Introducing Spring Framework

Chapter 13 ■ Adding E-mail and Scheduling Tasks
public void testAsyncEmail() throws InterruptedException{
log.debug("Testing Async Email...");
assertNotNull(email);
long start = new Date().getTime();
email.sendAsync("user@gmail.com", "user@gmail.com", "New Document Add",
"A new document was added to the collection.");
}
long end = new Date().getTime();
long time = (end - start)/1000;
log.debug("Sending Async email done. Took: " + time + " seconds.");
}
Running the test with
gradle :ch13:test
you should have the following output:
2014-03-19 22:19:33,567 DEBUG [main] Testing Async Email...
2014-03-19 22:19:33,568 DEBUG [main] Sending Async email done. Took: 0 seconds.
It returns immediately! Now you can take care of more business logic, and let those heavy tasks run in the
background.
Let’s Schedule
Another feature you need to add to your Spring application is to periodically check out if any document’s location
(on the hard drive or on the Web) is still valid. Because you have some web document types, you need to check this
often for any broken resource links.
The Spring Framework provides Schedulers classes that can help you with these tasks. Let’s create a simple
example and see how easy it is to schedule a task every three seconds. Listing 13-8 shows the example.
Listing 13-8. DocumentScheduler.java
package com.apress.isf.spring.scheduler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
@Component
public class DocumentScheduler {
private static Logger log = LoggerFactory.getLogger(DocumentScheduler.class);
}
@Scheduled(fixedRate=3000)
public void sampleCronMethod(){
log.debug("Running every 3 seconds...");
}
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