Introducing Spring Framework

Chapter 4 ■ Using Beans Scopes
documentDAO(DocumentRepository){ bean ->
bean.scope = "prototype"
doc1 = ref("doc1")
doc2 = ref("doc2")
doc3 = ref("doc3")
doc4 = ref("doc4")
}
}
//More bean definitions omitted.
Listing 4-6 shows your Groovy script: mydocuments.groovy. Now you are using a variable to define the scope.
You don’t need to worry too much about the correct syntax for this Groovy configuration; you are going to see it in
detail in Chapter 18.
Running the test, you should get the same results: two different instances of the SearchEngine class
implementation (SearchEngineService) and two different instances of the DocumentDAO class implementation
(DocumentRepository). But what happens if you combine bean scopes between dependencies? Well, this is an
exercise that you can do as homework. You need to put in more logs in order to find out what is happening.
■ ■Note In the book’s source code, you will find all the tests and classes that have been modified for this chapter.
You can use this source code to do your homework, right?
Summary
In this chapter, you added logs to some constructors and methods to discover how the Spring container works.
You saw that by default the Spring container will create a single instance because the scope is a singleton, and every
time you get that bean you are going to have the same instance. If you change the scope of your beans to prototype,
every time you get your bean, the Spring container will create a new fresh instance of your class. In the book’s
companion source code, you can find the complete examples using the Java bean configuration, XML, annotations,
and the GroovyBeanDefinitionReader.
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