in.thunk.camel.component.job.JobComponent.java Source code

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/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 in.thunk.camel.component.job;

import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.text.ParseException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.concurrent.atomic.AtomicInteger;

import org.apache.camel.CamelContext;
import org.apache.camel.StartupListener;
import org.apache.camel.impl.DefaultComponent;
import org.apache.camel.util.IntrospectionSupport;
import org.apache.camel.util.ObjectHelper;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.quartz.CronTrigger;
import org.quartz.JobDetail;
import org.quartz.Scheduler;
import org.quartz.SchedulerException;
import org.quartz.SchedulerFactory;
import org.quartz.SimpleTrigger;
import org.quartz.Trigger;
import org.quartz.impl.StdSchedulerFactory;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.util.StringUtils;

import com.google.common.collect.*;

/**
 * A <a href="http://camel.apache.org/quartz.html">Quartz Component</a>
 * <p/>
 * For a brief tutorial on setting cron expression see <a href=
 * "http://www.opensymphony.com/quartz/wikidocs/CronTriggers%20Tutorial.html"
 * >Quartz cron tutorial</a>.
 * 
 * @version $Revision:520964 $
 */
public class JobComponent extends DefaultComponent implements StartupListener {
    private static final transient Log LOG = LogFactory.getLog(JobComponent.class);
    private static final AtomicInteger JOBS = new AtomicInteger();
    private static Scheduler scheduler;
    private final List<JobToAdd> jobsToAdd = new ArrayList<JobToAdd>();
    private SchedulerFactory factory;
    private Properties properties;
    private String propertiesFile;
    private int startDelayedSeconds;
    private boolean autoStartScheduler = true;
    Multimap<JobKey, JobEndpoint> endpoints = HashMultimap.create();

    private final class JobToAdd {
        private final JobDetail job;
        private final Trigger trigger;

        private JobToAdd(JobDetail job, Trigger trigger) {
            this.job = job;
            this.trigger = trigger;
        }

        public JobDetail getJob() {
            return job;
        }

        public Trigger getTrigger() {
            return trigger;
        }
    }

    public JobComponent() {
    }

    public JobComponent(final CamelContext context) {
        super(context);
    }

    @Override
    protected JobEndpoint createEndpoint(final String uri, final String remaining,
            final Map<String, Object> parameters) throws Exception {

        // lets split the remaining into a group/name
        URI u = new URI(uri);
        String jobString = ObjectHelper.after(u.getPath(), "/");
        String group = u.getHost();

        String[] fragments = jobString.split("/");
        String name = fragments[0];
        String stepName = fragments.length > 1 ? fragments[1] : null;

        String expression = getAndRemoveParameter(parameters, "jobId", String.class);
        String cron = getAndRemoveParameter(parameters, "cron", String.class);
        Boolean fireNow = getAndRemoveParameter(parameters, "fireNow", Boolean.class, Boolean.FALSE);

        if (ObjectHelper.isEmpty(group) || ObjectHelper.isEmpty(name)) {
            throw new IllegalArgumentException("Cannot create a Job Endopoint without Group and Job Names");
        }

        Map<String, Object> triggerParameters = IntrospectionSupport.extractProperties(parameters, "trigger.");
        Map<String, Object> jobParameters = IntrospectionSupport.extractProperties(parameters, "job.");

        JobKey key = new JobKey(group, name, stepName);

        Collection<JobEndpoint> tasksEndpoints = endpoints.get(key);

        for (JobEndpoint jobEndpoint : tasksEndpoints) {
            if (uri.equals(jobEndpoint.getEndpointUri())) {

                if (!jobParameters.isEmpty()) {
                    if (jobEndpoint.isJobParamSet()) {
                        throw new IllegalArgumentException(
                                "Job parameters can be set only once for a specific job. Failing at uri " + uri);
                    }
                    setProperties(jobEndpoint.getJobDetail(), jobParameters);
                    jobEndpoint.setJobParamSet(true);
                }
                return jobEndpoint;
            }
        }

        JobEndpoint answer = new JobEndpoint(key, expression, this);
        tasksEndpoints.add(answer);

        answer.setStateful(true); //set it true by default, and the route definition can override
        setProperties(answer.getJobDetail(), jobParameters);

        if (!triggerParameters.isEmpty()) { // setting regular Quartz consumer with trigger and stuff

            Trigger trigger = null;

            // if we're starting up and not running in Quartz clustered mode
            // then check for a name conflict.
            if (!isClustered()) {
                // check to see if this trigger already exists
                trigger = getScheduler().getTrigger(name, group);
                if (trigger != null) {
                    String msg = "A Quartz job already exists with the name/group: " + name + "/" + group;
                    throw new IllegalArgumentException(msg);
                }
            }

            // create the trigger either cron or simple
            if (ObjectHelper.isNotEmpty(cron)) {
                trigger = createCronTrigger(cron);
            } else {
                trigger = new SimpleTrigger();
                if (fireNow) {
                    String intervalString = (String) triggerParameters.get("repeatInterval");
                    if (intervalString != null) {
                        long interval = Long.valueOf(intervalString);
                        trigger.setStartTime(new Date(System.currentTimeMillis() - interval));
                    }
                }
            }

            setProperties(trigger, triggerParameters);
            trigger.setName(name);
            trigger.setGroup(group);

            answer.addTrigger(trigger);
        }

        return answer;

