/*
 
* 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;
}