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Quartz Enterprise Job Scheduler - additional library of ready to use Jobs
/*
* Copyright 2001-2009 Terracotta, Inc.
*
* 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.quartz.jobs;
import java.io.File;
import java.io.FileFilter;
import org.quartz.DisallowConcurrentExecution;
import org.quartz.Job;
import org.quartz.JobDataMap;
import org.quartz.JobExecutionContext;
import org.quartz.JobExecutionException;
import org.quartz.PersistJobDataAfterExecution;
import org.quartz.SchedulerContext;
import org.quartz.SchedulerException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Inspects a directory and compares whether any files' "last modified dates"
* have changed since the last time it was inspected. If one or more files
* have been updated (or created), the job invokes a "call-back" method on an
* identified DirectoryScanListener that can be found in the
* SchedulerContext.
*
* @author pl47ypus
* @author jhouse
* @see org.quartz.jobs.DirectoryScanListener
* @see org.quartz.SchedulerContext
*/
@DisallowConcurrentExecution
@PersistJobDataAfterExecution
public class DirectoryScanJob implements Job {
/**
* JobDataMap key with which to specify the directory to be
* monitored - an absolute path is recommended.
*/
public static final String DIRECTORY_NAME = "DIRECTORY_NAME";
/**
* JobDataMap key with which to specify the
* {@link org.quartz.jobs.DirectoryScanListener} to be
* notified when the directory contents change.
*/
public static final String DIRECTORY_SCAN_LISTENER_NAME = "DIRECTORY_SCAN_LISTENER_NAME";
/**
* JobDataMap key with which to specify a long
* value that represents the minimum number of milliseconds that must have
* past since the file's last modified time in order to consider the file
* new/altered. This is necessary because another process may still be
* in the middle of writing to the file when the scan occurs, and the
* file may therefore not yet be ready for processing.
*
* If this parameter is not specified, a default value of
* 5000 (five seconds) will be used.
*/
public static final String MINIMUM_UPDATE_AGE = "MINIMUM_UPDATE_AGE";
private static final String LAST_MODIFIED_TIME = "LAST_MODIFIED_TIME";
private final Logger log = LoggerFactory.getLogger(getClass());
public DirectoryScanJob() {
}
/**
* @see org.quartz.Job#execute(org.quartz.JobExecutionContext)
*/
public void execute(JobExecutionContext context) throws JobExecutionException {
JobDataMap mergedJobDataMap = context.getMergedJobDataMap();
SchedulerContext schedCtxt = null;
try {
schedCtxt = context.getScheduler().getContext();
} catch (SchedulerException e) {
throw new JobExecutionException("Error obtaining scheduler context.", e, false);
}
String dirName = mergedJobDataMap.getString(DIRECTORY_NAME);
String listenerName = mergedJobDataMap.getString(DIRECTORY_SCAN_LISTENER_NAME);
if(dirName == null) {
throw new JobExecutionException("Required parameter '" +
DIRECTORY_NAME + "' not found in merged JobDataMap");
}
if(listenerName == null) {
throw new JobExecutionException("Required parameter '" +
DIRECTORY_SCAN_LISTENER_NAME + "' not found in merged JobDataMap");
}
DirectoryScanListener listener = (DirectoryScanListener)schedCtxt.get(listenerName);
if(listener == null) {
throw new JobExecutionException("DirectoryScanListener named '" +
listenerName + "' not found in SchedulerContext");
}
long lastDate = -1;
if(mergedJobDataMap.containsKey(LAST_MODIFIED_TIME)) {
lastDate = mergedJobDataMap.getLong(LAST_MODIFIED_TIME);
}
long minAge = 5000;
if(mergedJobDataMap.containsKey(MINIMUM_UPDATE_AGE)) {
minAge = mergedJobDataMap.getLong(MINIMUM_UPDATE_AGE);
}
long maxAgeDate = System.currentTimeMillis() - minAge;
File[] updatedFiles = getUpdatedOrNewFiles(dirName, lastDate, maxAgeDate);
if(updatedFiles == null) {
log.warn("Directory '"+dirName+"' does not exist.");
return;
}
long latestMod = lastDate;
for(File updFile: updatedFiles) {
long lm = updFile.lastModified();
latestMod = (lm > latestMod) ? lm : latestMod;
}
if(updatedFiles.length > 0) {
// notify call back...
log.info("Directory '"+dirName+"' contents updated, notifying listener.");
listener.filesUpdatedOrAdded(updatedFiles);
} else if (log.isDebugEnabled()) {
log.debug("Directory '"+dirName+"' contents unchanged.");
}
// It is the JobDataMap on the JobDetail which is actually stateful
context.getJobDetail().getJobDataMap().put(LAST_MODIFIED_TIME, latestMod);
}
protected File[] getUpdatedOrNewFiles(String dirName, final long lastDate, final long maxAgeDate) {
File dir = new File(dirName);
if(!dir.exists() || !dir.isDirectory()) {
return null;
}
File[] files = dir.listFiles(new FileFilter() {
public boolean accept(File pathname) {
if(pathname.lastModified() > lastDate && pathname.lastModified() < maxAgeDate)
return true;
return false;
}});
if(files == null)
files = new File[0];
return files;
}
}