegalArgumentException
       *         If <tt>initialSize</tt> is negative
       */
      public StringWriter(int initialSize) {
          if (initialSize < 0) {
              throw new IllegalArgumentException("Negative buffer size");
          }
          buf = new StringBuffer(initialSize);
          lock = buf;
      }
  
      /**
       * Write a single character.
       */
      public void write(int c) {
          buf.append((char) c);
      }
  
      /**
       * Write a portion of an array of characters.
       *
       * @param  cbuf  Array of characters
       * @param  off   Offset from which to start writing characters
       * @param  len   Number of characters to write
       */
      public void write(char cbuf[], int off, int len) {
          if ((off < 0) || (off > cbuf.length) || (len < 0) ||
              ((off + len) > cbuf.length) || ((off + len) < 0)) {
              throw new IndexOutOfBoundsException();
          } else if (len == 0) {
              return;
          }
          buf.append(cbuf, off, len);
      }
  
      /**
       * Write a string.
       */
      public void write(String str) {
          buf.append(str);
      }
  
      /**
       * Write a portion of a string.
       *
       * @param  str  String to be written
       * @param  off  Offset from which to start writing characters
       * @param  len  Number of characters to write
       */
      public void write(String str, int off, int len)  {
          buf.append(str.substring(off, off + len));
      }
  
      /**
       * Appends the specified character sequence to this writer.
       *
       * <p> An invocation of this method of the form <tt>out.append(csq)</tt>
       * behaves in exactly the same way as the invocation
       *
       * <pre>
       *     out.write(csq.toString()) </pre>
       *
       * <p> Depending on the specification of <tt>toString</tt> for the
       * character sequence <tt>csq</tt>, the entire sequence may not be
       * appended. For instance, invoking the <tt>toString</tt> method of a
       * character buffer will return a subsequence whose content depends upon
       * the buffer's position and limit.
       *
       * @param  csq
       *         The character sequence to append.  If <tt>csq</tt> is
       *         <tt>null</tt>, then the four characters <tt>"null"</tt> are
       *         appended to this writer.
       *
       * @return  This writer
       *
       * @since  1.5
       */
      public StringWriter append(CharSequence csq) {
          if (csq == null)
              write("null");
          else
              write(csq.toString());
          return this;
      }
  
      /**
       * Appends a subsequence of the specified character sequence to this writer.
       *
       * <p> An invocation of this method of the form <tt>out.append(csq, start,
       * end)</tt> when <tt>csq</tt> is not <tt>null</tt>, behaves in
       * exactly the same way as the invocation
       *
       * <pre>
       *     out.write(csq.subSequence(start, end).toString()) </pre>
       *
       * @param  csq
       *         The character sequence from which a subsequence will be
       *         appended.  If <tt>csq</tt> is <tt>null</tt>, then characters
       *         will be appended as if <tt>csq</tt> contained the four
       *         characters <tt>"null"</tt>.
       *
       * @param  start
       *         The index of the first character in the subsequence
       *
       * @param  end
       *         The index of the character following the last character in the
       *         subsequence
       *
       * @return  This writer
       *
       * @throws  IndexOutOfBoundsException
       *          If <tt>start</tt> or <tt>end</tt> are negative, <tt>start</tt>
       *          is greater than <tt>end</tt>, or <tt>end</tt> is greater than
       *          <tt>csq.length()</tt>
       *
       * @since  1.5
       */
      public StringWriter append(CharSequence csq, int start, int end) {
          CharSequence cs = (csq == null ? "null" : csq);
          write(cs.subSequence(start, end).toString());
          return this;
      }
  
      /**
       * Appends the specified character to this writer.
       *
       * <p> An invocation of this method of the form <tt>out.append(c)</tt>
       * behaves in exactly the same way as the invocation
       *
       * <pre>
       *     out.write(c) </pre>
       *
       * @param  c
       *         The 16-bit character to append
       *
       * @return  This writer
       *
       * @since 1.5
       */
      public StringWriter append(char c) {
          write(c);
          return this;
      }
  
      /**
       * Return the buffer's current value as a string.
       */
      public String toString() {
          return buf.toString();
      }
  
      /**
       * Return the string buffer itself.
       *
       * @return StringBuffer holding the current buffer value.
       */
      public StringBuffer getBuffer() {
          return buf;
      }
  
      /**
       * Flush the stream.
       */
      public void flush() {
      }
  
      /**
       * Closing a <tt>StringWriter</tt> has no effect. The methods in this
       * class can be called after the stream has been closed without generating
       * an <tt>IOException</tt>.
       */
      public void close() throws IOException {
      }
  
  }
  