CronResource

Often, applications need to run a task at specific times. The CronResource provides a standard way of doing that. Applications need only create a standard java.lang.Runnable task and configure the CronResource. Resin configure's the work task with bean-style configuration .

Task running every 15 minutes

<web-app xmlns="http://caucho.com/ns/resin"> <resource type="com.caucho.resources.CronResource"> <init> <cron>*/15</cron> <work resin:type="example.PeriodicWork"> <foo>Custom Config</foo> </work> </init> </resource> </web-app>

com.caucho.resources.CronResource

Parameter Meaning default

cron Specifies the times the task should be run required

work Specifies application's work bean required

The cron specification follows the Unix crontab format. The cron is composed of 5 fields: minutes, hours, day of month, month, and day of week.

Each field specifies a range of times to be executed. The patterns allowed are:

example ranges
range explanation (using minutes as example)

* run every minute

*/5 run every 5 minutes

0,5,50 run at :00, :05, :50 every hour

0-4 run at :00, :01, :02, :03, :04

0-30/2 run every 2 minutes for the first half hour

The minutes field is always required, and the hours, days, and months fields are optional.

example times
range explanation

0 */3 run every 3 hours

15 2 * run every day at 0215 local time

0 0 */3 run every third day at midnight

15 0 * * 6 run every Saturday at 0015

Hello, World example

WEB-INF/web.xml

<web-app xmlns="http://caucho.com/ns/resin"> <resource type="com.caucho.resources.CronResource"> <init>  <cron>*</cron> <work resin:type="example.PeriodicWork"/> </init> </resource> </web-app>

WEB-INF/classes/example/PeriodicWork.java

package example; import java.util.logging.Level; import java.util.logging.Logger; public class PeriodicWork implements Runnable { static protected final Logger log = Logger.getLogger(PeriodicWork.class.getName()); public PeriodicWork() { log.info("PeriodicWork: constructor"); } /** * Required implementation of java.lang.Runnable.run() */ public void run() { log.info("PeriodicWork: run() Hello, World"); } }

[13:04:27.429] PeriodicWork: constructor [13:05:00.095] PeriodicWork: run() Hello, World [13:06:00.182] PeriodicWork: run() Hello, World

bean-style configuration example

WEB-INF/classes/example/PeriodicWork.java

package example; import java.util.logging.Level; import java.util.logging.Logger; import javax.resource.spi.work.Work; public class PeriodicWork implements Work { static protected final Logger log = Logger.getLogger(PeriodicWork.class.getName()); String _message; public PeriodicWork() { log.info("PeriodicWork: constructor"); } /** * Optional, called in response to presence of <message> * configuration tag. */ public void setMessage(String message) { log.info("PeriodicWork: setMessage"); _message = message; } /** * Optional, called after bean is created and any setters * from configuration are called. */ public void init() throws Exception { log.info("PeriodicWork: init()"); if (_message == null) throw new Exception("`message' is required"); } /** * Required implementation of java.lang.Runnable.run() */ public void run() { log.info("PeriodicWork: run() " + _message); } /** * Implementation of javax.resource.spi.work.Work.release() */ public void release() { log.info("PeriodicWork: release()"); } }

[13:04:27.429] PeriodicWork: constructor [13:04:27.429] PeriodicWork: setMessage [13:04:27.429] PeriodicWork: init() [13:05:00.095] PeriodicWork: run() Goodbye, World [13:06:00.182] PeriodicWork: run() Goodbye, World (close Resin) [13:06:00.345] PeriodicWork: release()

Library

RMI