ProxyCollectionWriter (Apache Commons IO 2.7 API)

java.lang.Object
- java.io.Writer
- - org.apache.commons.io.output.FilterCollectionWriter
  - - org.apache.commons.io.output.ProxyCollectionWriter

All Implemented Interfaces:

Closeable, Flushable, Appendable, 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 and Description
`ProxyCollectionWriter(Collection<Writer> writers)` Creates a new proxy collection writer.
`ProxyCollectionWriter(Writer... writers)` Creates a new proxy collection writer.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected void`	`afterWrite(int n)` Invoked by the write methods after the proxied call has returned successfully.
`Writer`	`append(char c)` Invokes the delegates' `append(char)` methods.
`Writer`	`append(CharSequence csq)` Invokes the delegates' `append(CharSequence)` methods.
`Writer`	`append(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(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(String str)` Invokes the delegate's `write(String)` method.
`void`	`write(String str, int off, 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
  - ProxyCollectionWriter
```
public ProxyCollectionWriter(Collection<Writer> writers)
```
    Creates a new proxy collection writer.
    
    Parameters:
    
    writers - Writers object to provide the underlying targets.
  - ProxyCollectionWriter
```
public ProxyCollectionWriter(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 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
  - append
```
public Writer append(char c)
              throws IOException
```
    Invokes the delegates' append(char) methods.
    
    Specified by:
    
    append in interface Appendable
    
    Overrides:
    
    append in class FilterCollectionWriter
    
    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)
              throws IOException
```
    Invokes the delegates' append(CharSequence) methods.
    
    Specified by:
    
    append in interface Appendable
    
    Overrides:
    
    append in class FilterCollectionWriter
    
    Parameters:
    
    csq - The character sequence to write
    
    Returns:
    
    this writer
    
    Throws:
    
    IOException - if an I/O error occurs
  - append
```
public Writer append(CharSequence csq,
                     int start,
                     int end)
              throws IOException
```
    Invokes the delegates' append(CharSequence, int, int) methods.
    
    Specified by:
    
    append in interface 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:
    
    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
  - close
```
public void close()
           throws IOException
```
    Invokes the delegate's close() method.
    
    Specified by:
    
    close in interface Closeable
    
    Specified by:
    
    close in interface AutoCloseable
    
    Overrides:
    
    close in class FilterCollectionWriter
    
    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 FilterCollectionWriter
    
    Throws:
    
    IOException - if an I/O error occurs
  - handleIOException
```
protected void handleIOException(IOException e)
                          throws 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:
    
    IOException - if an I/O error occurs
  - write
```
public void write(char[] cbuf)
           throws IOException
```
    Invokes the delegate's write(char[]) method.
    
    Overrides:
    
    write in class FilterCollectionWriter
    
    Parameters:
    
    cbuf - the characters to write
    
    Throws:
    
    IOException - if an I/O error occurs
  - write
```
public void write(char[] cbuf,
                  int off,
                  int len)
           throws 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:
    
    IOException - if an I/O error occurs
  - write
```
public void write(int c)
           throws IOException
```
    Invokes the delegate's write(int) method.
    
    Overrides:
    
    write in class FilterCollectionWriter
    
    Parameters:
    
    c - the character 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 FilterCollectionWriter
    
    Parameters:
    
    str - the string to write
    
    Throws:
    
    IOException - if an I/O error occurs
  - write
```
public void write(String str,
                  int off,
                  int len)
           throws 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:
    
    IOException - if an I/O error occurs

Class ProxyCollectionWriter

Field Summary

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

Fields inherited from class java.io.Writer

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

ProxyCollectionWriter

ProxyCollectionWriter

Method Detail

afterWrite

append

append

append

beforeWrite

close

flush

handleIOException

write

write

write

write

write