org.quartz.jobs

Class FileScanJob

java.lang.Object

org.quartz.jobs.FileScanJob

All Implemented Interfaces:

Job

@DisallowConcurrentExecution
@PersistJobDataAfterExecution
public class FileScanJob
extends Object
implements Job

Inspects a file and compares whether it's "last modified date" has changed since the last time it was inspected. If the file has been updated, the job invokes a "call-back" method on an identified FileScanListener that can be found in the SchedulerContext.

Author:

jhouse, pl47ypus

See Also:

FileScanListener

Field Summary

Fields

Modifier and Type	Field and Description
static String	FILE_NAME JobDataMap key with which to specify the name of the file to monitor.
static String	FILE_SCAN_LISTENER_NAME JobDataMap key with which to specify the FileScanListener to be notified when the file contents change.
static String	MINIMUM_UPDATE_AGE 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.

Constructor Summary

Constructors

Constructor and Description
FileScanJob()

Method Summary

Methods

Modifier and Type	Method and Description
void	execute(JobExecutionContext context) Called by the Scheduler when a Trigger fires that is associated with the Job.
protected long	getLastModifiedDate(String fileName)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

FILE_NAME

public static final String FILE_NAME

JobDataMap key with which to specify the name of the file to monitor.

See Also:

Constant Field Values

FILE_SCAN_LISTENER_NAME

public static final String FILE_SCAN_LISTENER_NAME

JobDataMap key with which to specify the FileScanListener to be notified when the file contents change.

See Also:

Constant Field Values

MINIMUM_UPDATE_AGE

public static final String MINIMUM_UPDATE_AGE

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.

See Also:

Constant Field Values

Constructor Detail

FileScanJob

public FileScanJob()

Method Detail

execute

public void execute(JobExecutionContext context)
             throws JobExecutionException

Description copied from interface: Job

Called by the Scheduler when a Trigger fires that is associated with the Job.

The implementation may wish to set a result object on the JobExecutionContext before this method exits. The result itself is meaningless to Quartz, but may be informative to JobListeners or TriggerListeners that are watching the job's execution.

Specified by:

execute in interface Job

Throws:

JobExecutionException - if there is an exception while executing the job.

See Also:

Job.execute(org.quartz.JobExecutionContext)

getLastModifiedDate

protected long getLastModifiedDate(String fileName)