How can I pass Batch Job parameters to my batch job without using CommandLineRuner?

I have a spring batch job which should run at the start up of spring boot app and spring boot app must shut down as soon as the batch job finishes.

I have covered the above scenario by using spring.batch.job.enabled = true property in application.yml file.

It ran fine in the starting but since few last runs I am getting below error:

>org.springframework.batch.core.repository.JobInstanceAlreadyCompleteException: A job instance already exists and is complete for parameters={}. If you want to run this job again, change the parameters.

Now, I don't want to use CommandLineRunner which would have let me pass the JobParameters while running the job using JobLauncher. This batch job will run with in a container and should get triggered as soon as the container runs.

My batch job should run as soon as the spring boot apps runs and the app must shut down once the batch job finishes.

I am not sure if I can pass the Job parameters without using CommandLineRunner or not. If I can, can someone point me to the right direction?

My BatchConfiguration looks like this:

@Configuration
@EnableBatchProcessing
@Component
public class BatchConfiguration{

	@Autowired
	public JobBuilderFactory jobBuilderFactory;

	@Autowired
	public StepBuilderFactory stepBuilderFactory;

	@Autowired
	JobRepository jobRepository;


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


	@Bean
	public Job loadDataFromIodsIcOutbound(DataListener listener, Step inboundStep) {
		return jobBuilderFactory.get("jobName")
				.incrementer(new RunIdIncrementer())
				.listener(listener)
				.flow(inboundStep)
				.end()
				.build();
	}

</details>


# 答案1
**得分**: 1

这则消息说：

&gt; 作业实例已经存在并且已经完成

这不是错误。这意味着您的作业已经执行并且成功完成。这是Spring Batch作业的默认行为，应该防止在不更改任何参数的情况下多次运行作业。

如果您的用例不同，您想要能够再次启动相同的作业，那么您可以通过在步骤构建器中添加以下行来更改此默认设置：

.allowStartIfComplete(true)

要以编程方式使用特定参数启动Spring Batch作业，可以按照以下步骤操作：

1. 禁用自动启动

spring.batch.job.enabled=false

2. 实现ApplicationRunner并添加作业参数

@SpringBootApplication
public class BatchApplication implements ApplicationRunner {
@Autowired
JobLauncher jobLauncher;
@Autowired
Job job;

@Override
public void run(ApplicationArguments args) throws Exception {
    log.info("Spring Batch starting.");
    JobParameters params = new JobParametersBuilder()
            .addString("jobName", "MyJobName")
            .addLocalDateTime("currentTime", LocalDateTime.now())
            .toJobParameters();
    jobLauncher.run(job, params);
    log.info("Spring Batch done.");
}

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

}

这样，您的Spring应用程序将使用指定的参数运行批处理，然后退出。（假设它没有依赖于Spring Web、MVC或计划作业，否则它将继续运行）。

<details>
<summary>英文:</summary>

The messages says:

&gt; A job instance already exists and is complete

It is not an error. It means only that your job has been already executed and was successful. This is the default behavior of a Spring Batch job and should prevent running jobs more then once without changing any parameters.

If your use case is different and you want be able to start the same job again then you can change this default setting by adding this line to your step builder:

.allowStartIfComplete(true)

To start the Spring Batch job programmatically with specific parameters you can follow this steps:

1. disable automatic start

spring.batch.job.enabled=false

2. implement ApplicationRunner and add your job parameters

@SpringBootApplication
public class BatchApplication implements ApplicationRunner {
@Autowired
JobLauncher jobLauncher;
@Autowired
Job job;

@Override
public void run(ApplicationArguments args) throws Exception {
    log.info("Spring Batch starting.");
    JobParameters params = new JobParametersBuilder()
            .addString("jobName", "MyJobName")
            .addLocalDateTime("currentTime", LocalDateTime.now())
            .toJobParameters();
    jobLauncher.run(job, params);
    log.info("Spring Batch done.");
}

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

}

This way you Spring Application will run the batch with specified parameters and exit. (Assuming it has no dependencies to Spring Web or MVC or scheduled jobs in which cases it will continue running).

</details>



# 答案2
**得分**: 1

你可以将作业参数作为键值对传递到你的Spring Boot应用程序的命令行上：

```java -jar myjob.jar name=foo```

<details>
<summary>英文:</summary>

&gt; I am not sure if I can pass the Job parameters without using CommandLineRunner or not. If I can, can someone point me to the right direction?

You can pass job parameters to your spring boot app on the command line as key/value pairs:

java -jar- myjob.jar name=foo

</details>