Spring Batch入门程序

本章向您演示如何编辑一个基本的Spring Batch应用程序。 它将简单地执行一个tasklet来显示一条消息。

这个Spring Batch应用程序包含以下文件 -

• 配置文件 - 这是一个XML文件，在这个文件定义作业和作业的步骤(如果应用程序也包括读取器和写入器，那么读取器和写入器的配置也包含在这个文件中。)
• Context.xml - 在这个文件中，我们将定义像作业存储库，作业启动器和事务管理器的bean。
• Tasklet类 - 在这个类中，编写处理代码作业(在这个示例中，它显示一个简单的消息)
• Launcher类 - 在这个类中，通过运行Job启动器来启动批处理应用程序。

完整的项目目录结构如下所示 -

jobconfig.xml

以下是这个Spring Batch应用程序示例的配置文件。

<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 = "com.yiibai.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Spring Batch应用程序的context.xml文件内容。

<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>

MyTasklet.java

以下是显示简单消息的Tasklet类。

package com.yiibai;
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。

package com.yiibai;

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  =  {"context.xml", "jobconfig.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()); 
       }    
    }

在执行时，上面的SpringBatch程序将产生以下输出 -

四月 27, 2018 10:09:54 上午 org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@26a1ab54: startup date [Fri Apr 27 10:09:54 CST 2018]; root of context hierarchy
四月 27, 2018 10:09:54 上午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [context.xml]
四月 27, 2018 10:09:54 上午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [jobconfig.xml]
四月 27, 2018 10:09:54 上午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [context.xml]
四月 27, 2018 10:09:55 上午 org.springframework.batch.core.launch.support.SimpleJobLauncher afterPropertiesSet
信息: No TaskExecutor has been set, defaulting to synchronous executor.
四月 27, 2018 10:09:55 上午 org.springframework.batch.core.launch.support.SimpleJobLauncher run
信息: Job: [FlowJob: [name=helloWorldJob]] launched with the following parameters: [{}]
四月 27, 2018 10:09:55 上午 org.springframework.batch.core.job.SimpleStepHandler handleStep
信息: Executing step: [step1]
Hello This is a sample example of Spring Batch
四月 27, 2018 10:09:55 上午 org.springframework.batch.core.launch.support.SimpleJobLauncher run
信息: Job: [FlowJob: [name=helloWorldJob]] completed with the following parameters: [{}] and the following status: [COMPLETED]
Exit Status : COMPLETED

以下是纠正/补充内容：