sdk/sources/android-25/java/io/FilterReader.java

   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      */
  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      */
  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      */
  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      */
  91     public boolean ready() throws IOException {
  92         return in.ready();
  93     }
  94
  95     /**
  96      * Tells whether this stream supports the mark() operation.
  97      */
  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      */
 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      */
 116     public void reset() throws IOException {
 117         in.reset();
 118     }
 119
 120     public void close() throws IOException {
 121         in.close();
 122     }
 123
 124 }