Package org.apache.commons.io.output

Class ProxyCollectionWriter

java.lang.Object

java.io.Writer

org.apache.commons.io.output.FilterCollectionWriter

org.apache.commons.io.output.ProxyCollectionWriter

All Implemented Interfaces:

java.io.Closeable, java.io.Flushable, java.lang.Appendable, java.lang.AutoCloseable

Direct Known Subclasses:

TeeWriter

public class ProxyCollectionWriter
extends FilterCollectionWriter

A Proxy stream collection which acts as expected, that is it passes the method calls on to the proxied streams and doesn't change which methods are being called. It is an alternative base class to FilterWriter and FilterCollectionWriter to increase reusability, because FilterWriter changes the methods being called, such as write(char[]) to write(char[], int, int) and write(String) to write(String, int, int). This is in contrast to ProxyWriter which is backed by a single Writer.

Since:

2.7

Field Summary

Fields inherited from class org.apache.commons.io.output.FilterCollectionWriter

EMPTY_WRITERS, writers

Fields inherited from class java.io.Writer

lock

Constructor Summary

Constructors

Constructor	Description
ProxyCollectionWriter(java.io.Writer... writers)	Creates a new proxy collection writer.
ProxyCollectionWriter(java.util.Collection<java.io.Writer> writers)	Creates a new proxy collection writer.

Method Summary

Modifier and Type	Method	Description
protected void	afterWrite(int n)	Invoked by the write methods after the proxied call has returned successfully.
java.io.Writer	append(char c)	Invokes the delegates' append(char) methods.
java.io.Writer	append(java.lang.CharSequence csq)	Invokes the delegates' append(CharSequence) methods.
java.io.Writer	append(java.lang.CharSequence csq, int start, int end)	Invokes the delegates' append(CharSequence, int, int) methods.
protected void	beforeWrite(int n)	Invoked by the write methods before the call is proxied.
void	close()	Invokes the delegate's close() method.
void	flush()	Invokes the delegate's flush() method.
protected void	handleIOException(java.io.IOException e)	Handle any IOExceptions thrown.
void	write(char[] cbuf)	Invokes the delegate's write(char[]) method.
void	write(char[] cbuf, int off, int len)	Invokes the delegate's write(char[], int, int) method.
void	write(int c)	Invokes the delegate's write(int) method.
void	write(java.lang.String str)	Invokes the delegate's write(String) method.
void	write(java.lang.String str, int off, int len)	Invokes the delegate's write(String) method.

Methods inherited from class java.io.Writer

nullWriter

Methods inherited from class java.lang.Object

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

Constructor Detail

ProxyCollectionWriter

public ProxyCollectionWriter(java.util.Collection<java.io.Writer> writers)

Creates a new proxy collection writer.

Parameters:

writers - Writers object to provide the underlying targets.

ProxyCollectionWriter

public ProxyCollectionWriter(java.io.Writer... writers)

Creates a new proxy collection writer.

Parameters:

writers - Writers to provide the underlying targets.

Method Detail

afterWrite

protected void afterWrite(int n)
                   throws java.io.IOException

Invoked by the write methods after the proxied call has returned successfully. The number of chars written (1 for the write(int) method, buffer length for write(char[]), etc.) is given as an argument.

Subclasses can override this method to add common post-processing functionality without having to override all the write methods. The default implementation does nothing.

Parameters:

n - number of chars written

Throws:

java.io.IOException - if the post-processing fails

append

public java.io.Writer append(char c)
                      throws java.io.IOException

Invokes the delegates' append(char) methods.

Specified by:

append in interface java.lang.Appendable

Overrides:

append in class FilterCollectionWriter

Parameters:

c - The character to write

Returns:

this writer

Throws:

java.io.IOException - if an I/O error occurs.

Since:

2.0

append

public java.io.Writer append(java.lang.CharSequence csq)
                      throws java.io.IOException

Invokes the delegates' append(CharSequence) methods.

Specified by:

append in interface java.lang.Appendable

Overrides:

append in class FilterCollectionWriter

Parameters:

csq - The character sequence to write

Returns:

this writer

Throws:

java.io.IOException - if an I/O error occurs.

append

public java.io.Writer append(java.lang.CharSequence csq,
                             int start,
                             int end)
                      throws java.io.IOException

Invokes the delegates' append(CharSequence, int, int) methods.

Specified by:

append in interface java.lang.Appendable

Overrides:

append in class FilterCollectionWriter

Parameters:

csq - The character sequence to write

start - The index of the first character to write

end - The index of the first character to write (exclusive)

Returns:

this writer

Throws:

java.io.IOException - if an I/O error occurs.

beforeWrite

protected void beforeWrite(int n)
                    throws java.io.IOException

Invoked by the write methods before the call is proxied. The number of chars to be written (1 for the write(int) method, buffer length for write(char[]), etc.) is given as an argument.

Subclasses can override this method to add common pre-processing functionality without having to override all the write methods. The default implementation does nothing.

Parameters:

n - number of chars to be written

Throws:

java.io.IOException - if the pre-processing fails

close

public void close()
           throws java.io.IOException

Invokes the delegate's close() method.

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface java.io.Closeable

Overrides:

close in class FilterCollectionWriter

Throws:

java.io.IOException - if an I/O error occurs.

flush

public void flush()
           throws java.io.IOException

Invokes the delegate's flush() method.

Specified by:

flush in interface java.io.Flushable

Overrides:

flush in class FilterCollectionWriter

Throws:

java.io.IOException - if an I/O error occurs.

handleIOException

protected void handleIOException(java.io.IOException e)
                          throws java.io.IOException

Handle any IOExceptions thrown.

This method provides a point to implement custom exception handling. The default behavior is to re-throw the exception.

Parameters:

e - The IOException thrown

Throws:

java.io.IOException - if an I/O error occurs.

write

public void write(char[] cbuf)
           throws java.io.IOException

Invokes the delegate's write(char[]) method.

Overrides:

write in class FilterCollectionWriter

Parameters:

cbuf - the characters to write

Throws:

java.io.IOException - if an I/O error occurs.

write

public void write(char[] cbuf,
                  int off,
                  int len)
           throws java.io.IOException

Invokes the delegate's write(char[], int, int) method.

Overrides:

write in class FilterCollectionWriter

Parameters:

cbuf - the characters to write

off - The start offset

len - The number of characters to write

Throws:

java.io.IOException - if an I/O error occurs.

write

public void write(int c)
           throws java.io.IOException

Invokes the delegate's write(int) method.

Overrides:

write in class FilterCollectionWriter

Parameters:

c - the character to write

Throws:

java.io.IOException - if an I/O error occurs.

write

public void write(java.lang.String str)
           throws java.io.IOException

Invokes the delegate's write(String) method.

Overrides:

write in class FilterCollectionWriter

Parameters:

str - the string to write

Throws:

java.io.IOException - if an I/O error occurs.

write

public void write(java.lang.String str,
                  int off,
                  int len)
           throws java.io.IOException

Invokes the delegate's write(String) method.

Overrides:

write in class FilterCollectionWriter

Parameters:

str - the string to write

off - The start offset

len - The number of characters to write

Throws:

java.io.IOException - if an I/O error occurs.