Added in API level 1

public abstract class

FilterReader

extends Reader

java.lang.Object
↳	java.io.Reader
	↳	java.io.FilterReader

Known Direct Subclasses

PushbackReader

Class Overview

Wraps an existing Reader and performs some transformation on the input data while it is being read. Transformations can be anything from a simple byte-wise filtering input data to an on-the-fly compression or decompression of the underlying reader. Readers that wrap another reader and provide some additional functionality on top of it usually inherit from this class.

Summary

Fields
protected Reader	in	The target Reader which is being filtered.

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Inherited Fields

From class java.io.Reader

Protected Constructors
	FilterReader(Reader in) Constructs a new FilterReader on the Reader `in`.

Public Methods
void	close() Closes this reader.
synchronized void	mark(int readlimit) Sets a mark position in this reader.
boolean	markSupported() Indicates whether this reader supports `mark()` and `reset()`.
int	read() Reads a single character from the filtered reader and returns it as an integer with the two higher-order bytes set to 0.
int	read(char[] buffer, int offset, int count) Reads up to `count` characters from the filtered reader and stores them in the byte array `buffer` starting at `offset`.
boolean	ready() Indicates whether this reader is ready to be read without blocking.
void	reset() Resets this reader's position to the last marked location.
long	skip(long charCount) Skips `charCount` characters in this reader.

[Expand]

Inherited Methods

From class java.io.Reader

abstract void	close() Closes this reader.
void	mark(int readLimit) Sets a mark position in this reader.
boolean	markSupported() Indicates whether this reader supports the `mark()` and `reset()` methods.
int	read() Reads a single character from this reader and returns it as an integer with the two higher-order bytes set to 0.
abstract int	read(char[] buffer, int offset, int count) Reads up to `count` characters from this reader and stores them at `offset` in the character array `buffer`.
int	read(CharBuffer target) Reads characters and puts them into the `target` character buffer.
int	read(char[] buffer) Reads characters from this reader and stores them in the character array `buffer` starting at offset 0.
boolean	ready() Indicates whether this reader is ready to be read without blocking.
void	reset() Resets this reader's position to the last `mark()` location.
long	skip(long charCount) Skips `charCount` characters in this reader.

From class java.lang.Object

Object	clone() Creates and returns a copy of this `Object`.
boolean	equals(Object o) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of `Class` that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object.
final void	wait(long millis, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait(long millis) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.

From interface java.lang.Readable

From interface java.io.Closeable

From interface java.lang.AutoCloseable

Fields

protected Reader in

Added in API level 1

The target Reader which is being filtered.

Protected Constructors

protected FilterReader (Reader in)

Added in API level 1

Constructs a new FilterReader on the Reader in.

Parameters

in	The non-null Reader to filter reads on.

Public Methods

public void close ()

Added in API level 1

Closes this reader. This implementation closes the filtered reader.

Throws

IOException	if an error occurs while closing this reader.

public synchronized void mark (int readlimit)

Added in API level 1

Sets a mark position in this reader. The parameter readlimit indicates how many bytes can be read before the mark is invalidated. Sending reset() will reposition this reader back to the marked position, provided that readlimit has not been surpassed.

This implementation sets a mark in the filtered reader.

Parameters

readlimit	the number of bytes that can be read from this reader before the mark is invalidated.

Throws

IOException	if an error occurs while marking this reader.

public boolean markSupported ()

Added in API level 1

Indicates whether this reader supports mark() and reset(). This implementation returns whether the filtered reader supports marking.

Returns

true if mark() and reset() are supported by the filtered reader, false otherwise.

public int read ()

Added in API level 1

Reads a single character from the filtered reader and returns it as an integer with the two higher-order bytes set to 0. Returns -1 if the end of the filtered reader has been reached.

Returns

The character read or -1 if the end of the filtered reader has been reached.

Throws

IOException	if an error occurs while reading from this reader.

public int read (char[] buffer, int offset, int count)

Added in API level 1

Reads up to count characters from the filtered reader and stores them in the byte array buffer starting at offset. Returns the number of characters actually read or -1 if no characters were read and the end of the filtered reader was encountered.

Throws

IOException	if an error occurs while reading from this reader.

public boolean ready ()

Added in API level 1

Indicates whether this reader is ready to be read without blocking. If the result is true, the next read() will not block. If the result is false, this reader may or may not block when read() is sent.

Returns

true if this reader will not block when read() is called, false if unknown or blocking will occur.

Throws

IOException	if the reader is closed or some other I/O error occurs.

public void reset ()

Added in API level 1

Resets this reader's position to the last marked location. Invocations of read() and skip() will occur from this new location. If this reader was not marked, the behavior depends on the implementation of reset() in the Reader subclass that is filtered by this reader. The default behavior for Reader is to throw an IOException.

Throws

IOException	if a problem occurred or the filtered reader does not support `mark()` and `reset()`.

public long skip (long charCount)

Added in API level 1

Skips charCount characters in this reader. Subsequent calls to read will not return these characters unless reset is used. The default implementation is to skip characters in the filtered reader.

Returns

the number of characters actually skipped.

Throws

IOException	if the filtered reader is closed or some other I/O error occurs.

Results

Interfaces

Classes

Exceptions

Errors

FilterReader

Class Overview

See Also

Summary

Fields

protected Reader in

Protected Constructors

protected FilterReader (Reader in)

Parameters

Public Methods

public void close ()

Throws

public synchronized void mark (int readlimit)

Parameters

Throws

See Also

public boolean markSupported ()

Returns

See Also

public int read ()

Returns

Throws

public int read (char[] buffer, int offset, int count)

Throws

public boolean ready ()

Returns

Throws

public void reset ()

Throws

See Also

public long skip (long charCount)

Returns

Throws

See Also