1 /*

     2  * Copyright (c) 2003, 2004, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 package java.lang;

    27 

    28 import java.io.IOException;

    29 

    30 /**

    31  * An object to which <tt>char</tt> sequences and values can be appended.  The

    32  * <tt>Appendable</tt> interface must be implemented by any class whose

    33  * instances are intended to receive formatted output from a {@link

    34  * java.util.Formatter}.

    35  *

    36  * <p> The characters to be appended should be valid Unicode characters as

    37  * described in <a href="Character.html#unicode">Unicode Character

    38  * Representation</a>.  Note that supplementary characters may be composed of

    39  * multiple 16-bit <tt>char</tt> values.

    40  *

    41  * <p> Appendables are not necessarily safe for multithreaded access.  Thread

    42  * safety is the responsibility of classes that extend and implement this

    43  * interface.

    44  *

    45  * <p> Since this interface may be implemented by existing classes

    46  * with different styles of error handling there is no guarantee that

    47  * errors will be propagated to the invoker.

    48  *

    49  * @since 1.5

    50  */

    51 public interface Appendable {

    52 

    53     /**

    54      * Appends the specified character sequence to this <tt>Appendable</tt>.

    55      *

    56      * <p> Depending on which class implements the character sequence

    57      * <tt>csq</tt>, the entire sequence may not be appended.  For

    58      * instance, if <tt>csq</tt> is a {@link java.nio.CharBuffer} then

    59      * the subsequence to append is defined by the buffer's position and limit.

    60      *

    61      * @param  csq

    62      *         The character sequence to append.  If <tt>csq</tt> is

    63      *         <tt>null</tt>, then the four characters <tt>"null"</tt> are

    64      *         appended to this Appendable.

    65      *

    66      * @return  A reference to this <tt>Appendable</tt>

    67      *

    68      * @throws  IOException

    69      *          If an I/O error occurs

    70      */

    71     Appendable append(CharSequence csq) throws IOException;

    72 

    73     /**

    74      * Appends a subsequence of the specified character sequence to this

    75      * <tt>Appendable</tt>.

    76      *

    77      * <p> An invocation of this method of the form <tt>out.append(csq, start,

    78      * end)</tt> when <tt>csq</tt> is not <tt>null</tt>, behaves in

    79      * exactly the same way as the invocation

    80      *

    81      * <pre>

    82      *     out.append(csq.subSequence(start, end)) </pre>

    83      *

    84      * @param  csq

    85      *         The character sequence from which a subsequence will be

    86      *         appended.  If <tt>csq</tt> is <tt>null</tt>, then characters

    87      *         will be appended as if <tt>csq</tt> contained the four

    88      *         characters <tt>"null"</tt>.

    89      *

    90      * @param  start

    91      *         The index of the first character in the subsequence

    92      *

    93      * @param  end

    94      *         The index of the character following the last character in the

    95      *         subsequence

    96      *

    97      * @return  A reference to this <tt>Appendable</tt>

    98      *

    99      * @throws  IndexOutOfBoundsException

   100      *          If <tt>start</tt> or <tt>end</tt> are negative, <tt>start</tt>

   101      *          is greater than <tt>end</tt>, or <tt>end</tt> is greater than

   102      *          <tt>csq.length()</tt>

   103      *

   104      * @throws  IOException

   105      *          If an I/O error occurs

   106      */

   107     Appendable append(CharSequence csq, int start, int end) throws IOException;

   108 

   109     /**

   110      * Appends the specified character to this <tt>Appendable</tt>.

   111      *

   112      * @param  c

   113      *         The character to append

   114      *

   115      * @return  A reference to this <tt>Appendable</tt>

   116      *

   117      * @throws  IOException

   118      *          If an I/O error occurs

   119      */

   120     Appendable append(char c) throws IOException;

   121 }