ProxyInputStream (Apache Commons IO 2.5 API)

java.lang.Object
- java.io.InputStream
- - java.io.FilterInputStream
  - - org.apache.commons.io.input.ProxyInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

AutoCloseInputStream, BOMInputStream, CloseShieldInputStream, CountingInputStream, SwappedDataInputStream, TaggedInputStream, TeeInputStream
```
public abstract class ProxyInputStream
extends FilterInputStream
```
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 FilterInputStream to increase reusability, because FilterInputStream changes the methods being called, such as read(byte[]) to read(byte[], int, int).
See the protected methods for ways in which a subclass can easily decorate a stream with custom pre-, post- or error processing functionality.

Version:

$Id: ProxyInputStream.java 1603493 2014-06-18 15:46:07Z ggregory $

Field Summary
- Fields inherited from class java.io.FilterInputStream
  in

Constructor Summary

Constructors
Constructor and Description

ProxyInputStream(InputStream proxy)
Constructs a new ProxyInputStream.

Constructors
Constructor and Description
`ProxyInputStream(InputStream proxy)` Constructs a new ProxyInputStream.

Method Summary

Methods
Modifier and Type	Method and Description
`protected void`	`afterRead(int n)` Invoked by the read methods after the proxied call has returned successfully.
`int`	`available()` Invokes the delegate's `available()` method.
`protected void`	`beforeRead(int n)` Invoked by the read methods before the call is proxied.
`void`	`close()` Invokes the delegate's `close()` method.
`protected void`	`handleIOException(IOException e)` Handle any IOExceptions thrown.
`void`	`mark(int readlimit)` Invokes the delegate's `mark(int)` method.
`boolean`	`markSupported()` Invokes the delegate's `markSupported()` method.
`int`	`read()` Invokes the delegate's `read()` method.
`int`	`read(byte[] bts)` Invokes the delegate's `read(byte[])` method.
`int`	`read(byte[] bts, int off, int len)` Invokes the delegate's `read(byte[], int, int)` method.
`void`	`reset()` Invokes the delegate's `reset()` method.
`long`	`skip(long ln)` Invokes the delegate's `skip(long)` method.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - ProxyInputStream
```
public ProxyInputStream(InputStream proxy)
```
    Constructs a new ProxyInputStream.
    
    Parameters:
    proxy - the InputStream to delegate to
- Method Detail
  - read
```
public int read()
         throws IOException
```
    Invokes the delegate's read() method.
    
    Overrides:
    
    read in class FilterInputStream
    
    Returns:
    the byte read or -1 if the end of stream
    
    Throws:
    
    IOException - if an I/O error occurs
  - read
```
public int read(byte[] bts)
         throws IOException
```
    Invokes the delegate's read(byte[]) method.
    
    Overrides:
    
    read in class FilterInputStream
    
    Parameters:
    bts - the buffer to read the bytes into
    
    Returns:
    the number of bytes read or EOF if the end of stream
    
    Throws:
    
    IOException - if an I/O error occurs
  - read
```
public int read(byte[] bts,
       int off,
       int len)
         throws IOException
```
    Invokes the delegate's read(byte[], int, int) method.
    
    Overrides:
    
    read in class FilterInputStream
    
    Parameters:
    bts - the buffer to read the bytes into
    off - The start offset
    len - The number of bytes to read
    
    Returns:
    the number of bytes read or -1 if the end of stream
    
    Throws:
    
    IOException - if an I/O error occurs
  - skip
```
public long skip(long ln)
          throws IOException
```
    Invokes the delegate's skip(long) method.
    
    Overrides:
    
    skip in class FilterInputStream
    
    Parameters:
    ln - the number of bytes to skip
    
    Returns:
    the actual number of bytes skipped
    
    Throws:
    
    IOException - if an I/O error occurs
  - available
```
public int available()
              throws IOException
```
    Invokes the delegate's available() method.
    
    Overrides:
    
    available in class FilterInputStream
    
    Returns:
    the number of available bytes
    
    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
    
    Specified by:
    
    close in interface AutoCloseable
    
    Overrides:
    
    close in class FilterInputStream
    
    Throws:
    
    IOException - if an I/O error occurs
  - mark
```
public void mark(int readlimit)
```
    Invokes the delegate's mark(int) method.
    
    Overrides:
    
    mark in class FilterInputStream
    
    Parameters:
    readlimit - read ahead limit
  - reset
```
public void reset()
           throws IOException
```
    Invokes the delegate's reset() method.
    
    Overrides:
    
    reset in class FilterInputStream
    
    Throws:
    
    IOException - if an I/O error occurs
  - markSupported
```
public boolean markSupported()
```
    Invokes the delegate's markSupported() method.
    
    Overrides:
    
    markSupported in class FilterInputStream
    
    Returns:
    true if mark is supported, otherwise false
  - beforeRead
```
protected void beforeRead(int n)
                   throws IOException
```
    Invoked by the read methods before the call is proxied. The number of bytes that the caller wanted to read (1 for the read() method, buffer length for read(byte[]), etc.) is given as an argument.
    Subclasses can override this method to add common pre-processing functionality without having to override all the read methods. The default implementation does nothing.
    Note this method is not called from skip(long) or reset(). You need to explicitly override those methods if you want to add pre-processing steps also to them.
    
    Parameters:
    n - number of bytes that the caller asked to be read
    
    Throws:
    
    IOException - if the pre-processing fails
    Since:
    
    2.0
  - afterRead
```
protected void afterRead(int n)
                  throws IOException
```
    Invoked by the read methods after the proxied call has returned successfully. The number of bytes returned to the caller (or -1 if the end of stream was reached) is given as an argument.
    Subclasses can override this method to add common post-processing functionality without having to override all the read methods. The default implementation does nothing.
    Note this method is not called from skip(long) or reset(). You need to explicitly override those methods if you want to add post-processing steps also to them.
    
    Parameters:
    n - number of bytes read, or -1 if the end of stream was reached
    
    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

Class ProxyInputStream

Field Summary

Fields inherited from class java.io.FilterInputStream

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

ProxyInputStream

Method Detail

read

read

read

skip

available

close

mark

reset

markSupported

beforeRead

afterRead

handleIOException