org.apache.commons.io.output
Class ProxyWriter

java.lang.Object
  java.io.Writer
      java.io.FilterWriter
          org.apache.commons.io.output.ProxyWriter

All Implemented Interfaces:

Closeable, Flushable, Appendable

public class ProxyWriter
extends FilterWriter

A Proxy stream which acts as expected, that is it passes the method calls on to the proxied stream and doesn't change which methods are being called. It is an alternative base class to FilterWriter 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).

Version:

$Id: ProxyWriter.java 1304052 2012-03-22 20:55:29Z ggregory $

Field Summary

Fields inherited from class java.io.FilterWriter

out

Fields inherited from class java.io.Writer

lock

Constructor Summary

ProxyWriter(Writer proxy)
Constructs a new ProxyWriter.

Method Summary

protected void	afterWrite(int n) Invoked by the write methods after the proxied call has returned successfully.
Writer	append(char c) Invokes the delegate's append(char) method.
Writer	append(CharSequence csq) Invokes the delegate's append(CharSequence) method.
Writer	append(CharSequence csq, int start, int end) Invokes the delegate's append(CharSequence, int, int) method.
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(IOException e) Handle any IOExceptions thrown.
void	write(char[] chr) Invokes the delegate's write(char[]) method.
void	write(char[] chr, int st, int len) Invokes the delegate's write(char[], int, int) method.
void	write(int idx) Invokes the delegate's write(int) method.
void	write(String str) Invokes the delegate's write(String) method.
void	write(String str, int st, int len) Invokes the delegate's write(String) method.

Methods inherited from class java.lang.Object

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

Constructor Detail

ProxyWriter

public ProxyWriter(Writer proxy)

Constructs a new ProxyWriter.

Parameters:

proxy - the Writer to delegate to

Method Detail

append

public Writer append(char c)
              throws IOException

Invokes the delegate's append(char) method.

Specified by:

append in interface Appendable

Overrides:

append in class Writer

Parameters:

c - The character to write

Returns:

this writer

Throws:

IOException - if an I/O error occurs

Since:

2.0

append

public Writer append(CharSequence csq,
                     int start,
                     int end)
              throws IOException

Invokes the delegate's append(CharSequence, int, int) method.

Specified by:

append in interface Appendable

Overrides:

append in class Writer

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:

IOException - if an I/O error occurs

Since:

2.0

append

public Writer append(CharSequence csq)
              throws IOException

Invokes the delegate's append(CharSequence) method.

Specified by:

append in interface Appendable

Overrides:

append in class Writer

Parameters:

csq - The character sequence to write

Returns:

this writer

Throws:

IOException - if an I/O error occurs

Since:

2.0

write

public void write(int idx)
           throws IOException

Invokes the delegate's write(int) method.

Overrides:

write in class FilterWriter

Parameters:

idx - the character to write

Throws:

IOException - if an I/O error occurs

write

public void write(char[] chr)
           throws IOException

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

Overrides:

write in class Writer

Parameters:

chr - the characters to write

Throws:

IOException - if an I/O error occurs

write

public void write(char[] chr,
                  int st,
                  int len)
           throws IOException

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

Overrides:

write in class FilterWriter

Parameters:

chr - the characters to write

st - The start offset

len - The number of characters to write

Throws:

IOException - if an I/O error occurs

write

public void write(String str)
           throws IOException

Invokes the delegate's write(String) method.

Overrides:

write in class Writer

Parameters:

str - the string to write

Throws:

IOException - if an I/O error occurs

write

public void write(String str,
                  int st,
                  int len)
           throws IOException

Invokes the delegate's write(String) method.

Overrides:

write in class FilterWriter

Parameters:

str - the string to write

st - The start offset

len - The number of characters to write

Throws:

IOException - if an I/O error occurs

flush

public void flush()
           throws IOException

Invokes the delegate's flush() method.

Specified by:

flush in interface Flushable

Overrides:

flush in class FilterWriter

Throws:

IOException - if an I/O error occurs

close

public void close()
           throws IOException

Invokes the delegate's close() method.

Specified by:

close in interface Closeable

Overrides:

close in class FilterWriter

Throws:

IOException - if an I/O error occurs

beforeWrite

protected void beforeWrite(int n)
                    throws 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:

IOException - if the pre-processing fails

Since:

2.0

afterWrite

protected void afterWrite(int n)
                   throws 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:

IOException - if the post-processing fails

Since:

2.0

handleIOException

protected void handleIOException(IOException e)
                          throws IOException

Handle any IOExceptions thrown.

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

Parameters:

e - The IOException thrown

Throws:

IOException - if an I/O error occurs

Since:

2.0