Dependency tree from spring batch configuration

Having a spring job definition:

<job id="footballJob"开发者_如何转开发>
    <!-- Step bean details ommitted for clarity -->
    <step id="playerload" next="gameLoad"/>
    <step id="gameLoad" next="playerSummarization"/>
    <step id="playerSummarization"/>
</job>

Can I progmatically figure out the order of steps to execute?

Can I progmatically figure out the order of steps to execute?

by taking your question literally there are some options:

• use Spring Tool Suite afaik it can display job flows
• parse job.xml by yourself, you could even use a spring batch job which would be quite funny
• try to grok the complete batch setup process, start with spring.handlers and CoreNamespaceHandler.java, you can overwrite it by your needs
  • SimpleFlow.java should be sufficient

i would go with a simple xml parser

Steps will execute in order that you listed in your example.

In case you'd like to specify the order you can do:

<job id="job">
    <step id="stepA" parent="s1" next="stepB" />
    <step id="stepB" parent="s2" next="stepC"/>
    <step id="stepC" parent="s3" />
</job>

In case you'd like a non sequential step execution / conditional flow, you can do:

<job id="job">
    <step id="stepA" parent="s1">
        <next on="*" to="stepB" />
        <next on="FAILED" to="stepC" />
    </step>
    <step id="stepB" parent="s2" next="stepC" />
    <step id="stepC" parent="s3" />
</job>

In order to control the flow programmatically, depending on ExitStatus, you can inject your own decider:

public class MyDecider implements JobExecutionDecider {
    public FlowExecutionStatus decide(JobExecution jobExecution, StepExecution stepExecution) {
        if (someCondition) {
            return "FAILED";
        }
        else {
            return "COMPLETED";
        }
    }
}

In the job configuration, a "decision" tag will specify the decider to use as well as all of the transitions:

<job id="job">
    <step id="step1" parent="s1" next="decision" />

    <decision id="decision" decider="decider">
        <next on="FAILED" to="step2" />
        <next on="COMPLETED" to="step3" />
    </decision>

    <step id="step2" parent="s2" next="step3"/>
    <step id="step3" parent="s3" />
</job>

<beans:bean id="decider" class="com.MyDecider"/>

EDIT:

If you are looking to get a dependency graph, you can just use Spring Tool Suite to visualize the flow, here is a simple example.