org.springframework.statemachine.transition.AbstractTransition.java Source code

Introduction

Here is the source code for org.springframework.statemachine.transition.AbstractTransition.java

Source

/*
 * 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.transition;

import java.util.Collection;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.statemachine.StateContext;
import org.springframework.statemachine.action.Action;
import org.springframework.statemachine.action.ActionListener;
import org.springframework.statemachine.action.CompositeActionListener;
import org.springframework.statemachine.guard.Guard;
import org.springframework.statemachine.security.SecurityRule;
import org.springframework.statemachine.state.State;
import org.springframework.statemachine.trigger.Trigger;
import org.springframework.util.Assert;

/**
 * Base implementation of a {@link Transition}.
 *
 * @author Janne Valkealahti
 *
 * @param <S> the type of state
 * @param <E> the type of event
 */
public abstract class AbstractTransition<S, E> implements Transition<S, E> {

    private final static Log log = LogFactory.getLog(AbstractTransition.class);
    protected final State<S, E> target;
    protected final Collection<Action<S, E>> actions;
    private final State<S, E> source;
    private final TransitionKind kind;
    private final Guard<S, E> guard;
    private final Trigger<S, E> trigger;
    private final SecurityRule securityRule;
    private CompositeActionListener<S, E> actionListener;

    /**
     * Instantiates a new abstract transition.
     *
     * @param source the source
     * @param target the target
     * @param actions the actions
     * @param event the event
     * @param kind the kind
     * @param guard the guard
     * @param trigger the trigger
     */
    public AbstractTransition(State<S, E> source, State<S, E> target, Collection<Action<S, E>> actions, E event,
            TransitionKind kind, Guard<S, E> guard, Trigger<S, E> trigger) {
        this(source, target, actions, event, kind, guard, trigger, null);
    }

    /**
     * Instantiates a new abstract transition.
     *
     * @param source the source
     * @param target the target
     * @param actions the actions
     * @param event the event
     * @param kind the kind
     * @param guard the guard
     * @param trigger the trigger
     * @param securityRule the security rule
     */
    public AbstractTransition(State<S, E> source, State<S, E> target, Collection<Action<S, E>> actions, E event,
            TransitionKind kind, Guard<S, E> guard, Trigger<S, E> trigger, SecurityRule securityRule) {
        Assert.notNull(kind, "Transition type must be set");
        this.source = source;
        this.target = target;
        this.actions = actions;
        this.kind = kind;
        this.guard = guard;
        this.trigger = trigger;
        this.securityRule = securityRule;
    }

    @Override
    public State<S, E> getSource() {
        return source;
    }

    @Override
    public Trigger<S, E> getTrigger() {
        return trigger;
    }

    @Override
    public boolean transit(StateContext<S, E> context) {
        if (guard != null) {
            try {
                if (!guard.evaluate(context)) {
                    return false;
                }
            } catch (Throwable t) {
                log.warn("Deny guard due to throw as GUARD should not error", t);
                return false;
            }
        }
        executeAllActions(context);
        return true;
    }

    @Override
    public TransitionKind getKind() {
        return kind;
    }

    @Override
    public SecurityRule getSecurityRule() {
        return securityRule;
    }

    @Override
    public State<S, E> getTarget() {
        return target;
    }

    @Override
    public Collection<Action<S, E>> getActions() {
        return actions;
    }

    @Override
    public void addActionListener(ActionListener<S, E> listener) {
        synchronized (this) {
            if (this.actionListener == null) {
                this.actionListener = new CompositeActionListener<>();
            }
            this.actionListener.register(listener);
        }
    }

    @Override
    public void removeActionListener(ActionListener<S, E> listener) {
        synchronized (this) {
            if (this.actionListener != null) {
                this.actionListener.unregister(listener);
            }
        }
    }

    protected final void executeAllActions(StateContext<S, E> context) {
        if (actions == null) {
            return;
        }

        for (Action<S, E> action : actions) {
            long now = System.currentTimeMillis();
            action.execute(context);
            if (this.actionListener != null) {
                this.actionListener.onExecute(context.getStateMachine(), action, System.currentTimeMillis() - now);
            }
        }
    }
}