Package 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:

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

Direct Known Subclasses:

CloseShieldWriter, FileWriterWithEncoding, TaggedWriter

public class ProxyWriter
extends java.io.FilterWriter

A writer proxy which delegates to the wrapped writer.

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).

Field Summary

Fields inherited from class java.io.FilterWriter

out

Fields inherited from class java.io.Writer

lock

Constructor Summary

Constructors

Constructor	Description
ProxyWriter(java.io.Writer delegate)	Constructs a new ProxyWriter.

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 delegate's append(char) method.
java.io.Writer	append(java.lang.CharSequence csq)	Invokes the delegate's append(CharSequence) method.
java.io.Writer	append(java.lang.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(java.io.IOException e)	Handles any IOExceptions thrown.
ProxyWriter	setReference(java.io.Writer out)	Sets the underlying writer.
java.io.Writer	unwrap()	Unwraps this instance by returning the underlying Writer.
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

ProxyWriter

public ProxyWriter(java.io.Writer delegate)

Constructs a new ProxyWriter.

Parameters:

delegate - the Writer to delegate to.

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.

Since:

2.0

append

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

Invokes the delegate's append(char) method.

Specified by:

append in interface java.lang.Appendable

Overrides:

append in class java.io.Writer

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 delegate's append(CharSequence) method.

Specified by:

append in interface java.lang.Appendable

Overrides:

append in class java.io.Writer

Parameters:

csq - The character sequence 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,
                             int start,
                             int end)
                      throws java.io.IOException

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

Specified by:

append in interface java.lang.Appendable

Overrides:

append in class java.io.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:

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

Since:

2.0

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.

Since:

2.0

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 java.io.FilterWriter

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 java.io.FilterWriter

Throws:

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

handleIOException

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

Handles 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.

Since:

2.0

setReference

public ProxyWriter setReference(java.io.Writer out)

Sets the underlying writer.

Use with caution.

Parameters:

out - the underlying output writer.

Returns:

this instance.

Since:

2.22.0

unwrap

public java.io.Writer unwrap()

Unwraps this instance by returning the underlying Writer.

Use with caution.

Returns:

the underlying Writer.

Since:

2.22.0

write

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

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

Overrides:

write in class java.io.Writer

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 java.io.FilterWriter

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 java.io.FilterWriter

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 java.io.Writer

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 java.io.FilterWriter

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.