This version is still in development and is not considered stable yet. For the latest stable version, please use Spring Batch Documentation 5.1.2!spring-doc.cn

This version is still in development and is not considered stable yet. For the latest stable version, please use Spring Batch Documentation 5.1.2!spring-doc.cn

When you use @EnableBatchProcessing, a JobRegistry is provided for you. This section describes how to configure your own.spring-doc.cn

The most basic implementation of the JobLauncher interface is the TaskExecutorJobLauncher. Its only required dependency is a JobRepository (needed to obtain an execution).spring-doc.cn

The following example shows a TaskExecutorJobLauncher in Java:spring-doc.cn

Java Configuration
...
@Bean
public JobLauncher jobLauncher() throws Exception {
	TaskExecutorJobLauncher jobLauncher = new TaskExecutorJobLauncher();
	jobLauncher.setJobRepository(jobRepository);
	jobLauncher.afterPropertiesSet();
	return jobLauncher;
}
...

The following example shows a TaskExecutorJobLauncher in XML:spring-doc.cn

XML Configuration
<bean id="jobLauncher"
      class="org.springframework.batch.core.launch.support.TaskExecutorJobLauncher">
    <property name="jobRepository" ref="jobRepository" />
</bean>

Once a JobExecution is obtained, it is passed to the execute method of Job, ultimately returning the JobExecution to the caller, as the following image shows:spring-doc.cn

Job Launcher Sequence
Figure 1. Job Launcher Sequence

The sequence is straightforward and works well when launched from a scheduler. However, issues arise when trying to launch from an HTTP request. In this scenario, the launching needs to be done asynchronously so that the TaskExecutorJobLauncher returns immediately to its caller. This is because it is not good practice to keep an HTTP request open for the amount of time needed by long running processes (such as batch jobs). The following image shows an example sequence:spring-doc.cn

Async Job Launcher Sequence
Figure 2. Asynchronous Job Launcher Sequence

You can configure the TaskExecutorJobLauncher to allow for this scenario by configuring a TaskExecutor.spring-doc.cn

The following Java example configures a TaskExecutorJobLauncher to return immediately:spring-doc.cn

Java Configuration
@Bean
public JobLauncher jobLauncher() {
	TaskExecutorJobLauncher jobLauncher = new TaskExecutorJobLauncher();
	jobLauncher.setJobRepository(jobRepository());
	jobLauncher.setTaskExecutor(new SimpleAsyncTaskExecutor());
	jobLauncher.afterPropertiesSet();
	return jobLauncher;
}

The following XML example configures a TaskExecutorJobLauncher to return immediately:spring-doc.cn

XML Configuration
<bean id="jobLauncher"
      class="org.springframework.batch.core.launch.support.TaskExecutorJobLauncher">
    <property name="jobRepository" ref="jobRepository" />
    <property name="taskExecutor">
        <bean class="org.springframework.core.task.SimpleAsyncTaskExecutor" />
    </property>
</bean>

You can use any implementation of the spring TaskExecutor interface to control how jobs are asynchronously executed.spring-doc.cn