如何异步启动 Spring Batch 作业

Question

我遵循了spring 批处理文档，但无法异步运行我的工作。

所以我从 web 容器运行作业，作业将通过 REST 端点触发。

我想在完成整个工作之前获得 JobInstance ID以作为响应传递它。因此，他们可以稍后使用 JobInstance ID 检查作业的状态，而无需等待。但我无法让它工作。下面是我试过的示例代码。请让我知道我错过了什么或错了什么。

BatchConfig 使 Async JobLauncher

@Configuration
public class BatchConfig {

    @Autowired
    JobRepository jobRepository;


    @Bean
    public JobLauncher simpleJobLauncher() throws Exception {
        SimpleJobLauncher jobLauncher = new SimpleJobLauncher();
        jobLauncher.setJobRepository(jobRepository);
        jobLauncher.setTaskExecutor(new SimpleAsyncTaskExecutor());
        jobLauncher.afterPropertiesSet();
        return jobLauncher;
    }
}

控制器

@Autowired
JobLauncher jobLauncher;

@RequestMapping(value="/trigger-job", method = RequestMethod.GET)
public Long workHard() throws Exception {
    JobParameters jobParameters = new JobParametersBuilder().
            addLong("time", System.currentTimeMillis())
            .toJobParameters();
    JobExecution jobExecution = jobLauncher.run(batchComponent.customJob("paramhere"), jobParameters);
    System.out.println(jobExecution.getJobInstance().getInstanceId());
    System.out.println("OK RESPONSE");
    return jobExecution.getJobInstance().getInstanceId();
}

和 JobBuilder 作为组件

@Component
public class BatchComponent {

    @Autowired
    private JobBuilderFactory jobBuilderFactory;

    @Autowired
    private StepBuilderFactory stepBuilderFactory;

    public Job customJob(String someParam) throws Exception {
        return jobBuilderFactory.get("personProcessor")
                .incrementer(new RunIdIncrementer()).listener(listener())
                .flow(personPorcessStep(someParam)).end().build();
    }


    private Step personPorcessStep(String someParam) throws Exception {
        return stepBuilderFactory.get("personProcessStep").<PersonInput, PersonOutput>chunk(1)
                .reader(new PersonReader(someParam)).faultTolerant().
                        skipPolicy(new DataDuplicateSkipper()).processor(new PersonProcessor())
                .writer(new PersonWriter()).build();
    }


    private JobExecutionListener listener() {
        return new PersonJobCompletionListener();
    }

    private class PersonInput {
        String firstName;

        public PersonInput(String firstName) {
            this.firstName = firstName;
        }

        public String getFirstName() {
            return firstName;
        }

        public void setFirstName(String firstName) {
            this.firstName = firstName;
        }
    }

    private class PersonOutput {
        String firstName;

        public String getFirstName() {
            return firstName;
        }

        public void setFirstName(String firstName) {
            this.firstName = firstName;
        }
    }

    public class PersonReader implements ItemReader<PersonInput> {
        private List<PersonInput> items;
        private int count = 0;

        public PersonReader(String someParam) throws InterruptedException {
            Thread.sleep(10000L); //to simulate processing
            //manipulate and provide data in the read method
            //just for testing i have given some dummy example
            items = new ArrayList<PersonInput>();
            PersonInput pi = new PersonInput("john");
            items.add(pi);
        }

        @Override
        public PersonInput read() {
            if (count < items.size()) {
                return items.get(count++);
            }
            return null;
        }
    }


    public class DataDuplicateSkipper implements SkipPolicy {

        @Override
        public boolean shouldSkip(Throwable exception, int skipCount) throws SkipLimitExceededException {
            if (exception instanceof DataIntegrityViolationException) {
                return true;
            }
            return true;
        }
    }


    private class PersonProcessor implements ItemProcessor<PersonInput, PersonOutput> {

        @Override
        public PersonOutput process(PersonInput item) throws Exception {
            return null;
        }
    }

    private class PersonWriter implements org.springframework.batch.item.ItemWriter<PersonOutput> {
        @Override
        public void write(List<? extends PersonOutput> results) throws Exception {
            return;
        }
    }

    private class PersonJobCompletionListener implements JobExecutionListener {
        public PersonJobCompletionListener() {
        }

        @Override
        public void beforeJob(JobExecution jobExecution) {

        }

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

主功能

@SpringBootApplication
@EnableBatchProcessing
@EnableScheduling
@EnableAsync
public class SpringBatchTestApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringBatchTestApplication.class, args);
    }
}

我正在使用基于注释的配置，并将 gradle 与以下批处理包一起使用。

compile('org.springframework.boot:spring-boot-starter-batch')

如果需要更多信息，请告诉我。我找不到任何示例来运行这个常见用例。

谢谢你的时间。

Answer 1

试试这个，在您的配置中，您需要使用@Bean(name = "myJobLauncher")创建带有SimpleAsyncTaskExecutor的customJobLauncher，并且将在您的控制器中使用@Qualifier。

@Bean(name = "myJobLauncher")
public JobLauncher simpleJobLauncher() throws Exception {
    SimpleJobLauncher jobLauncher = new SimpleJobLauncher();
    jobLauncher.setJobRepository(jobRepository);
    jobLauncher.setTaskExecutor(new SimpleAsyncTaskExecutor());
    jobLauncher.afterPropertiesSet();
    return jobLauncher;
}

在您的控制器中

@Autowired
@Qualifier("myJobLauncher")
private JobLauncher jobLauncher;

Answer 2

如果我查看你的代码，我会发现一些错误。首先，您的自定义配置未加载，因为如果加载，则同一接口的重复 bean 实例的注入将会失败。

Spring Boot 有很多魔力，但是如果你不告诉他进行一些组件扫描，则不会按预期加载任何内容。

我看到的第二个问题是您的 BatchConfig 类：它不会扩展 DefaultBatchConfigure，也不会覆盖 getJobLauncher()，因此即使启动魔法会加载所有内容，您也会获得默认的。这是一个可以使用的配置，并且它符合文档@EnableBatchProcessing API

批量配置

@Configuration
@EnableBatchProcessing(modular = true)
@Slf4j
public class BatchConfig extends DefaultBatchConfigurer {

  @Override
  @Bean
  public JobLauncher getJobLauncher() {
    try {
      SimpleJobLauncher jobLauncher = new SimpleJobLauncher();
      jobLauncher.setJobRepository(getJobRepository());
      jobLauncher.setTaskExecutor(new SimpleAsyncTaskExecutor());
      jobLauncher.afterPropertiesSet();
      return jobLauncher;

    } catch (Exception e) {
      log.error("Can't load SimpleJobLauncher with SimpleAsyncTaskExecutor: {} fallback on default", e);
      return super.getJobLauncher();
    }
  }
}

主功能

@SpringBootApplication
@EnableScheduling
@EnableAsync
@ComponentScan(basePackageClasses = {BatchConfig.class})
public class SpringBatchTestApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringBatchTestApplication.class, args);
    }
}

Answer 3

JobExecution jobExecution = jobLauncher.run(batchComponent.customJob("paramhere"), jobParameters);。Joblauncher 将在作业完成后等待，然后再返回任何内容，这就是为什么您的服务可能需要很长时间才能响应（如果这是您的问题）。如果您想要异步功能，您可能需要看看 Spring 的@EnableAsync& @Async。

@EnableAsync