001/* Appendable.java -- Something to which characters can be appended 002 Copyright (C) 2004 Free Software Foundation 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038package java.lang; 039 040import java.io.IOException; 041 042/** 043 * <p> 044 * An <code>Appendable</code> object is one to which a sequence of Unicode 045 * characters can be added. The appended characters must be valid Unicode 046 * characters, and may include supplementary characters, composed of multiple 047 * 16-bit <code>char</code> values. 048 * </p> 049 * <p> 050 * The behaviour of the <code>Appendable</code> object is heavily dependent 051 * on the particular implementation being used. Some implementations may be 052 * thread-safe, while others may not. Likewise, some implementing classes 053 * may produce errors which aren't propogated to the invoking class, due 054 * to differences in the error handling used. 055 * </p> 056 * <p> 057 * <strong>Note</strong>: implementation of this interface is required for 058 * any class that wishes to receive data from a <code>Formatter</code> 059 * instance. 060 * </p> 061 * 062 * @author Tom Tromey (tromey@redhat.com) 063 * @author Andrew John Hughes (gnu_andrew@member.fsf.org) 064 * @since 1.5 065 */ 066public interface Appendable 067{ 068 069 /** 070 * Appends the Unicode character, c, to this <code>Appendable</code> 071 * object. 072 * 073 * @param c the character to append. 074 * @return a reference to this object. 075 * @throws IOException if an I/O error occurs. 076 */ 077 Appendable append(char c) 078 throws IOException; 079 080 /** 081 * Appends the specified sequence of Unicode characters to this 082 * <code>Appendable</code> object. The entire sequence may not 083 * be appended, if constrained by the underlying implementation. 084 * For example, a buffer may reach its size limit before the entire 085 * sequence is appended. 086 * 087 * @param seq the character sequence to append. If seq is null, 088 * then the string "null" (the string representation of null) 089 * is appended. 090 * @return a reference to this object. 091 * @throws IOException if an I/O error occurs. 092 */ 093 Appendable append(CharSequence seq) 094 throws IOException; 095 096 /** 097 * Appends the specified subsequence of Unicode characters to this 098 * <code>Appendable</code> object, starting and ending at the specified 099 * positions within the sequence. The entire sequence may not 100 * be appended, if constrained by the underlying implementation. 101 * For example, a buffer may reach its size limit before the entire 102 * sequence is appended. The behaviour of this method matches the 103 * behaviour of <code>append(seq.subSequence(start,end))</code> when 104 * the sequence is not null. 105 * 106 * @param seq the character sequence to append. If seq is null, 107 * then the string "null" (the string representation of null) 108 * is appended. 109 * @param start the index of the first Unicode character to use from 110 * the sequence. 111 * @param end the index of the last Unicode character to use from the 112 * sequence. 113 * @return a reference to this object. 114 * @throws IOException if an I/O error occurs. 115 * @throws IndexOutOfBoundsException if either of the indices are negative, 116 * the start index occurs after the end index, or the end index is 117 * beyond the end of the sequence. 118 */ 119 Appendable append(CharSequence seq, int start, int end) 120 throws IOException; 121 122}