FilterWriter

AI-generated Key Takeaways

• FilterWriter is an abstract class for writing filtered character streams, extending the Writer class.

• It provides default methods that pass requests to the contained stream, allowing subclasses to override for custom filtering.

• Subclasses can extend FilterWriter by overriding methods like close, flush, and write to modify stream behavior.

• A FilterWriter is constructed with an underlying Writer object to which it delegates operations.

• FilterWriter includes methods for closing the stream, flushing the stream, and writing characters, strings, and character arrays.

public abstract class FilterWriter extends Writer

Abstract class for writing filtered character streams. The abstract class FilterWriter itself provides default methods that pass all requests to the contained stream. Subclasses of FilterWriter should override some of these methods and may also provide additional methods and fields.

Field Summary

protected Writer

out

The underlying character-output stream.

Inherited Field Summary

From class java.io.Writer

protected Object

lock

The object used to synchronize operations on this stream.

Protected Constructor Summary

FilterWriter(Writer out) Create a new filtered writer.

Public Method Summary

void	close() Closes the stream, flushing it first.
void	flush() Flushes the stream.
void	write(int c) Writes a single character.
void	write(String str, int off, int len) Writes a portion of a string.
void	write(char[] cbuf, int off, int len) Writes a portion of an array of characters.

Inherited Method Summary

From class java.io.Writer

Writer	append(char c) Appends the specified character to this writer.
Writer	append(CharSequence csq, int start, int end) Appends a subsequence of the specified character sequence to this writer.
Writer	append(CharSequence csq) Appends the specified character sequence to this writer.
abstract void	close() Closes the stream, flushing it first.
abstract void	flush() Flushes the stream.
void	write(String str) Writes a string.
void	write(int c) Writes a single character.
void	write(String str, int off, int len) Writes a portion of a string.
abstract void	write(char[] cbuf, int off, int len) Writes a portion of an array of characters.
void	write(char[] cbuf) Writes an array of characters.

From class java.lang.Object

Object	clone() Creates and returns a copy of this Object.
boolean	equals(Object obj) 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(long timeout, 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 timeout) 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() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

From interface java.lang.Appendable

abstract Appendable	append(char c) Appends the specified character to this Appendable.
abstract Appendable	append(CharSequence csq, int start, int end) Appends a subsequence of the specified character sequence to this Appendable.
abstract Appendable	append(CharSequence csq) Appends the specified character sequence to this Appendable.

From interface java.io.Closeable

abstract void

close() Closes this stream and releases any system resources associated with it.

From interface java.io.Flushable

abstract void

flush() Flushes this stream by writing any buffered output to the underlying stream.

From interface java.lang.AutoCloseable

abstract void

close() Closes this resource, relinquishing any underlying resources.

Fields

protected Writer out

The underlying character-output stream.

Protected Constructors

protected FilterWriter (Writer out)

Create a new filtered writer.

Parameters

out	a Writer object to provide the underlying stream.

Throws

NullPointerException	if out is null

Public Methods

public void close ()

Closes the stream, flushing it first. Once the stream has been closed, further write() or flush() invocations will cause an IOException to be thrown. Closing a previously closed stream has no effect.

Throws

IOException

public void flush ()

Flushes the stream.

Throws

IOException	If an I/O error occurs

public void write (int c)

Writes a single character.

Parameters

c	int specifying a character to be written

Throws

IOException	If an I/O error occurs

public void write (String str, int off, int len)

Writes a portion of a string.

Parameters

str	String to be written
off	Offset from which to start reading characters
len	Number of characters to be written

Throws

IOException	If an I/O error occurs

public void write (char[] cbuf, int off, int len)

Writes a portion of an array of characters.

Parameters

cbuf	Buffer of characters to be written
off	Offset from which to start reading characters
len	Number of characters to be written

Throws

IOException	If an I/O error occurs