CODEWITHSUNDEEP
javaspringconfig
Rollerball
Rollerball

Reputation: 13118

Spring injecting implementation bean

I have the following snippet from a conf spring file:

<bean id="taskletStep" abstract="true" class="org.springframework.batch.core.step.tasklet.TaskletStep">
        <property name="jobRepository" ref="jobRepository"/>
        <property name="transactionManager" ref="transactionManager"/>
    </bean>

    <bean id="hello" class="com.techavalanche.batch.PrintTasklet">
        <property name="message" value="Hello"/>
    </bean>

    <bean id="world" class="com.techavalanche.batch.PrintTasklet">
        <property name="message" value=" World!"/>
    </bean>

    <bean id="mySimpleJob" class="org.springframework.batch.core.job.SimpleJob">
        <property name="name" value="mySimpleJob" />
        <property name="steps">
            <list>
                <bean parent="taskletStep">
                    <property name="tasklet" ref="hello"/>
                </bean>

                <bean parent="taskletStep">
                    <property name="tasklet" ref="world"/>
                </bean>
            </list>
        </property>

To me it is not very clear the following bit:

<bean parent="taskletStep">
                    <property name="tasklet" ref="hello"/>
                </bean>

taskletStep it is an interface and does not have any property. However the code works fine, it seems that the bean with ID "hello" gets injected. Therefore I am asking, is this the standard way from the config file to inject a bean implementation (id: hello) to an interface bean (id: taskletStep)?

Upvotes: 0

Views: 235

Answers (1)

ninja.coder
ninja.coder

Reputation: 9658

It's a tasklet step in Spring Batch Job. What you are doing is perfectly fine. Alternatively, you can also do something like this:

<job id="mySimpleJob">
    <step id="step1">
        <tasklet ref="hello"/>
    </step>

    <step id="step2">
        <tasklet ref="world"/>
    </step>
</job>

Here is a complete reference: http://docs.spring.io/spring-batch/reference/htmlsingle/

Upvotes: 1

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