将 Spring Batch Tasklet 失败消息传递给报告步骤。

Question

我正在使用带有 OpenCSV 的 Spring Batch Tasklet 来读取我的 CSV 文件。在问这个问题之前，我知道块，但是在后面的步骤中文件之间存在交叉验证，所以我必须继续使用Tasklet。

我要做的是向我的报告步骤报告丢失的文件或解析错误。我不确定向下一步报告失败的正确方法应该是什么。我有以下代码。

读取文件的初始步骤。

public class CsvBatchReader<T> implements Tasklet, StepExecutionListener {

    private final Logger logger = LoggerFactory.getLogger(CsvBatchReader.class);

    private List batch;

    private final Class<T> clazz;

    private Path path;

    public CsvBatchReader(Class<T> clazz, Path path) {

        this.clazz = clazz;

        this.path = path;

    }

    @Override

    public void beforeStep(StepExecution stepExecution) {

        logger.info("Reader initialized - " + clazz.getSimpleName());

        batch = new ArrayList();

    }

    @Override

    public ExitStatus afterStep(StepExecution stepExecution) {

        logger.info("Reader ended - " + clazz.getSimpleName());

        return ExitStatus.COMPLETED;

    }

    @Override

    public RepeatStatus execute(StepContribution contribution, ChunkContext chunkContext) throws UnexpectedJobExecutionException {

        logger.info("Reader execute - " + clazz.getSimpleName());

        ICsvToBean csvToBean = new CsvToBean(clazz, path);

        try {

            batch = csvToBean.readCsv();

        } catch(IOException ex) {

            // error message being caught from my csvToBean class. 

            throw new UnexpectedJobExecutionException("Invalid file " + ex.getMessage());

        }

        return RepeatStatus.FINISHED;

    }

}

报告步骤

我不确定如何传入异常消息，或者是否定义了在不使用 Step Execution Context 的情况下传入失败消息的方法。

public class CsvBatchReporting implements Tasklet, StepExecutionListener {

    private final Logger logger = LoggerFactory.getLogger(CsvBatchCrossValidation.class);

    private List errorMessages;

    private List skippedInserts;

Answer 1

我不确定如何传入异常消息，或者是否定义了在不使用 Step Execution Context 的情况下传入失败消息的方法。您可以从作业执行中访问上一步中抛出的异常。下面是一个例子：import java.util.List;import org.springframework.batch.core.Job;import org.springframework.batch.core.JobExecution;import org.springframework.batch.core.JobParameters;import org.springframework.batch.core.Step;import org.springframework.batch.core.StepExecution;import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing;import org.springframework.batch.core.configuration.annotation.JobBuilderFactory;import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;import org.springframework.batch.core.launch.JobLauncher;import org.springframework.batch.repeat.RepeatStatus;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.context.ApplicationContext;import org.springframework.context.annotation.AnnotationConfigApplicationContext;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;@Configuration@EnableBatchProcessingpublic class MyJob {&nbsp; &nbsp; @Autowired&nbsp; &nbsp; private JobBuilderFactory jobs;&nbsp; &nbsp; @Autowired&nbsp; &nbsp; private StepBuilderFactory steps;&nbsp; &nbsp; @Bean&nbsp; &nbsp; public Step step1() {&nbsp; &nbsp; &nbsp; &nbsp; return steps.get("step1")&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .tasklet((contribution, chunkContext) -> {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; System.out.println("hello");&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; throw new Exception("Boom!");&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; })&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .build();&nbsp; &nbsp; }&nbsp; &nbsp; @Bean&nbsp; &nbsp; public Step step2() {&nbsp; &nbsp; &nbsp; &nbsp; return steps.get("step2")&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .tasklet((contribution, chunkContext) -> {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; JobExecution jobExecution = chunkContext.getStepContext().getStepExecution().getJobExecution();&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; StepExecution stepExecution = jobExecution.getStepExecutions().iterator().next(); // TODO properly get the stepExecution of the previous step&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; List<Throwable> failureExceptions = stepExecution.getFailureExceptions();&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if (!failureExceptions.isEmpty()) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Throwable throwable = failureExceptions.get(0);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; System.out.println("Looks like step1 has thrown an exception: " + throwable.getMessage());&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; System.out.println("world");&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return RepeatStatus.FINISHED;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; })&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .build();&nbsp; &nbsp; }&nbsp; &nbsp; @Bean&nbsp; &nbsp; public Job job() {&nbsp; &nbsp; &nbsp; &nbsp; return jobs.get("job")&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .flow(step1())&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .on("*").to(step2())&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .build()&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .build();&nbsp; &nbsp; }&nbsp; &nbsp; public static void main(String[] args) throws Exception {&nbsp; &nbsp; &nbsp; &nbsp; ApplicationContext context = new AnnotationConfigApplicationContext(MyJob.class);&nbsp; &nbsp; &nbsp; &nbsp; JobLauncher jobLauncher = context.getBean(JobLauncher.class);&nbsp; &nbsp; &nbsp; &nbsp; Job job = context.getBean(Job.class);&nbsp; &nbsp; &nbsp; &nbsp; jobLauncher.run(job, new JobParameters());&nbsp; &nbsp; }}此示例打印：helloLooks like step1 has thrown an exception: Boom!world显然，您需要确保在所有情况下 step1 都流向 step2（因此是流定义）。希望这可以帮助。