/*
* Copyright 2015 the original author or authors.
*
* 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.springframework.statemachine.support;
import java.util.Collection;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;
import org.springframework.messaging.Message;
import org.springframework.statemachine.StateContext;
import org.springframework.statemachine.StateMachine;
import org.springframework.statemachine.state.State;
import org.springframework.statemachine.transition.Transition;
/**
* Support class working with a {@link StateMachineInterceptor}s.
*
* @author Janne Valkealahti
*
* @param <S> the type of state
* @param <E> the type of event
*/
public class StateMachineInterceptorList<S, E> {
private final List<StateMachineInterceptor<S, E>> interceptors = new CopyOnWriteArrayList<StateMachineInterceptor<S, E>>();
/**
* Sets the interceptors, clears any existing interceptors.
*
* @param interceptors the list of interceptors
* @return <tt>true</tt> if interceptor list changed as a result of the
* call
*/
public boolean set(List<StateMachineInterceptor<S, E>> interceptors) {
synchronized (this.interceptors) {
this.interceptors.clear();
return this.interceptors.addAll(interceptors);
}
}
/**
* Adds interceptor to the list.
*
* @param interceptor the interceptor
* @return <tt>true</tt> (as specified by {@link Collection#add})
*/
public boolean add(StateMachineInterceptor<S, E> interceptor) {
return interceptors.add(interceptor);
}
/**
* Removes interceptor from the list.
*
* @param interceptor the interceptor
* @return <tt>true</tt> (as specified by {@link Collection#remove})
*/
public boolean remove(StateMachineInterceptor<S, E> interceptor) {
return interceptors.remove(interceptor);
}
/**
* Pre event.
*
* @param message the message
* @param stateMachine the state machine
* @return the message
*/
public Message<E> preEvent(Message<E> message, StateMachine<S, E> stateMachine) {
for (StateMachineInterceptor<S, E> interceptor : interceptors) {
if ((message = interceptor.preEvent(message, stateMachine)) == null) {
break;
}
}
return message;
}
/**
* Pre state change.
*
* @param state the state
* @param message the message
* @param transition the transition
* @param stateMachine the state machine
*/
public void preStateChange(State<S, E> state, Message<E> message, Transition<S, E> transition,
StateMachine<S, E> stateMachine) {
for (StateMachineInterceptor<S, E> interceptor : interceptors) {
interceptor.preStateChange(state, message, transition, stateMachine);
}
}
/**
* Post state change.
*
* @param state the state
* @param message the message
* @param transition the transition
* @param stateMachine the state machine
*/
public void postStateChange(State<S, E> state, Message<E> message, Transition<S, E> transition,
StateMachine<S, E> stateMachine) {
for (StateMachineInterceptor<S, E> interceptor : interceptors) {
interceptor.postStateChange(state, message, transition, stateMachine);
}
}
/**
* Pre transition.
*
* @param stateContext the state context
* @return the state context
*/
public StateContext<S, E> preTransition(StateContext<S, E> stateContext) {
for (StateMachineInterceptor<S, E> interceptor : interceptors) {
if ((stateContext = interceptor.preTransition(stateContext)) == null) {
break;
}
}
return stateContext;
}
/**
* Post transition.
*
* @param stateContext the state context
* @return the state context
*/
public StateContext<S, E> postTransition(StateContext<S, E> stateContext) {
for (StateMachineInterceptor<S, E> interceptor : interceptors) {
if ((stateContext = interceptor.postTransition(stateContext)) == null) {
break;
}
}
return stateContext;
}
/**
* State machine error.
*
* @param stateMachine the state machine
* @param exception the exception
* @return the exception
*/
public Exception stateMachineError(StateMachine<S, E> stateMachine, Exception exception) {
for (StateMachineInterceptor<S, E> interceptor : interceptors) {
if ((exception = interceptor.stateMachineError(stateMachine, exception)) == null) {
break;
}
}
return exception;
}
@Override
public String toString() {
return "StateMachineInterceptorList [interceptors=" + interceptors + "]";
}
}