    }

    protected CronTrigger createCronTrigger(String path) throws ParseException {
        // replace + back to space so it's a cron expression
        path = path.replaceAll("\\+", " ");
        CronTrigger cron = new CronTrigger();
        cron.setCronExpression(path);
        return cron;
    }

    public void onCamelContextStarted(CamelContext camelContext, boolean alreadyStarted) throws Exception {
        if (scheduler != null) {
            // register current camel context to scheduler so we can look it up
            // when jobs is being triggered
            scheduler.getContext().put(JobConstants.QUARTZ_CAMEL_CONTEXT + "-" + getCamelContext().getName(),
                    getCamelContext());
        }

        // if not configure to auto start then don't start it
        if (!isAutoStartScheduler()) {
            LOG.info("QuartzComponent configured to not auto start Quartz scheduler.");
            return;
        }

        // only start scheduler when CamelContext have finished starting
        startScheduler();
    }

    @Override
    protected void doStart() throws Exception {
        super.doStart();
        if (scheduler == null) {
            scheduler = getScheduler();
        }
    }

    @Override
    protected void doStop() throws Exception {
        super.doStop();

        if (scheduler != null) {
            int number = JOBS.get();
            if (number > 0) {
                LOG.info("Cannot shutdown Quartz scheduler: " + scheduler.getSchedulerName()
                        + " as there are still " + number + " jobs registered.");
            } else {
                // no more jobs then shutdown the scheduler
                LOG.info("There are no more jobs registered, so shutting down Quartz scheduler: "
                        + scheduler.getSchedulerName());
                scheduler.shutdown();
                scheduler = null;
            }
        }
    }

    public void addJob(JobDetail job, Trigger trigger) throws SchedulerException {
        if (scheduler == null) {
            // add job to internal list because we will defer adding to the
            // scheduler when camel context has been fully started
            jobsToAdd.add(new JobToAdd(job, trigger));
        } else {
            // add job directly to scheduler
            doAddJob(job, trigger);
        }
    }

    private void doAddJob(JobDetail job, Trigger trigger) throws SchedulerException {
        JOBS.incrementAndGet();

        Trigger existingTrigger = getScheduler().getTrigger(trigger.getName(), trigger.getGroup());
        if (existingTrigger == null) {
            if (LOG.isDebugEnabled()) {
                LOG.debug("Adding job using trigger: " + trigger.getGroup() + "/" + trigger.getName());
            }
            getScheduler().scheduleJob(job, trigger);
        } else if (hasTriggerChanged(existingTrigger, trigger)) {
            if (LOG.isDebugEnabled()) {
                LOG.debug("Trigger: " + trigger.getGroup() + "/" + trigger.getName()
                        + " already exists and will be updated by Quartz.");
            }
            scheduler.addJob(job, true);
            trigger.setJobName(job.getName());
            scheduler.rescheduleJob(trigger.getName(), trigger.getGroup(), trigger);
        } else {
            if (LOG.isDebugEnabled()) {
                LOG.debug("Trigger: " + trigger.getGroup() + "/" + trigger.getName()
                        + " already exists and will be resumed automatically by Quartz.");
            }
            if (!isClustered()) {
                scheduler.resumeTrigger(trigger.getName(), trigger.getGroup());
            }
        }
    }

    private boolean hasTriggerChanged(Trigger oldTrigger, Trigger newTrigger) {
        if (oldTrigger instanceof CronTrigger && oldTrigger.equals(newTrigger)) {
            CronTrigger oldCron = (CronTrigger) oldTrigger;
            CronTrigger newCron = (CronTrigger) newTrigger;
            return !oldCron.getCronExpression().equals(newCron.getCronExpression());
        } else {
            return !newTrigger.equals(oldTrigger);
        }
    }

    public void pauseJob(Trigger trigger) throws SchedulerException {
        JOBS.decrementAndGet();

        if (isClustered()) {
            // do not pause jobs which are clustered, as we want the jobs to
            // continue running on the other nodes
            if (LOG.isDebugEnabled()) {
                LOG.debug("Cannot pause job using trigger: " + trigger.getGroup() + "/" + trigger.getName()
                        + " as the JobStore is clustered.");
            }
        } else {
            if (LOG.isDebugEnabled()) {
                LOG.debug("Pausing job using trigger: " + trigger.getGroup() + "/" + trigger.getName());
            }
            getScheduler().pauseTrigger(trigger.getName(), trigger.getGroup());
            getScheduler().pauseJob(trigger.getName(), trigger.getGroup());
        }
    }

    public void deleteJob(String name, String group) throws SchedulerException {
        if (isClustered()) {
            // do not pause jobs which are clustered, as we want the jobs to
            // continue running on the other nodes
            if (LOG.isDebugEnabled()) {
                LOG.debug("Cannot delete job using trigger: " + group + "/" + name
                        + " as the JobStore is clustered.");
            }
        } else {
            Trigger trigger = getScheduler().getTrigger(name, group);
            if (trigger != null) {
                if (LOG.isDebugEnabled()) {
                    LOG.debug("Deleting job using trigger: " + group + "/" + name);
                }
                getScheduler().unscheduleJob(name, group);
            }
        }
    }

