java.io

Class FilterReader

java.lang.Object

java.io.Reader

java.io.FilterReader

All Implemented Interfaces:

Closeable

Direct Known Subclasses:

PushbackReader

public abstract class FilterReader
extends Reader

This is the common superclass of all standard classes that filter input. It acts as a layer on top of an underlying Reader 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.

When creating a subclass of FilterReader, override the appropriate methods to implement the desired filtering. However, note that the read(char[]) method does not need to be overridden as this class redirects calls to that method to read(yte[], int, int) instead of to the subordinate Reader} read(yte[]) method.

Author:

Aaron M. Renn (arenn@urbanophile.com), Warren Levy (warrenl@cygnus.com)

Method Summary

Modifier and Type	Method and Description
void	close() This method closes the stream by calling the close() method of the underlying stream.
void	mark(int readlimit) Calls the in.mark(int) method.
boolean	markSupported() Calls the in.markSupported() method.
int	read() Calls the in.read() method
int	read(char[] buf, int offset, int len) Calls the in.read(char[], int, int) method.
boolean	ready() Calls the in.read() method.
void	reset() Calls the in.reset() method.
long	skip(long num_chars) Calls the in.skip(long) method

Methods inherited from class java.io.Reader

read

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

close

public void close()
           throws IOException

This method closes the stream by calling the close() method of the underlying stream.

Specified by:

close in interface Closeable

Specified by:

close in class Reader

Throws:

IOException - If an error occurs

mark

public void mark(int readlimit)
          throws IOException

Calls the in.mark(int) method.

Overrides:

mark in class Reader

Parameters:

readlimit - The parameter passed to in.mark(int)

Throws:

IOException - If an error occurs

markSupported

public boolean markSupported()

Calls the in.markSupported() method.

Overrides:

markSupported in class Reader

Returns:

true if mark/reset is supported, false otherwise

read

public int read()
         throws IOException

Calls the in.read() method

Overrides:

read in class Reader

Returns:

The value returned from in.read()

Throws:

IOException - If an error occurs

read

public int read(char[] buf,
                int offset,
                int len)
         throws IOException

Calls the in.read(char[], int, int) method.

Specified by:

read in class Reader

Parameters:

buf - The buffer to read chars into

offset - The index into the buffer to start storing chars

len - The maximum number of chars to read.

Returns:

The value retured from in.read(char[], int, int)

Throws:

IOException - If an error occurs

ready

public boolean ready()
              throws IOException

Calls the in.read() method.

Overrides:

ready in class Reader

Returns:

The value returned from in.available()

Throws:

IOException - If an error occurs

reset

public void reset()
           throws IOException

Calls the in.reset() method.

Overrides:

reset in class Reader

Throws:

IOException - If an error occurs

skip

public long skip(long num_chars)
          throws IOException

Calls the in.skip(long) method

Overrides:

skip in class Reader

Parameters:

num_chars - The requested number of chars to skip.

Returns:

The value returned from in.skip(long)

Throws:

IOException - If an error occurs