186 lines
5.7 KiB
Java
186 lines
5.7 KiB
Java
/* FilterReader.java -- Base class for char stream classes that filter input
|
|
Copyright (C) 1998, 1999, 2001, 2003 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., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 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 numBytes 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
|
|
|