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 JDK1.1 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 */ FilterReader(Reader in)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 */ read()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 */ read(char cbuf[], int off, int len)73 public int read(char cbuf[], int off, int len) throws IOException { 74 return in.read(cbuf, off, len); 75 } 76 77 /** 78 * Skips characters. 79 * 80 * @exception IOException If an I/O error occurs 81 */ skip(long n)82 public long skip(long n) throws IOException { 83 return in.skip(n); 84 } 85 86 /** 87 * Tells whether this stream is ready to be read. 88 * 89 * @exception IOException If an I/O error occurs 90 */ ready()91 public boolean ready() throws IOException { 92 return in.ready(); 93 } 94 95 /** 96 * Tells whether this stream supports the mark() operation. 97 */ markSupported()98 public boolean markSupported() { 99 return in.markSupported(); 100 } 101 102 /** 103 * Marks the present position in the stream. 104 * 105 * @exception IOException If an I/O error occurs 106 */ mark(int readAheadLimit)107 public void mark(int readAheadLimit) throws IOException { 108 in.mark(readAheadLimit); 109 } 110 111 /** 112 * Resets the stream. 113 * 114 * @exception IOException If an I/O error occurs 115 */ reset()116 public void reset() throws IOException { 117 in.reset(); 118 } 119 close()120 public void close() throws IOException { 121 in.close(); 122 } 123 124 } 125