Is it possible to create a collections with Spring configuration?

问题

Suppose I have a class MyClass which can be instantiated either with String or it have predefined static instances inside a class.

Something like this:

public class MyClass {

   public final static MyClass A = new MyClass("A");
   public final static MyClass B = new MyClass("B");
   public final static MyClass C = new MyClass("C");
   ...

   public MyClass(String name) {
      ...
   }
}

Is it possible to create an ArrayList<MyClass> bean in Spring config somehow? Something like

<bean id="sequence" class="...ArrayList"> 
    <member class="...MyClass" value="A"/>
    <member ... />
    ....
</bean>

UPDATE 1

Is it possible to write following way:

<bean id="sequence" class="...ArrayList"> 
  <constructor-arg>
     <list>
         <bean class="...MyClass" constructor-arg="A"/>
         <bean class="...MyClass" constructor-arg="B"/>
         <bean class="...MyClass" constructor-arg="C"/>
     </list>
  </constructor-arg>
</bean>

回答1:

You could do:

<bean id="myClassA" class="org.foo.MyClass"> 
   <constructor-arg>
     <bean class="java.lang.String">
       <constructor-arg value="A"/>
     </bean>   
   <constructor-arg>
</bean>

<bean id="sequence" class="java.util.ArrayList">
    <constructor-arg>
        <list>
            <ref bean="myClassA" />
            ...
        </list>
    </constructor-arg>
</bean>

Note, however, that the most common approach is to inject a list directly into a bean rather than wrapping a list within a list first.

回答2:

You should have a look at the Collections section in the spring IOC documentation.

<bean id="moreComplexObject" class="example.ComplexObject">
  <property name="someList">
    <list>
      <value>a list element followed by a reference</value>
      <ref bean="myDataSource" />
    </list>
  </property>    
</bean>

回答3:

Yes. You can even create it as a standalone bean. See this thread for two examples.

来源：https://stackoverflow.com/questions/14012524/is-it-possible-to-create-a-collections-with-spring-configuration

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java

Spring

collections

inversion-of-control