/*
* JBoss, Home of Professional Open Source
* Copyright 2010, Red Hat Middleware LLC, and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jboss.arquillian.impl.core;
import java.lang.annotation.Annotation;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Type;
import org.jboss.arquillian.impl.core.spi.InvocationException;
import org.jboss.arquillian.impl.core.spi.Manager;
import org.jboss.arquillian.impl.core.spi.ObserverMethod;
import org.jboss.arquillian.spi.core.annotation.Observes;
/**
* ObjectObserver
*
* @author <a href="mailto:aslak@redhat.com">Aslak Knutsen</a>
* @version $Revision: $
*/
public class ObserverImpl implements ObserverMethod, Comparable<ObserverMethod>
{
private Object target;
private Method method;
//-------------------------------------------------------------------------------------||
// Public Factory Methods -------------------------------------------------------------||
//-------------------------------------------------------------------------------------||
public static ObserverImpl of(Object extension, Method observerMethod)
{
return new ObserverImpl(extension, observerMethod);
}
ObserverImpl(Object target, Method method)
{
this.target = target;
this.method = method;
}
//-------------------------------------------------------------------------------------||
// Required Implementations - ObserverMethod ------------------------------------------||
//-------------------------------------------------------------------------------------||
/* (non-Javadoc)
* @see org.jboss.arquillian.api.Typed#getType()
*/
@Override
public Type getType()
{
return method.getGenericParameterTypes()[0];
}
/**
* @return the method
*/
@Override
public Method getMethod()
{
return method;
}
/* (non-Javadoc)
* @see org.jboss.arquillian.api.ObserverMethod#invoke(java.lang.Object)
*/
@Override
public boolean invoke(Manager manager, Object event)
{
try
{
Object[] arguments = resolveArguments(manager, event);
if(containsNull(arguments))
{
return false;
}
method.invoke(target, arguments);
return true;
}
catch (Exception e)
{
if(e instanceof InvocationTargetException)
{
Throwable cause = ((InvocationTargetException)e).getTargetException();
// Exception already wrapped by another Observer down the chain.
if(cause instanceof InvocationException)
{
throw (InvocationException)cause;
}
throw new InvocationException(cause);
}
throw new InvocationException(e);
}
}
/* (non-Javadoc)
* @see java.lang.Comparable#compareTo(java.lang.Object)
*/
@Override
public int compareTo(ObserverMethod o)
{
if(o == null)
{
return 1;
}
Integer a = getPresedence(getMethod());
Integer b = getPresedence(o.getMethod());
return b.compareTo(a);
}
private Integer getPresedence(Method method)
{
for(Annotation[] annotations : method.getParameterAnnotations())
{
for(Annotation annotation : annotations)
{
if(annotation.annotationType() == Observes.class)
{
return ((Observes)annotation).precedence();
}
}
}
return 0;
}
/**
* Resolve all Observer method arguments. Unresolved argument types wil be null.
*
* @param manager
* @param event
* @return
*/
private Object[] resolveArguments(Manager manager, Object event)
{
Class<?>[] argumentTypes = getMethod().getParameterTypes();
int numberOfArguments = argumentTypes.length;;
// we know that the first Argument is always the Event, and it will be there else this wouldn't be a Observer method
Object[] arguments = new Object[numberOfArguments];
arguments[0] = event;
for(int i = 1; i < numberOfArguments; i++)
{
Class<?> argumentType = argumentTypes[i];
arguments[i] = manager.resolve(argumentType);
}
return arguments;
}
/**
* Check that all arguments were resolved. Do not invoke if not.
*
* @param arguments
* @return
*/
private boolean containsNull(Object[] arguments)
{
for(Object argument : arguments)
{
if(argument == null)
{
return true;
}
}
return false;
}
}