com.jacob.com
Class InvocationProxy

java.lang.Object
  com.jacob.com.InvocationProxy

Direct Known Subclasses:

ActiveXInvocationProxy, InvocationProxyAllVariants

public abstract class InvocationProxy
extends Object

Version:

$Id$

Author:

joe DispatchEvents wraps this class around any event handlers before making the JNI call that sets up the link with EventProxy. This means that EventProxy.cpp just calls invoke(String,Variant[]) against the instance of this class. Then this class does reflection against the event listener to call the actual event methods. The event methods can return void or return a Variant. Any value returned will be passed back to the calling windows module by the Jacob JNI layer.

The void returning signature is the standard legacy signature. The Variant returning signature was added in 1.10 to support event handlers returning values.

Field Summary

protected Object

mTargetObject the object we will try and forward to.

Constructor Summary

protected

InvocationProxy() dummy constructor for subclasses that don't actually wrap anything and just want to override the invoke() method

Method Summary

Variant	getVariant() used by EventProxy.cpp to create variant objects in the right thread
abstract Variant	invoke(String methodName, Variant[] targetParameters) The method actually invoked by EventProxy.cpp.
void	setTarget(Object pTargetObject) Sets the target for this InvocationProxy.

Methods inherited from class java.lang.Object

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

Field Detail

mTargetObject

protected Object mTargetObject

the object we will try and forward to.

Constructor Detail

InvocationProxy

protected InvocationProxy()

dummy constructor for subclasses that don't actually wrap anything and just want to override the invoke() method

Method Detail

invoke

public abstract Variant invoke(String methodName,
                               Variant[] targetParameters)

The method actually invoked by EventProxy.cpp. The method name is calculated by the underlying JNI code from the MS windows Callback function name. The method is assumed to take an array of Variant objects. The method may return a Variant or be a void. Those are the only two options that will not blow up.

Subclasses that override this should make sure mTargetObject is not null before processing.

Parameters:

methodName - name of method in mTargetObject we will invoke

targetParameters - Variant[] that is the single parameter to the method

Returns:

an object that will be returned to the com event caller

getVariant

public Variant getVariant()

used by EventProxy.cpp to create variant objects in the right thread

Returns:

Variant object that will be used by the COM layer

setTarget

public void setTarget(Object pTargetObject)

Sets the target for this InvocationProxy.

Parameters:

pTargetObject -

Throws:

IllegalArgumentException - if target is not publicly accessible