1 /* 2 * Copyright (c) 1996, 2005, 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.io; 27 28 29 /** 30 * Abstract class for reading filtered character streams. 31 * The abstract class <code>FilterReader</code> itself 32 * provides default methods that pass all requests to 33 * the contained stream. Subclasses of <code>FilterReader</code> 34 * should override some of these methods and may also provide 35 * additional methods and fields. 36 * 37 * @author Mark Reinhold 38 * @since 1.1 39 */ 40 41 public abstract class FilterReader extends Reader { 42 43 /** 44 * The underlying character-input stream. 45 */ 46 protected Reader in; 47 48 /** 49 * Creates a new filtered reader. 50 * 51 * @param in a Reader object providing the underlying stream. 52 * @throws NullPointerException if <code>in</code> is <code>null</code> 53 */ 54 protected FilterReader(Reader in) { 55 super(in); 56 this.in = in; 57 } 58 59 /** 60 * Reads a single character. 61 * 62 * @exception IOException If an I/O error occurs 63 */ 64 public int read() throws IOException { 65 return in.read(); 66 } 67 68 /** 69 * Reads characters into a portion of an array. 70 * 71 * @exception IOException If an I/O error occurs 72 * @exception IndexOutOfBoundsException {@inheritDoc} 73 */ 74 public int read(char[] cbuf, int off, int len) throws IOException { 75 return in.read(cbuf, off, len); 76 } 77 78 /** 79 * Skips characters. 80 * 81 * @exception IOException If an I/O error occurs 82 */ 83 public long skip(long n) throws IOException { 84 return in.skip(n); 85 } 86 87 /** 88 * Tells whether this stream is ready to be read. 89 * 90 * @exception IOException If an I/O error occurs 91 */ 92 public boolean ready() throws IOException { 93 return in.ready(); 94 } 95 96 /** 97 * Tells whether this stream supports the mark() operation. 98 */ 99 public boolean markSupported() { 100 return in.markSupported(); 101 } 102 103 /** 104 * Marks the present position in the stream. 105 * 106 * @exception IOException If an I/O error occurs 107 */ 108 public void mark(int readAheadLimit) throws IOException { 109 in.mark(readAheadLimit); 110 } 111 112 /** 113 * Resets the stream. 114 * 115 * @exception IOException If an I/O error occurs 116 */ 117 public void reset() throws IOException { 118 in.reset(); 119 } 120 121 public void close() throws IOException { 122 in.close(); 123 } 124 125 }