如何在 Spring Batch 中创建动态步骤

Question

我需要创建“N”个步骤，具体取决于从数据库接收到的“maxHierLevel”值并按顺序执行它们 -

int maxHierLevel = testService.getHighestLevel(); 

Step masterCalculationStep = stepBuilderFactory.get("CALCUL_STEP_1")
        .<Map<Long, List<CostCalculation>>, List<TempCostCalc>>chunk(1)
        .reader(reader)
        .processor(processor)
        .writer(writer)
        .build();

final Step[] stepsArray = new Step[maxHierLevel];

for (int i = 0; i < stepsArray.length; i++) {
    stepsArray [i] = stepBuilderFactory.get("processingRecordsInLevel_"+i)
            .partitioner("partitionningSlavStep_"+i , calculationPartioner(i))
            .step(masterCalculationStep)
            .listener(new StepResultListener())
            .taskExecutor(taskExecutor)
            .build();
}

return jobBuilderFactory.get("mainCalculationJob")
                .incrementer(new RunIdIncrementer())
                .flow(truncTableTaskletStep())
                .next(loadPlantList)
                .next(stepsArray[0]) 
                .next(stepsArray[1])
                .next(stepsArray[2])
                .end()
                .listener(listener)
                .build();

我们可以动态添加像 next(stepsArray[0]) 这样的步骤并返回作业 ref 吗？

Answer 1

是的，您可以动态创建步骤并返回作业参考。下面是一个示例，说明如何在您的情况下做到这一点：

@Bean
public Job job() {
    Step[] stepsArray = // create your steps array or pass it as a parameter
    SimpleJobBuilder jobBuilder = jobBuilderFactory.get("mainCalculationJob")
            .incrementer(new RunIdIncrementer())
            .start(truncTableTaskletStep());
    for (Step step : stepsArray) {
        jobBuilder.next(step);
    }
    return jobBuilder.build();
}

希望这会有所帮助。