java - 每次我请求作业启动器创建新作业时如何重新启动批处理作业

Question

我已将 Spring Batch 配置为每当通过 API 调用从 UI 发出请求时就会触发作业。我面临的问题是，该工作仅在第一次时工作正常，而对于其他尝试，每当调用电话时，工作都不会按预期方式响应。似乎他们正在尝试恢复，但我想再次重新启动整个执行过程。感谢您提前提供的任何帮助。

主类

@SpringBootApplication
@EnableBatchProcessing
public class HelloWorldApplication 
{
    public static void main(String[] args) 
    {
        SpringApplication.run(HelloWorldApplication.class, args);
    }
}

配置.类

@Configuration
public class ListenerJobConfiguration 
{
    @Autowired
    private JobBuilderFactory jobBuilderFactory;

    @Autowired
    private StepBuilderFactory stepBuilderFactory;

    @Bean
    public ItemReader<String> reader()
    {
        return new ListItemReader<>
        (Arrays.asList("one","two","three"));
    }

    @Bean
    public ItemWriter<String> writer()
    {
        return new ItemWriter<String>() 
        {
            @Override
            public void write(List<? extends String> items) throws Exception 
            {
                for(String item:items)
                {
                    System.out.println("writing items "+item);
                }               
            }
        };
    }   

    @Bean
    public Step step1()
    {
        return stepBuilderFactory.get("step1")
                .<String,String>chunk(2)
                .faultTolerant()
                .listener(new ChunkListener())
                .reader(reader())
                .writer(writer())
                .build();       
    }

    @Bean
    public Job listenerJob()
    {
        return jobBuilderFactory.get("listenerJob"+new Date())
                .start(step1())
                .listener(new JobListener())
                .build();
    }

}

JobListener.class

public class JobListener implements JobExecutionListener 
{

    @Override
    public void beforeJob(JobExecution jobExecution) 
    {
        System.out.println("Before job");
    }

    @Override
    public void afterJob(JobExecution jobExecution) 
    {
        System.out.println("After job");    
    }

}

ChunkListener.class

public class ChunkListener 
{
    @BeforeChunk
    public void  beforeChunk(ChunkContext context)
    {
        System.out.println(">>  Before the chunk");
    }

    @AfterChunk
    public void afterChunk(ChunkContext context)
    {
        System.out.println("<<  After the chunk");
    }

}

Controller 类

@RestController
public class BatchController 
{

    @Autowired
    JobLauncher jobLauncher;

    @Autowired
    Job job;

    @RequestMapping("/jobLauncher")
    public void handle() throws Exception 
    {
        JobParametersBuilder builder = new JobParametersBuilder();
        builder.addDate("date", new Date());
        jobLauncher.run(job, builder.toJobParameters());
    }

    @GetMapping(value = "/test")
    public String test() 
    {
        return "test success";
    }

}

应用程序属性

spring.batch.job.enabled=false

第一次发出API请求时的响应

2019-05-24 01:03:53.578  INFO 5264 --- [nio-9999-exec-1] o.s.b.c.l.support.SimpleJobLauncher      : Job: [SimpleJob: [name=listenerJobFri May 24 01:03:42 IST 2019]] launched with the following parameters: [{date=1558640033401}]
Before job
2019-05-24 01:03:53.640  INFO 5264 --- [nio-9999-exec-1] o.s.batch.core.job.SimpleStepHandler     : Executing step: [step1]
>>  Before the chunk
writing items one
writing items two
<<  After the chunk
>>  Before the chunk
writing items three
<<  After the chunk
After job
2019-05-24 01:03:53.722  INFO 5264 --- [nio-9999-exec-1] o.s.b.c.l.support.SimpleJobLauncher      : Job: [SimpleJob: [name=listenerJobFri May 24 01:03:42 IST 2019]] completed with the following parameters: [{date=1558640033401}] and the following status: [COMPLETED]

其他时间回复

2019-05-24 01:05:02.072  INFO 5264 --- [nio-9999-exec-4] o.s.b.c.l.support.SimpleJobLauncher      : Job: [SimpleJob: [name=listenerJobFri May 24 01:03:42 IST 2019]] launched with the following parameters: [{date=1558640102047}]
Before job
2019-05-24 01:05:02.107  INFO 5264 --- [nio-9999-exec-4] o.s.batch.core.job.SimpleStepHandler     : Executing step: [step1]
>>  Before the chunk
<<  After the chunk
After job
2019-05-24 01:05:02.150  INFO 5264 --- [nio-9999-exec-4] o.s.b.c.l.support.SimpleJobLauncher      : Job: [SimpleJob: [name=listenerJobFri May 24 01:03:42 IST 2019]] completed with the following parameters: [{date=1558640102047}] and the following status: [COMPLETED]

每当发出请求时，我希望输出每次都相同(例如第一次，即正确执行)。

Answer 1

主要原因应该是Reader Bean。然而，当您在那里提供数据时，它是一个单例。因此，一旦您消耗了数据，它就不会提供任何服务。

至于解决方案，您可以使用@Scope("prototype")

或使用StepScope因为它也不是单例。