org.arrow.model.task.impl.ServiceTask.java Source code

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Here is the source code for org.arrow.model.task.impl.ServiceTask.java

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/*
 * Copyright 2014 Christian Weber
 *
 * 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.arrow.model.task.impl;

import org.arrow.model.task.AbstractTask;
import org.arrow.runtime.api.task.JavaDelegate;
import org.arrow.runtime.execution.Execution;
import org.arrow.runtime.execution.service.ExecutionService;
import org.arrow.runtime.message.EventMessage;
import org.arrow.util.FutureUtil;
import org.springframework.data.annotation.TypeAlias;
import org.springframework.data.neo4j.annotation.NodeEntity;
import org.springframework.util.StringUtils;
import scala.concurrent.Future;

/**
 * BPMN 2 Service Task implementation used to execute Java methods.
 * 
 * @author christian.weber
 * @since 1.0.0
 */
@NodeEntity
@TypeAlias("ServiceTask")
public class ServiceTask extends AbstractTask {

    private String serviceClass;
    private String expression;
    private String beanName;

    /**
     * {@inheritDoc}
     */
    @Override
    public Future<Iterable<EventMessage>> executeTask(Execution execution, ExecutionService service) {

        try {
            // spring bean name delegate
            if (!StringUtils.isEmpty(beanName)) {
                JavaDelegate javaDelegate = service.getJavaDelegateByName(beanName);
                return javaDelegate.execute(execution);
            }

            // spring expression delegate
            if (!StringUtils.isEmpty(expression)) {
                Object result = service.evaluateExpression(expression);
                return tryCast(result);
            }

            // class delegate
            if (!StringUtils.isEmpty(serviceClass)) {
                JavaDelegate javaDelegate = service.getJavaDelegateByClassName(serviceClass);
                return javaDelegate.execute(execution);
            }

            return FutureUtil.result();
        } finally {
            // mark the task as finished
            finish(execution, service);
        }
    }

    /**
     * Tries to cast the given object to a future result of iterable event messages.
     * If the object cannot be cast a fallback future is returned.
     *
     * @param result the object to cast
     * @return Future
     */
    @SuppressWarnings("unchecked")
    private Future<Iterable<EventMessage>> tryCast(Object result) {
        if (!(result instanceof Future))
            return FutureUtil.result();

        try {
            return (Future<Iterable<EventMessage>>) result;
        } catch (ClassCastException ignored) {
            return FutureUtil.result();
        }
    }

    @SuppressWarnings("unused")
    public String getServiceClass() {
        return serviceClass;
    }

    public void setServiceClass(String serviceClass) {
        this.serviceClass = serviceClass;
    }

    public String getExpression() {
        return expression;
    }

    public void setExpression(String expression) {
        this.expression = expression;
    }

    public String getBeanName() {
        return beanName;
    }

    public void setBeanName(String beanName) {
        this.beanName = beanName;
    }
}