具有许多可选步骤的JEE批处理作业规范 [英] JEE Batch Job Specification with many optional Steps

问题描述

是否可以使用JSR 352 Batch API实现以下逻辑? 我有一系列步骤，每个步骤都需要根据开始工作时已知的不同条件执行. 条件实体是由外部系统提供的.

Is there a way to achieve the following logic with JSR 352 Batch API? I have a series of Steps that each need to be executed based on a different condition known when starting the job. ConditionsEntity is provided by an external system.

public List<Steps> createStepSequence(ConditionsEntity conditions) {
  if (conditions.isStep1Enabled()) {
    steps.add(step1)
  }
  if (conditions.isStep2Enabled()) {
    steps.add(step2)
  }
  if (conditions.isStep3Enabled()) {
    steps.add(step3)
  }
  //many more ifs

return steps;
}

我的第一次尝试失败，原因是:com.ibm.jbatch.container.exception.BatchContainerRuntimeException:一个决定不能在另一个决定之前.我在这里添加失败代码

My first attempt fails because of: com.ibm.jbatch.container.exception.BatchContainerRuntimeException: A decision cannot precede another decision. I'm adding the FAILING Code here

<?xml version="1.0" encoding="UTF-8"?>
<job id="myJob" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/jobXML_1_0.xsd" version="1.0">
    <properties>
        <property name="isExecuteStep2" value="false"/>
        <property name="isExecuteStep3" value="false"/>
    </properties>
    <step id="step1" next="decider1">
        <batchlet ref="myBatchlet1"/>
    </step>
    <decision id="decider1" ref="SkipNextStepDecider">
        <properties>
            <property name="isExecuteNextStep" value="#{jobProperties['isExecuteStep2']}"/>
        </properties>
        <next on="EXECUTE" to="step2"/>
        <next on="SKIP" to="decider2"/>
    </decision>
    <step id="step2">
        <batchlet ref="myBatchlet2"/>
    </step>
    <decision id="decider2" ref="SkipNextStepDecider">
        <properties>
            <property name="isExecuteNextStep" value="#{jobProperties['isExecuteStep3']}"/>
        </properties>
        <next on="EXECUTE" to="step3"/>
        <end on="SKIP"/>
    </decision>
    <step id="step3">
        <batchlet ref="myBatchlet3"/>
    </step>
</job>


@Named
public class SkipNextStepDecider implements Decider {

    @Inject
    @BatchProperty
    private String isExecuteNextStep;

    @Override
    public String decide(StepExecution[] ses) throws Exception {
        if (isExecuteNextStep.equalsIgnoreCase("true")) {
            return "EXECUTE";
        } else {
            return "SKIP";
        }
    }
}

更新 我已经通过passThroughStep实现了以下建议的解决方案.它可以正常工作，但是我仍然希望能够避免所有这些代码重复.

UPDATE I have implemented the following suggested solution with a passThroughStep. It's working correctly, but I would still love to be able to avoid all this code duplication.

<?xml version="1.0" encoding="UTF-8"?>
<job id="decisionpoc" xmlns="http://xmlns.jcp.org/xml/ns/javaee" version="1.0">
    <step id="dummy0" next="decider1">
        <batchlet ref="dummyBatchlet"/>
    </step>
    <decision id="decider1" ref="skipNextStepDecider">
        <properties>
            <property name="condition" value="isExecuteStep1"/>
        </properties>
        <next on="EXECUTE" to="step1"/>
        <next on="SKIP" to="dummy1"/>
    </decision>
    <step id="step1" next="decider2">
        <batchlet ref="myBatchlet1"/>
    </step>
    <step id="dummy1" next="decider2">
        <batchlet ref="dummyBatchlet"/>
    </step>
    <decision id="decider2" ref="skipNextStepDecider">
        <properties>
            <property name="condition" value="isExecuteStep2"/>
        </properties>
        <next on="EXECUTE" to="step2"/>
        <next on="SKIP" to="dummy2"/>
    </decision>
    <step id="step2">
        <batchlet ref="myBatchlet2"/>
    </step>
    <step id="dummy2" next="decider3">
        <batchlet ref="dummyBatchlet"/>
    </step>
    <decision id="decider3" ref="skipNextStepDecider">
        <properties>
            <property name="condition" value="isExecuteStep3"/>
        </properties>
        <next on="EXECUTE" to="step3"/>
        <end on="SKIP"/>
    </decision>
    <step id="step3">
        <batchlet ref="myBatchlet3"/>
    </step>
</job>

决定者

@Named
public class SkipNextStepDecider implements Decider {

    @Inject
    @BatchProperty
    private String condition;

    @Inject
    private JobContext jobContext;

    @Override
    public String decide(StepExecution[] ses) throws Exception {
        Properties parameters = getParameters();
        String isExecuteNextStep = parameters.getProperty(condition);
        if (isExecuteNextStep.equalsIgnoreCase("true")) {
            return "EXECUTE";
        } else {
            return "SKIP";
        }
    }

    private Properties getParameters() {
        JobOperator operator = getJobOperator();
        return operator.getParameters(jobContext.getExecutionId());

    }
}

我的测试

public class DecisionPOCTest extends AbstractBatchLOT {

    @Test
    public void testProcess() throws Exception {
        JobOperator jobOperator = getJobOperator();
        Properties properties = new Properties();
        properties.setProperty("isExecuteStep1", "true");
        properties.setProperty("isExecuteStep2", "false");
        properties.setProperty("isExecuteStep3", "true");
        Long executionId = jobOperator.start("poc/decisionPOC", properties);
        JobExecution jobExecution = jobOperator.getJobExecution(executionId);

        jobExecution = BatchTestHelper.keepTestAlive(jobExecution);


        List<StepExecution> stepExecutions = jobOperator.getStepExecutions(executionId);
        List<String> executedSteps = new ArrayList<>();
        for (StepExecution stepExecution : stepExecutions) {
            executedSteps.add(stepExecution.getStepName());
        }

        assertEquals(COMPLETED, jobExecution.getBatchStatus());
        assertEquals(4, stepExecutions.size());
        assertArrayEquals(new String[]{"dummy0", "step1", "dummy2", "step3"}, executedSteps.toArray());
        assertFalse(executedSteps.contains("step2"));
    }
}

推荐答案

该失败似乎是由于一个决定在运行时将另一个决定作为下一个执行点而导致的.根据JSR 352规范8.5节，它应该是受支持的用例:

It looks like the failure was caused by the fact that one decision had another decison as its next execution point at runtime. As per the JSR 352 spec Section 8.5, it should be a supported use case:

作业可以包含任意数量的决策元素.决策要素 是作业级步骤，流程中下一个"属性的目标， 分裂或其他决定.

A job may contain any number of decision elements. A decision element is the target of the "next" attribute from a job-level step, flow, split, or another decision.

作为一种解决方法，您可以尝试使用一个传递批处理步骤，该步骤包含相同的条件和逻辑.例如，

As a workaround, you can try having a pass-through batchlet-step that contains the same condition and logic. For example,

<step id="pass-through-step">
   <batchlet ref="PassThroughBatchlet"/>
   <next on="EXECUTE" to="step2"/>
   <next on="SKIP" to="decider2"/>
</step>

或者如果您的某些条件逻辑可以通过包含过渡元素的批处理步骤来实现，则可以取消这些决策.

Or if some of your conditional logic can be achived with a batchlet-step containing transition elements, you can do away with those decisions.

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