Best practice to solve this problem

[Demo]

Hi,

I have different loaders which share a common functionality, implemented in the ExchangerLoader:

public abstract class ExchangerLoader {
    // Declarations
    protected IMapper mapper;
    protected IDocumentHandler docHandler;
    protected String initialProcess = "AKT";

    /*
     * DEPENDENCY INJECTIONS
     */
    public void setDocumentHandler(IDocumentHandler docHandler) {
        this.docHandler = docHandler;
    }

    public void setInitialProcess(String process) {
        this.initialProcess = process;
    }

    public void setDataMapper(IMapper mapper) {
        this.mapper = mapper;
    }

    //Some shared methods, which are used by all loaders

   //This class must be implement by all derived classes
    public abstract String loadData(String docId, String folder, String type, String viewField);

Now I've specific loaders:
- ViewLoader
- ObjectLoader
- TreeLoader

These loaders extend the ExchangeLoader and implements the loadData-Method. The specific loaders also access methods from the ExchangerLoader.

    <!-- LOADERS -->
    <bean id="viewLoader" class="com.mycomp.exchanger.loader.ViewLoader">
        <property name="documentHandler">
            <ref bean="documentHandler"/>
        </property>
        <property name="dataMapper">
            <ref bean="mapperService"/>
        </property>
    </bean>
    <bean id="objectLoader" class="com.mycomp.exchanger.loader.ObjectLoader">
        <property name="documentHandler">
            <ref bean="documentHandler"/>
        </property>
        <property name="dataMapper">
            <ref bean="mapperService"/>
        </property>
    </bean>
    <bean id="treeLoader" class="com.mycomp.exchanger.loader.TreeLoader">
        <property name="documentHandler">
            <ref bean="documentHandler"/>
        </property>
        <property name="dataMapper">
            <ref bean="mapperService"/>
        </property>
    </bean>

The configured loaders are now injected to a service which decides what loader should be used. I think this is an implementation of the Strategy Design pattern. Now my question, as you can see on the declaration above all my loaders need the documentHandler and mapperService. Is there a better way to configure these loaders?

thank you for your advices

markus

[gmazza]

Now my question, as you can see on the declaration above all my loaders need the documentHandler and mapperService. Is there a better way to configure these loaders?

I think you are looking for bean inheritance[1]. Try it and let us know if it works.

Glen

[1] http://yan.codehaus.org/Bean+Reusability+Compared

[Colin Yates]

Is there a better way to configure these loaders?

You can specify parent="" for a bean to inherit the definition of the specified bean.

[Demo]

I use the configuration posted on the mentioned site http://yan.codehaus.org/Bean+Reusability+Compared

wow! In the manner of maintaining this is beautiful.

thanks again, markus

[Injecteer]

hmm, just took a look at
http://yan.codehaus.org/Spring,+Pico+and+Nuts+Compared

the comparison table there is quite funny for example:
Life cycle:
Spring: Singleton only,
Pico: Singleton only,
Yan: Both singleton and prototype

nice isnt'it? so, enough of Spring, I'll switch to Yan/Nuts !

[Colin Yates]

http://yan.codehaus.org/Spring,+Pico+and+Nuts+Compared

There are a number of errors in that comparison table

I couldn't find a way to inform the author though....

[Injecteer]

I'm just wondering, who would use something like Yan?
it looks more like a graduating project

[wpoitras]

hmm, just took a look at
http://yan.codehaus.org/Spring,+Pico+and+Nuts+Compared

the comparison table there is quite funny for example:
Life cycle:
Spring: Singleton only,
Pico: Singleton only,
Yan: Both singleton and prototype

nice isnt'it? so, enough of Spring, I'll switch to Yan/Nuts !

I believe what he's referring to is that prototypes don't participate in the complete Spring lifecycle (no destroy-method). That of course is misleading since prototypes do invoke their init-method.

As for a contact, its on the Yan home page: Ben Yu