de.codecentric.batch.listener.RunningExecutionTrackerListener.java Source code

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Here is the source code for de.codecentric.batch.listener.RunningExecutionTrackerListener.java

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/*
 * Copyright 2014 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 de.codecentric.batch.listener;

import org.springframework.batch.core.JobExecution;
import org.springframework.batch.core.JobExecutionListener;

import de.codecentric.batch.monitoring.RunningExecutionTracker;

/**
 * This listener is needed for tracking the running JobExecutions on this server.
 *  
 * <p>It's easy to find out which jobs are running in general by looking into the database, but it has 
 * some drawbacks:
 * <ul>
 * <li>Data in the database might be corrupted. A job may be in status STARTED simply because someone
 * killed the process and Spring Batch didn't have the chance to update the status.</li>
 * <li>We cannot tell from the database on which server the job is running.</li>
 * <li>We might just use an in-memory database, then we cannot access it.</li>
 * </ul>
 *  
 * <p>This listener uses the {@link RunningExecutionTracker} to keep this information in memory and 
 * accessible for the http endpoints.
 * 
 * @author Tobias Flohre
 *
 */
public class RunningExecutionTrackerListener implements JobExecutionListener {

    private RunningExecutionTracker runningExecutionTracker;

    public RunningExecutionTrackerListener(RunningExecutionTracker runningExecutionTracker) {
        super();
        this.runningExecutionTracker = runningExecutionTracker;
    }

    @Override
    public void beforeJob(JobExecution jobExecution) {
        runningExecutionTracker.addRunningExecution(jobExecution.getJobInstance().getJobName(),
                jobExecution.getId());
    }

    @Override
    public void afterJob(JobExecution jobExecution) {
        runningExecutionTracker.removeRunningExecution(jobExecution.getId());
    }

}