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 } 122
