12.4. Spring Framework Comprehension Check

1. Fill (1)-(4) such that the Bean dependency relation is as follows. Skip import statement.

   

   @Controller
   public class XxxController {
     (1)
     protected (2) yyyService;
   
     // omitted
   }
   

   @Service
   @Transactional
   public class YyyServiceImpl implements YyyService {
     (1)
     protected (4) zzzRepository;
   
     // omitted
   }
   

   Note

   @Service , @Controller are org.springframework.stereotype package annotations and @Transactional is the annotation of org.springframework.transaction.annotation.

2. Explain when to use @Controller, @Service, and @Repository respectively.

   Note

   Each of them is org.springframework.stereotype package annotation.

3. Explain the difference between @Resource and @Inject.

   Note

   @Resource is javax.annotation package annotation, and @Inject is javax.inject package annotation.

4. Explain the difference between singleton scope and prototype scope.

5. Fill (1)-(3) in the following Scope related description. However, either of “singleton” or “prototype” can be entered in (1) and (2), but same value cannot be entered for both. Skip the import statement.

   @Component
   (3)
   public class XxxComponent {
     // omitted
   }
   

   Note

   @Component is org.springframework.stereotype.Component.

   Scope of bean with @Component is (1) by default. When changing scope to (2), it is better to add (3) (refer to above source code).

6. In case of following Bean definition, what type of Bean is registered in DI container?

   <bean id="foo" class="xxx.yyy.zzz.Foo" factory-method="create">
       <constructor-arg index="0" value="aaa" />
       <constructor-arg index="1" value="bbb" />
   </bean>
   

7. Fill (1)-(3) of the following Bean definition such that contents in com.example.domain package becomes target of component scan.

   <context:(1) (2)="(3)" />
   

   Note

   Bean definition file should include the definition of

   xmlns:context=”http://www.springframework.org/schema/context”

8. Fill (1)-(2) in the following Properties file related description. Skip import statement.

   It is possible to read the Bean definition file in ${key} format by removing the settings in properties file, if properties file path is set in the locations attribute of <context:property-placeholder> element. Specify as shown in (1) to read any properties file under META-INF/spring directory under the class path. Moreover, @(2) annotation should be added as shown in the following codes where the read properties value can also be injected in Bean.

   <context:property-placeholder locations="(1)" />
   

   emails.min.count=1
   emails.max.count=4
   

   @Service
   @Transactional
   public class XxxServiceImpl implements XxxService {
     @xxx("${emails.min.count}") // (2)
     protected int emailsMinCount;
     @xxx("${emails.max.count}") // (2)
     protected int emailsMaxCount;
     // omitted
   }
   

   Note

   Bean definition file should include the definitions of

   xmlns:context=”http://www.springframework.org/schema/context”

9. Fill (1)-(5) in the following description for AOP Advice of Spring. The contents of (1)-(5) are all different.

   Note

   Advice (1) should be used when interrupting a process before calling a specific method, Advice (2) should be used when interrupting a process after calling a specific method. Advice (3) should be used when interrupting a process before and after calling a specific method. Advice (4) should be used only when the process is ended normally and Advice (5) should be used when there is an exception.

10. Insert (*) of following Bean definition for performing transaction management using @Transactional annotation.

    <tx:(*) />
    

    Note

    Bean definition file should include the definitions of

    xmlns:tx=”http://www.springframework.org/schema/tx”