001/* FilterWriter.java -- Parent class for output streams that filter 002 Copyright (C) 1998, 1999, 2001, 2003, 2005 Free Software Foundation, Inc. 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. */ 037 038 039package java.io; 040 041/* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3 042 * "The Java Language Specification", ISBN 0-201-63451-1 043 * Status: Complete to version 1.1. 044 */ 045 046/** 047 * This class is the common superclass of output character stream classes 048 * that filter the output they write. These classes typically transform the 049 * data in some way prior to writing it out to another underlying 050 * <code>Writer</code>. This class simply overrides all the 051 * methods in <code>Writer</code> to redirect them to the 052 * underlying stream. Subclasses provide actual filtering. 053 * 054 * @author Aaron M. Renn (arenn@urbanophile.com) 055 * @author Tom Tromey (tromey@cygnus.com) 056 */ 057public abstract class FilterWriter extends Writer 058{ 059 /** 060 * This is the subordinate <code>Writer</code> that this class 061 * redirects its method calls to. 062 */ 063 protected Writer out; 064 065 /** 066 * This method initializes an instance of <code>FilterWriter</code> 067 * to write to the specified subordinate <code>Writer</code>. 068 * The given <code>Writer</code> will be used as <code>lock</code> for 069 * the newly created <code>FilterWriter</code>. 070 * 071 * @param out The <code>Writer</code> to write to 072 */ 073 protected FilterWriter(Writer out) 074 { 075 super(out.lock); 076 this.out = out; 077 } 078 079 /** 080 * This method closes the underlying <code>Writer</code>. Any 081 * further attempts to write to this stream may throw an exception. 082 * 083 * @exception IOException If an error occurs 084 */ 085 public void close() throws IOException 086 { 087 out.close(); 088 } 089 090 /** 091 * This method attempt to flush all buffered output to be written to the 092 * underlying output sink. 093 * 094 * @exception IOException If an error occurs 095 */ 096 public void flush() throws IOException 097 { 098 out.flush(); 099 } 100 101 /** 102 * This method writes a single char of output to the underlying 103 * <code>Writer</code>. 104 * 105 * @param b The char to write, passed as an int. 106 * 107 * @exception IOException If an error occurs 108 */ 109 public void write(int b) throws IOException 110 { 111 out.write(b); 112 } 113 114 /** 115 * This method writes <code>len</code> chars from the array <code>buf</code> 116 * starting at index <code>offset</code> to the underlying 117 * <code>Writer</code>. 118 * 119 * @param buf The char array to write chars from 120 * @param offset The index into the array to start writing chars from 121 * @param len The number of chars to write 122 * 123 * @exception IOException If an error occurs 124 */ 125 public void write(char[] buf, int offset, int len) throws IOException 126 { 127 out.write(buf, offset, len); 128 } 129 130 /** 131 * This method writes <code>len</code> chars from the <code>String</code> 132 * starting at position <code>offset</code>. 133 * 134 * @param str The <code>String</code> that is to be written 135 * @param offset The character offset into the <code>String</code> 136 * to start writing from 137 * @param len The number of chars to write 138 * 139 * @exception IOException If an error occurs 140 */ 141 public void write(String str, int offset, int len) throws IOException 142 { 143 out.write(str, offset, len); 144 } 145 146} // class FilterWriter 147