content: /*
   * Copyright (c) 2003, 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.lang;
  
  import java.io.IOException;
  
  /**
   * An object to which <tt>char</tt> sequences and values can be appended.  The
   * <tt>Appendable</tt> interface must be implemented by any class whose
   * instances are intended to receive formatted output from a {@link
   * java.util.Formatter}.
   *
   * <p> The characters to be appended should be valid Unicode characters as
   * described in <a href="Character.html#unicode">Unicode Character
   * Representation</a>.  Note that supplementary characters may be composed of
   * multiple 16-bit <tt>char</tt> values.
   *
   * <p> Appendables are not necessarily safe for multithreaded access.  Thread
   * safety is the responsibility of classes that extend and implement this
   * interface.
   *
   * <p> Since this interface may be implemented by existing classes
   * with different styles of error handling there is no guarantee that
   * errors will be propagated to the invoker.
   *
   * @since 1.5
   */
  public interface Appendable {
  
      /**
       * Appends the specified character sequence to this <tt>Appendable</tt>.
       *
       * <p> Depending on which class implements the character sequence
       * <tt>csq</tt>, the entire sequence may not be appended.  For
       * instance, if <tt>csq</tt> is a {@link java.nio.CharBuffer} then
       * the subsequence to append is defined by 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 Appendable.
       *
       * @return  A reference to this <tt>Appendable</tt>
       *
       * @throws  IOException
       *          If an I/O error occurs
       */
      Appendable append(CharSequence csq) throws IOException;
  
      /**
       * Appends a subsequence of the specified character sequence to this
       * <tt>Appendable</tt>.
       *
       * <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.append(csq.subSequence(start, end)) </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  A reference to this <tt>Appendable</tt>
       *
       * @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>
       *
       * @throws  IOException
       *          If an I/O error occurs
       */
      Appendable append(CharSequence csq, int start, int end) throws IOException;
  
      /**
       * Appends the specified character to this <tt>Appendable</tt>.
       *
       * @param  c
       *         The character to append
       *
       * @return  A reference to this <tt>Appendable</tt>
       *
       * @throws  IOException
       *          If an I/O error occurs
       */
      Appendable append(char c) throws IOException;
  }
  