Spring Batch - 基本应用

本章介绍基本的Spring Batch应用程序。它将简单地执行一个 tasklet 来显示一条消息。

我们的Spring Batch应用程序包含以下文件 -

配置文件 - 这是一个XML文件，我们在其中定义作业和作业的步骤。（如果还涉及到reader和writer也一样，那么的配置 reader 和 writer ，也包括在此文件。）
Context.xml - 在此文件中，我们将定义诸如作业存储库，作业启动程序和事务管理器之类的bean。
Tasklet类 - 在这个类中，我们将编写处理代码作业（在这种情况下，它显示一个简单的消息）
Launcher类 - 在此类中，我们将通过运行Job启动器来启动Batch Application。

jobConfig.xml

以下是我们的示例Spring Batch应用程序的配置文件。

<beans xmlns = "http://www.springframework.org/schema/beans"
   xmlns:batch = "http://www.springframework.org/schema/batch"
   xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation = "http://www.springframework.org/schema/batch
      http://www.springframework.org/schema/batch/spring-batch-2.2.xsd
      http://www.springframework.org/schema/beans
      http://www.springframework.org/schema/beans/spring-beans-3.2.xsd ">
   <import resource="context.xml" />      
   <!-- Defining a bean -->
   <bean id = "tasklet" class = "a_sample.MyTasklet" />  
   <!-- Defining a job-->
   <batch:job id = "helloWorldJob">  
      <!-- Defining a Step -->
      <batch:step id = "step1">
         <tasklet ref = "tasklet"/>   
      </batch:step>    
   </batch:job>  
</beans>

context.xml

以下是我们的Spring Batch应用程序的 context.xml 。

<beans xmlns = "http://www.springframework.org/schema/beans"
   xmlns:xsi = http://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation = "http://www.springframework.org/schema/beans
   http://www.springframework.org/schema/beans/spring-beans-3.2.xsd">  

   <bean id = "jobRepository"   
      class="org.springframework.batch.core.repository.support.MapJobRepositoryFactoryBean">
      <property name = "transactionManager" ref = "transactionManager" />
   </bean>     

   <bean id = "transactionManager"
      class = "org.springframework.batch.support.transaction.ResourcelessTransactionManager" />  
   <bean id = "jobLauncher"
      class = "org.springframework.batch.core.launch.support.SimpleJobLauncher">
      <property name = "jobRepository" ref = "jobRepository" />
   </bean>
</beans>

Tasklet.java

以下是Tasklet类，它显示一条简单的消息。

import org.springframework.batch.core.StepContribution;
import org.springframework.batch.core.scope.context.ChunkContext;
import org.springframework.batch.core.step.tasklet.Tasklet;
import org.springframework.batch.repeat.RepeatStatus;  

public class MyTasklet implements Tasklet {

   @Override
   public RepeatStatus execute(StepContribution arg0, ChunkContext arg1) throws Exception {  
      System.out.println("Hello This is a sample example of spring batch");
      return RepeatStatus.FINISHED;
   }
}

App.java

以下是启动批处理过程的代码。

import org.springframework.batch.core.Job;
import org.springframework.batch.core.JobExecution;
import org.springframework.batch.core.JobParameters;
import org.springframework.batch.core.launch.JobLauncher;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class App {
   public static void main(String[] args)throws Exception {

      // System.out.println("hello");
      String[] springConfig  =  {"a_sample/job_hello_world.xml"};  

      // Creating the application context object  
      ApplicationContext context = new ClassPathXmlApplicationContext(springConfig);

      // Creating the job launcher
      JobLauncher jobLauncher = (JobLauncher) context.getBean("jobLauncher");

      // Creating the job
      Job job = (Job) context.getBean("helloWorldJob");

      // Executing the JOB
      JobExecution execution = jobLauncher.run(job, new JobParameters());
      System.out.println("Exit Status : " + execution.getStatus());
   }    
}

执行时，上面的SpringBatch程序将产生以下输出 -

Apr 24, 2017 4:40:54 PM org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO:Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@2ef1e4fa: startup date [Mon Apr 24 16:40:54 IST 2017]; root of context hierarchy
Apr 24, 2017 4:40:54 PM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions INFO: Loading XML bean definitions  
Apr 24, 2017 4:40:54 PM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions  
INFO: Loading XML bean definitions
Apr 24, 2017 4:40:54 PM org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
Apr 24, 2017 4:40:55 PM org.springframework.batch.core.launch.support.SimpleJobLauncher afterPropertiesSet
INFO: No TaskExecutor has been set, defaulting to synchronous executor.
Apr 24, 2017 4:40:55 PM org.springframework.batch.core.launch.support.SimpleJobLauncher$1 run
INFO: Job: [FlowJob: [name=helloWorldJob]] launched with the following parameters: [{}]
Apr 24, 2017 4:40:55 PM org.springframework.batch.core.job.SimpleStepHandler handleStep INFO: Executing step: [step1]
Hello This is a sample example of spring batch
Apr 24, 2017 4:40:55 PM org.springframework.batch.core.launch.support.SimpleJobLauncher$1 run
INFO: Job: [FlowJob: [name=helloWorldJob]] completed with the following parameters: [{}] and the following status: [COMPLETED]
Exit Status : COMPLETED