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/*
* Copyright (c) 2012, Jan Bernitt
*
* Licensed under the Apache License, Version 2.0, http://www.apache.org/licenses/LICENSE-2.0
*/
package se.jbee.inject.service;
import se.jbee.inject.Type;
import se.jbee.inject.util.Value;
/**
* Frames the invocation of {@link ServiceMethod}s with further functionality that can be executed
* {@link #before(Value, Type)} or {@link #after(Value, Value, Object)} the invoked
* {@linkplain ServiceMethod}. Thereby a state can be passed between these tow methods. The result
* of first will be passed to the second as an argument. This allows them stay stateless.
*
* A {@link ServiceInvocation} intentionally doesn't give any control or access over/to the invoked
* {@linkplain ServiceMethod} in order to be able to grant the same actual function invocation even
* with faulty {@linkplain ServiceInvocation}s in place. That includes catching all exceptions
* thrown in {@link #before(Value, Type)} or {@link #after(Value, Value, Object)}.
*
* @author Jan Bernitt ([email protected])
*
* @param
* Type of the state transfered between {@link #before(Value, Type)} and
* {@link #after(Value, Value, Object)}.
*/
public interface ServiceInvocation {
T before( Value parameter, Type result );
void after( Value parameter, Value result, T before );
void afterException( Value parameter, Type result, Exception e, T before );
/**
* Used to hook up a {@link ServiceInvocation} to {@link ServiceMethod}s.
*
* When targeting is used for the extension it has to be chosen which of the 4 possible types
* the targeting is applied to.
*
*/
enum ServiceInvocationExtension
implements Extension> {
/**
* The {@link Class} defined the method that becomes the injected {@link ServiceMethod}.
*/
DEFINING_TYPE,
/**
* The {@link Class} (whose method) is receiving the injected {@link ServiceMethod}.
*/
INJECTED_TYPE,
/**
* The {@link Type} of the {@link ServiceMethod}'s parameter generic.
*/
PARAMETER_TYPE,
/**
* The {@link Type} of the {@link ServiceMethod}'s return type generic.
*/
RETURN_TYPE
}
}