Introducing Spring Framework

Chapter 13 ■ Adding E-mail and Scheduling Tasks
Listing 13-10 shows the urlCheck method that will run every 10 seconds. This method will get all the documents
that are a web type; for every document found, it will use its location to send a request and get a response. If the
response is good, it will log “URL is still valid”; if not, it will log “URL INVALID”. It uses the java.net.URL class to send
the request to the URL (the document’s location).
For testing purposes, you are testing the web types; you can modify the code in order to verify that the location
of a note, PDF, or any other type of document is still valid. Also, there are very good resources on the cron-tab
expressions on the Web if you want to learn more.
You can use the same code in Listing 13-9 (MyDocumentTest.java) and run it with
gradle :ch13:test
and see results like the following:
2014-03-19 22:30:50,005 DEBUG [pool-1-thread-1] @@ Checking valid WEB type Document's URL...
2014-03-19 22:30:50,937 DEBUG [pool-1-thread-1] Name lookup: Pro Spring Security
2014-03-19 22:30:50,937 DEBUG [pool-1-thread-1] Code: 200
2014-03-19 22:30:50,937 INFO [pool-1-thread-1] URL is still valid!!
2014-03-19 22:30:51,717 DEBUG [pool-1-thread-1] Name lookup: Bad Book
2014-03-19 22:30:51,717 DEBUG [pool-1-thread-1] Code: 404
2014-03-19 22:30:51,717 ERROR [pool-1-thread-1] URL INVALID! Code: 404. Please let know the
AdministratorL
2014-03-19 22:30:51,935 DEBUG [pool-1-thread-1] Name lookup: Pro Spring 3
2014-03-19 22:30:51,935 DEBUG [pool-1-thread-1] Code: 200
2014-03-19 22:30:51,935 INFO [pool-1-thread-1] URL is still valid!!
Using the book’s companion source code, you can find the data.sql. There are some new records that contain
bad data. Those records are being checked by the document scheduler every 10 seconds.
Summary
In this chapter, you saw that sending e-mail is easy with the Spring Framework e-mail’s helper classes. Also, you saw
that the @Async annotation helps to call a method asynchronously.
You added a new feature to the Spring application that can validate the Location field and report back if it is still
valid or not. As you can see, the Spring Framework offers very cool features for every task.
In the next chapter, you’ll start using other languages besides Java, and you’ll see how they interact with the
Spring container.
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