    /**
     * To force shutdown the quartz scheduler
     * 
     * @throws SchedulerException
     *             can be thrown if error shutting down
     */
    public void shutdownScheduler() throws SchedulerException {
        if (scheduler != null) {
            LOG.info("Forcing shutdown of Quartz scheduler: " + scheduler.getSchedulerName());
            scheduler.shutdown();
            scheduler = null;
        }
    }

    /**
     * Is the quartz scheduler clustered?
     */
    public boolean isClustered() throws SchedulerException {
        try {
            return getScheduler().getMetaData().isJobStoreClustered();
        } catch (NoSuchMethodError e) {
            LOG.debug("Job clustering is only supported since Quartz 1.7, isClustered returning false");
            return false;
        }
    }

    /**
     * To force starting the quartz scheduler
     * 
     * @throws SchedulerException
     *             can be thrown if error starting
     */
    public void startScheduler() throws SchedulerException {
        for (JobToAdd add : jobsToAdd) {
            doAddJob(add.getJob(), add.getTrigger());
        }
        jobsToAdd.clear();

        if (!getScheduler().isStarted()) {
            if (getStartDelayedSeconds() > 0) {
                LOG.info("Starting Quartz scheduler: " + getScheduler().getSchedulerName() + " delayed: "
                        + getStartDelayedSeconds() + " seconds.");
                try {
                    getScheduler().startDelayed(getStartDelayedSeconds());
                } catch (NoSuchMethodError e) {
                    LOG.warn("Your version of Quartz is too old to support delayed startup! "
                            + "Starting Quartz scheduler immediately : " + getScheduler().getSchedulerName());
                    getScheduler().start();
                }
            } else {
                LOG.info("Starting Quartz scheduler: " + getScheduler().getSchedulerName());
                getScheduler().start();
            }
        }
    }

    // Properties
    // -------------------------------------------------------------------------

    public SchedulerFactory getFactory() throws SchedulerException {
        if (factory == null) {
            factory = createSchedulerFactory();
        }
        return factory;
    }

    public void setFactory(final SchedulerFactory factory) {
        this.factory = factory;
    }

    public synchronized Scheduler getScheduler() throws SchedulerException {
        if (scheduler == null) {
            scheduler = createScheduler();
        }
        return scheduler;
    }

    public void setScheduler(final Scheduler scheduler) {
        JobComponent.scheduler = scheduler;
    }

    public Properties getProperties() {
        return properties;
    }

    public void setProperties(Properties properties) {
        this.properties = properties;
    }

    public String getPropertiesFile() {
        return propertiesFile;
    }

    public void setPropertiesFile(String propertiesFile) {
        this.propertiesFile = propertiesFile;
    }

    public int getStartDelayedSeconds() {
        return startDelayedSeconds;
    }

    public void setStartDelayedSeconds(int startDelayedSeconds) {
        this.startDelayedSeconds = startDelayedSeconds;
    }

    public boolean isAutoStartScheduler() {
        return autoStartScheduler;
    }

    public void setAutoStartScheduler(boolean autoStartScheduler) {
        this.autoStartScheduler = autoStartScheduler;
    }

    // Implementation methods
    // -------------------------------------------------------------------------

    protected Properties loadProperties() throws SchedulerException {
        Properties answer = getProperties();
        if (answer == null && getPropertiesFile() != null) {
            if (LOG.isInfoEnabled()) {
                LOG.info("Loading Quartz properties file from classpath: " + getPropertiesFile());
            }
            InputStream is = getCamelContext().getClassResolver().loadResourceAsStream(getPropertiesFile());
            if (is == null) {
                throw new SchedulerException(
                        "Quartz properties file not found in classpath: " + getPropertiesFile());
            }
            answer = new Properties();
            try {
                answer.load(is);
            } catch (IOException e) {
                throw new SchedulerException(
                        "Error loading Quartz properties file from classpath: " + getPropertiesFile(), e);
            }
        }
        return answer;
    }

    protected SchedulerFactory createSchedulerFactory() throws SchedulerException {
        Properties prop = loadProperties();
        if (prop != null) {
            if (LOG.isDebugEnabled()) {
                LOG.debug("Creating SchedulerFactory with properties: " + prop);
            }
            return new StdSchedulerFactory(prop);
        } else {
            return new StdSchedulerFactory();
        }
    }

    protected Scheduler createScheduler() throws SchedulerException {
        Scheduler scheduler = getFactory().getScheduler();
        // register current camel context to scheduler so we can look it up when
        // jobs is being triggered
        scheduler.getContext().put(JobConstants.QUARTZ_CAMEL_CONTEXT + "-" + getCamelContext().getName(),
                getCamelContext());
        return scheduler;
    }
}