| /* FilterReader.java -- Base class for char stream classes that filter input |
| Copyright (C) 1998, 1999, 2001, 2003, 2005 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package java.io; |
| |
| /* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3 |
| * "The Java Language Specification", ISBN 0-201-63451-1 |
| * plus online API docs for JDK 1.2 beta from http://www.javasoft.com. |
| * Status: Believed complete and correct. |
| */ |
| |
| /** |
| * This is the common superclass of all standard classes that filter |
| * input. It acts as a layer on top of an underlying <code>Reader</code> |
| * and simply redirects calls made to it to the subordinate Reader |
| * instead. Subclasses of this class perform additional filtering |
| * functions in addition to simply redirecting the call. |
| * <p> |
| * When creating a subclass of <code>FilterReader</code>, override the |
| * appropriate methods to implement the desired filtering. However, note |
| * that the <code>read(char[])</code> method does not need to be overridden |
| * as this class redirects calls to that method to |
| * <code>read(yte[], int, int)</code> instead of to the subordinate |
| * <code>Reader} read(yte[])</code> method. |
| * |
| * @author Aaron M. Renn (arenn@urbanophile.com) |
| * @author Warren Levy (warrenl@cygnus.com) |
| */ |
| public abstract class FilterReader extends Reader |
| { |
| /** |
| * This is the subordinate <code>Reader</code> to which method calls |
| * are redirected |
| */ |
| protected Reader in; |
| |
| /** |
| * Create a <code>FilterReader</code> with the specified subordinate |
| * <code>Reader</code>. |
| * The <code>lock</code> of the new <code>FilterReader</code> will be set |
| * to <code>in.lock</code>. |
| * |
| * @param in The subordinate <code>Reader</code> |
| */ |
| protected FilterReader(Reader in) |
| { |
| super(in.lock); |
| this.in = in; |
| } |
| |
| /** |
| * Calls the <code>in.mark(int)</code> method. |
| * |
| * @param readlimit The parameter passed to <code>in.mark(int)</code> |
| * |
| * @exception IOException If an error occurs |
| */ |
| public void mark(int readlimit) throws IOException |
| { |
| in.mark(readlimit); |
| } |
| |
| /** |
| * Calls the <code>in.markSupported()</code> method. |
| * |
| * @return <code>true</code> if mark/reset is supported, |
| * <code>false</code> otherwise |
| */ |
| public boolean markSupported() |
| { |
| return(in.markSupported()); |
| } |
| |
| /** |
| * Calls the <code>in.reset()</code> method. |
| * |
| * @exception IOException If an error occurs |
| */ |
| public void reset() throws IOException |
| { |
| in.reset(); |
| } |
| |
| /** |
| * Calls the <code>in.read()</code> method. |
| * |
| * @return The value returned from <code>in.available()</code> |
| * |
| * @exception IOException If an error occurs |
| */ |
| public boolean ready() throws IOException |
| { |
| return(in.ready()); |
| } |
| |
| /** |
| * Calls the <code>in.skip(long)</code> method |
| * |
| * @param num_chars The requested number of chars to skip. |
| * |
| * @return The value returned from <code>in.skip(long)</code> |
| * |
| * @exception IOException If an error occurs |
| */ |
| public long skip(long num_chars) throws IOException |
| { |
| return(in.skip(num_chars)); |
| } |
| |
| /** |
| * Calls the <code>in.read()</code> method |
| * |
| * @return The value returned from <code>in.read()</code> |
| * |
| * @exception IOException If an error occurs |
| */ |
| public int read() throws IOException |
| { |
| return(in.read()); |
| } |
| |
| /** |
| * Calls the <code>in.read(char[], int, int)</code> method. |
| * |
| * @param buf The buffer to read chars into |
| * @param offset The index into the buffer to start storing chars |
| * @param len The maximum number of chars to read. |
| * |
| * @return The value retured from <code>in.read(char[], int, int)</code> |
| * |
| * @exception IOException If an error occurs |
| */ |
| public int read(char[] buf, int offset, int len) throws IOException |
| { |
| return(in.read(buf, offset, len)); |
| } |
| |
| /** |
| * This method closes the stream by calling the <code>close()</code> method |
| * of the underlying stream. |
| * |
| * @exception IOException If an error occurs |
| */ |
| public void close() throws IOException |
| { |
| in.close(); |
| } |
| |
| } // class FilterReader |
| |