org.apache.tuscany.core.wire
Class InvocationConfiguration

java.lang.Object
  org.apache.tuscany.core.wire.InvocationConfiguration

Direct Known Subclasses:

SourceInvocationConfiguration, TargetInvocationConfiguration

public abstract class InvocationConfiguration
extends java.lang.Object

Contains a source- or target-side invocation pipeline for a service operation. The runtime framework creates invocation chains on a per-operation, per-service basis. Further, invocation chains are further distinguished by being part of the source or target sides of a wire. Chains are "bridged" together by the runtime by a set of WireBuilders with the source-side holding references to the target.

InvocationChains are managed by WireConfigurations, which are used by WireFactorys to buildSource wires and proxies.

Invocation configurations must contain at least one interceptor and may have 0 to N handlers. Handlers process a wire request or response in a one-way fashion. A typical wire sequence where interceptors and handlers are configured for both the source and target-side will proceed as follows:

 

 
The first source interceptor will be called with a message, which will in
     turn invoke the next interceptor in the chain 
The last source interceptor, which must be of type RequestResponseInterceptor if there are handlers present, will be invoked. The RR
     interceptor will in turn pass the message to a MessageChannel which will invoke all source-side request handlers.
 
The RR interceptor will then invoke the target-side request MessageChannel.
 
The last source-side handler, an instance of MessageDispatcher, will invoke the
     first source-side interceptor, which in turn will pass the message down the target-side interceptor chain.
 
If the target is a component instance the last target-side interceptor, an instance of
     InvokerInterceptor will retrieve the TargetInvoker from the message and
     call it to invoke the operation on a target instance. TargetInvokers are help by
     the source proxy to enable optimizations such as caching of target instances. 
 The response is returned up the wire
 stack
     until it reaches the source-side RequestResponseInterceptor, which invokes the target and source-side response
     channels respectively.
 
The response is then passed back up the rest of the wire stack. 
 

The source-to-target bridge may be constructed in any of the following ways:

 

 
Source handler-to-target handler
 
Source handler-to-target interceptor
 
Source interceptor-to-target handler
 
Source interceptor-to-target interceptor
 
 

In some scenarios, a service proxy may only contain target-side invocaton chains, for example, when a service is resolved through a locate operation by a non-component client. In this case, there will be no source-side wire chains and the target invoker will be held by the target-side and passed down the pipeline.

Version:

$Rev: 396284 $ $Date: 2006-04-23 11:27:42 -0400 (Sun, 23 Apr 2006) $

See Also:

WireBuilder, WireFactory, TargetInvoker, MessageDispatcher

Field Summary

protected Interceptor	interceptorChainHead
protected Interceptor	interceptorChainTail
protected java.lang.reflect.Method	operation
protected java.util.List<MessageHandler>	requestHandlers
protected java.util.List<MessageHandler>	responseHandlers
protected TargetInvoker	targetInvoker

Constructor Summary

InvocationConfiguration(java.lang.reflect.Method operation)

Method Summary

void	addInterceptor(Interceptor interceptor) Adds an interceptor to the chain
void	addRequestHandler(MessageHandler handler) Adds an request handler to the invocation chain
void	addResponseHandler(MessageHandler handler) Adds an response handler to the invocation chain
abstract void	build() Signals to the chain that its configuration is complete.
Interceptor	getHeadInterceptor() Returns the first interceptor in the chain
java.lang.reflect.Method	getMethod() Returns the target operation for this invocation chain
java.util.List<MessageHandler>	getRequestHandlers() Returns the request handler chain
java.util.List<MessageHandler>	getResponseHandlers() Returns the response handler chain
Interceptor	getTailInterceptor() Returns the last interceptor in the chain
TargetInvoker	getTargetInvoker() Returns the target invoker that is passed down the chain
void	setTargetInvoker(TargetInvoker invoker) Sets the target invoker to pass down the chain

Methods inherited from class java.lang.Object

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

Field Detail

operation

protected java.lang.reflect.Method operation

targetInvoker

protected TargetInvoker targetInvoker

interceptorChainHead

protected Interceptor interceptorChainHead

interceptorChainTail

protected Interceptor interceptorChainTail

requestHandlers

protected java.util.List<MessageHandler> requestHandlers

responseHandlers

protected java.util.List<MessageHandler> responseHandlers

Constructor Detail

InvocationConfiguration

public InvocationConfiguration(java.lang.reflect.Method operation)

Method Detail

getMethod

public java.lang.reflect.Method getMethod()

Returns the target operation for this invocation chain

addRequestHandler

public void addRequestHandler(MessageHandler handler)

Adds an request handler to the invocation chain

addResponseHandler

public void addResponseHandler(MessageHandler handler)

Adds an response handler to the invocation chain

getRequestHandlers

public java.util.List<MessageHandler> getRequestHandlers()

Returns the request handler chain

getResponseHandlers

public java.util.List<MessageHandler> getResponseHandlers()

Returns the response handler chain

setTargetInvoker

public void setTargetInvoker(TargetInvoker invoker)

Sets the target invoker to pass down the chain

getTargetInvoker

public TargetInvoker getTargetInvoker()

Returns the target invoker that is passed down the chain

addInterceptor

public void addInterceptor(Interceptor interceptor)

Adds an interceptor to the chain

getTailInterceptor

public Interceptor getTailInterceptor()

Returns the last interceptor in the chain

getHeadInterceptor

public Interceptor getHeadInterceptor()

Returns the first interceptor in the chain

build

public abstract void build()

Signals to the chain that its configuration is complete. Implementations may use this callback to prepare there invocation chains.