Package org.forgerock.openig.handler

Class DispatchHandler

java.lang.Object

org.forgerock.openig.handler.DispatchHandler

All Implemented Interfaces:

Handler

public class DispatchHandler
extends Object
implements Handler

Dispatches to one of a list of handlers. When a request is handled, each handler's condition is evaluated. If a condition expression yields true, then the request is dispatched to the associated handler with no further processing.

If no condition yields true then the handler will return a 404 not found response. Therefore, it's advisable to have a single "default" handler at the end of the list with no condition (unconditional) to handle otherwise un-dispatched requests.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	DispatchHandler.Heaplet	Creates and initializes a dispatch handler in a heap environment.

Constructor Summary

Constructors

Constructor	Description
DispatchHandler()

Method Summary

Modifier and Type	Method	Description
DispatchHandler	addBinding(Expression<Boolean> condition, Handler handler, Expression<String> baseURI)	Binds an expression to the current handler to dispatch to.
DispatchHandler	addUnconditionalBinding(Handler handler, Expression<String> baseURI)	Adds an unconditional bindings to the handler.
Promise<Response,NeverThrowsException>	handle(Context context, Request request)	Returns a Promise representing the asynchronous Response of the given request.

Methods inherited from class java.lang.Object

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

Constructor Detail

DispatchHandler

public DispatchHandler()

Method Detail

addBinding

public DispatchHandler addBinding(Expression<Boolean> condition,
                                  Handler handler,
                                  Expression<String> baseURI)

Binds an expression to the current handler to dispatch to.

Parameters:

condition - Condition to evaluate to determine if associated handler should be dispatched to. If omitted, then dispatch is unconditional.

handler - The name of the handler heap object to dispatch to if the associated condition yields true.

baseURI - Overrides the existing request URI, making requests relative to a new base URI. Only scheme, host and port are used in the supplied URI. Default: leave URI untouched.

Returns:

The current dispatch handler.

addUnconditionalBinding

public DispatchHandler addUnconditionalBinding(Handler handler,
                                               Expression<String> baseURI)

Adds an unconditional bindings to the handler.

Parameters:

handler - The name of the handler heap object to dispatch to if the associated condition yields true.

baseURI - Overrides the existing request URI, making requests relative to a new base URI. Only scheme, host and port are used in the supplied URI. Default: leave URI untouched.

Returns:

The current dispatch handler.

handle

public Promise<Response,NeverThrowsException> handle(Context context,
                                                           Request request)

Description copied from interface: Handler

Returns a Promise representing the asynchronous Response of the given request. If any (asynchronous) processing goes wrong, the promise still contains a Response (probably from the 4xx or 5xx status code family).

A handler that doesn't hand-off the processing to another downstream handler is responsible for creating the response.

The returned Promise contains the response returned from the server as-is. This is responsibility of the handler to produce the appropriate error response (404, 500, ...) in case of processing error.

Note: As of Promise 2.0 implementation, it is not permitted to throw any runtime exception here. Doing so produce unexpected behaviour (most likely a server-side hang of the processing thread).

Specified by:

handle in interface Handler

Parameters:

context - The request context.

request - The request.

Returns:

A Promise representing the response to be returned to the caller.