'How to write a spring bean with a constructor that contains a list?

I have a list as follows:

ArrayList<DiameterMessageHandler> handlers = new ArrayList<>();
handlers.add(new AARHandler());
handlers.add(new CERHandler());
handlers.add(new PPAHandler());
handlers.add(new STRHandler());
handlers.add(new DWRHandler());

I am wondering how to create a spring bean that takes handlers as one of its arguments, i.e. is it possible to do this in the applicationContext.xml - Do I have to create separate beans for the list and each of the handlers(AARHandler etc) first? Here is my applicationContext.xml

<bean id="DiameterClient" class="com.rory.ptspsim.diameterclient.DiameterClient" scope="singleton" init-method="start">
        <constructor-arg type="java.lang.String" index="0"><value>${pcca.host}</value></constructor-arg>      
        <constructor-arg index="1">WHAT GOES HERE?</constructor-arg>        
    </bean>
javaspringspring-mvcweb.xml


Solution 1:[1]

I think the most appropriate way to do that is:

<bean id="DiameterClient" class="com.rory.ptspsim.diameterclient.DiameterClient"       scope="singleton" init-method="start">
    <constructor-arg type="java.lang.String" index="0"><value>${pcca.host}</value></constructor-arg>
    <constructor-arg index="1">
       <list>
           <ref bean="aarHandler" />
           <ref bean="cerHandler" />     
           <ref bean="ppaHandler" />
           <ref bean="strHandler" />
           <ref bean="dwrHandler" />
       </list>       
    </constructor>
</bean>

Solution 2:[2]

If you want all available Handlers, Spring will also collect them for you via Autowiring:

public DiameterClient(@Autowired List<DiameterMessageHandler> handlers){
    this.handlers = handlers;
}

Now Spring will inject a List of all available Handlers.

See Spring Reference 4.9.2: @Autowired

Solution 3:[3]

<bean id="DiameterClient" class="com.rory.ptspsim.diameterclient.DiameterClient" scope="singleton" init-method="start">
    <constructor-arg type="java.lang.String" index="0"><value>${pcca.host}</value></constructor-arg>      
    <constructor-arg index="1">
      <list>
       <bean class="AARHandler"/>
       <bean class="CERHandler"/>
      </list>
    </constructor-arg>        
</bean>

Solution 4:[4]

    <list>
        <ref bean="handler1" />
        <ref bean="handler2" />
        <ref bean="handler3" />
        <ref bean="handler4" />
        <ref bean="handler5" />
    </list>


    <bean id="handler1" class="AARHandler"/>
    <bean id="handler2" class="CERHandler"/>
    <bean id="handler3" class="PPAHandler"/>
    <bean id="handler4" class="STRHandler"/>
    <bean id="handler5" class="DWRHandler"/>

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1
Solution 2 Sean Patrick Floyd
Solution 3 Adisesha
Solution 4 Paul Whelan

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