Filter

extends Object

java.lang.Object
↳	com.sun.net.httpserver.Filter

Known Direct Subclasses

AuthFilter

Class Overview

A filter used to pre- and post-process incoming requests. Pre-processing occurs before the application's exchange handler is invoked, and post-processing occurs after the exchange handler returns. Filters are organised in chains, and are associated with HttpContext instances.

Each Filter in the chain, invokes the next filter within its own doFilter() implementation. The final Filter in the chain invokes the applications exchange handler.

Summary

Nested Classes
class	Filter.Chain	a chain of filters associated with a HttpServer.

Protected Constructors
	Filter()

Public Methods
abstract String	description() returns a short description of this Filter
abstract void	doFilter(HttpExchange exchange, Filter.Chain chain) Asks this filter to pre/post-process the given exchange.

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Inherited Methods

From class java.lang.Object

Object	clone() Creates and returns a copy of this object.
boolean	equals(Object obj) Indicates whether some other object is "equal to" this one.
void	finalize() Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
final Class<?>	getClass() Returns the runtime class of this `Object`.
int	hashCode() Returns a hash code value for the object.
final void	notify() Wakes up a single thread that is waiting on this object's monitor.
final void	notifyAll() Wakes up all threads that are waiting on this object's monitor.
String	toString() Returns a string representation of the object.
final void	wait() Causes the current thread to wait until another thread invokes the `notify()` method or the `notifyAll()` method for this object.
final void	wait(long timeout, int nanos) Causes the current thread to wait until another thread invokes the `notify()` method or the `notifyAll()` method for this object, or some other thread interrupts the current thread, or a certain amount of real time has elapsed.
final void	wait(long timeout) Causes the current thread to wait until either another thread invokes the `notify()` method or the `notifyAll()` method for this object, or a specified amount of time has elapsed.

Protected Constructors

protected Filter ()

Public Methods

public abstract String description ()

returns a short description of this Filter

Returns

a string describing the Filter

public abstract void doFilter (HttpExchange exchange, Filter.Chain chain)

Asks this filter to pre/post-process the given exchange. The filter can :-

examine or modify the request headers
filter the request body or the response body, by creating suitable filter streams and calling setStreams(InputStream, OutputStream)
set attribute Objects in the exchange, which other filters or the exchange handler can access.
decide to either :-
1. invoke the next filter in the chain, by calling doFilter(HttpExchange)
2. terminate the chain of invocation, by not calling doFilter(HttpExchange)
if option 1. above taken, then when doFilter() returns all subsequent filters in the Chain have been called, and the response headers can be examined or modified.
if option 2. above taken, then this Filter must use the HttpExchange to send back an appropriate response

Parameters

exchange	the `HttpExchange` to be filtered.
chain	the Chain which allows the next filter to be invoked.

Throws

IOException	may be thrown by any filter module, and if caught, must be rethrown again.
NullPointerException	if either exchange or chain are `null`

Interfaces

Classes