Spring Batch + Spring TaskScheduler example

In this tutorial, we will show you how to use Spring TaskScheduler to schedule a batch job to run every 5 seconds.

Tools and libraries used

1. Maven 3

2. Eclipse 4.2

3. JDK 1.6

4. Spring Core 3.2.2.RELEASE

5. Spring Batch 2.2.0.RELEASE

1. Project Directory Structure

A standard Maven project.

2. Spring TaskScheduler

Spring 3.0 introduces a TaskScheduler for scheduling tasks. It’s part of the Spring-Core, no need to declare an extra dependency.

  <task:scheduled-tasks>
	<task:scheduled ref="runScheduler" method="run" fixed-delay="5000" />
  </task:scheduled-tasks>
  <task:scheduled-tasks>
	<task:scheduled ref="runScheduler" method="run" cron="*/5 * * * * *" />
  </task:scheduled-tasks>

The TaskScheduler will schedule to run below bean.

RunScheduler.java

package com.mkyong;
import java.util.Date;
import org.springframework.batch.core.Job;
import org.springframework.batch.core.JobExecution;
import org.springframework.batch.core.JobParameters;
import org.springframework.batch.core.JobParametersBuilder;
import org.springframework.batch.core.launch.JobLauncher;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
@Component
public class RunScheduler {
  @Autowired
  private JobLauncher jobLauncher;
  @Autowired
  private Job job;
  public void run() {
    try {
	String dateParam = new Date().toString();
	JobParameters param = 
	  new JobParametersBuilder().addString("date", dateParam).toJobParameters();
	System.out.println(dateParam);
	JobExecution execution = jobLauncher.run(job, param);
	System.out.println("Exit Status : " + execution.getStatus());
    } catch (Exception e) {
	e.printStackTrace();

P.S JobParamater need to be unique each time a batch job to run, for testing purpose, we just pass in a new Date() everything running the job.

3. Spring Batch Jobs

This job is just reading a csv file and display the value via a custom writer. Refer to the end of the file, we use task:scheduled-tasks to run this batch job every 5 seconds.

resources/spring/batch/jobs/job-report.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:batch="http://www.springframework.org/schema/batch"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:task="http://www.springframework.org/schema/task" 
	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
	http://www.springframework.org/schema/context
	http://www.springframework.org/schema/context/spring-context-3.2.xsd
	http://www.springframework.org/schema/task
        http://www.springframework.org/schema/task/spring-task-3.2.xsd
	">
  <context:component-scan base-package="com.mkyong" />
  <!-- job context -->
  <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>
  <!-- job context -->
  <bean id="report" class="com.mkyong.model.Report" scope="prototype" />
  <bean id="customWriter" class="com.mkyong.writers.CustomWriter" />
  <batch:job id="reportJob">
	<batch:step id="step1">
	  <batch:tasklet>
		<batch:chunk reader="cvsFileItemReader" writer="customWriter"
			commit-interval="10">
		</batch:chunk>
	  </batch:tasklet>
	</batch:step>
   </batch:job>
  <bean id="cvsFileItemReader" 
        class="org.springframework.batch.item.file.FlatFileItemReader">
	<!-- Read a csv file -->
	<property name="resource" value="classpath:cvs/input/report.csv" />
	<property name="lineMapper">
	  <bean class="org.springframework.batch.item.file.mapping.DefaultLineMapper">
		<property name="lineTokenizer">
		  <bean
			class="org.springframework.batch.item.file.transform.DelimitedLineTokenizer">
			<property name="names" value="id,impressions" />
		  </bean>
		</property>
		<property name="fieldSetMapper">
		  <bean
			class="org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper">
			<property name="prototypeBeanName" value="report" />
		  </bean>
		</property>
	  </bean>
	</property>
  </bean>
  <bean id="runScheduler" class="com.mkyong.RunScheduler" />
  <!-- Run every 5 seconds -->
  <task:scheduled-tasks>
    <!-- 
	<task:scheduled ref="runScheduler" method="run" fixed-delay="5000" /> 
    -->
	<task:scheduled ref="runScheduler" method="run" cron="*/5 * * * * *" />
   </task:scheduled-tasks>
</beans>

report.csv

1,"139,237"
2,"500,657"
3,"342,100"

CustomWriter.java

package com.mkyong.writers;
import java.util.List;
import org.springframework.batch.item.ItemWriter;
import com.mkyong.model.Report;
public class CustomWriter implements ItemWriter<Report> {
  @Override
  public void write(List<? extends Report> items) throws Exception {
	System.out.println("writer..." + items.size());		
	for(Report item : items){
		System.out.println(item);

4. Run It

Loads the Spring application context, the scheduler will be run automatically.

App.java

package com.mkyong;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class App {
  public static void main(String[] args) {
	String springConfig = "spring/batch/jobs/job-report.xml";
	ApplicationContext context = new ClassPathXmlApplicationContext(springConfig);

Output, it prints the csv content every 5 seconds.

......
Sun Jul 28 11:20:30 MYT 2013
Jul 28, 2013 11:20:30 AM org.springframework.batch.core.launch.support.SimpleJobLauncher$1 run
INFO: Job: [FlowJob: [name=reportJob]] launched with the following parameters: [{date=Sun Jul 28 11:20:30 MYT 2013}]
Jul 28, 2013 11:20:30 AM org.springframework.batch.core.job.SimpleStepHandler handleStep
INFO: Executing step: [step1]
writer...3
Report [id=1, Impressions=139,237]
Report [id=2, Impressions=500,657]
Report [id=3, Impressions=342,100]
Jul 28, 2013 11:20:30 AM org.springframework.batch.core.launch.support.SimpleJobLauncher$1 run
INFO: Job: [FlowJob: [name=reportJob]] completed with the following parameters: [{date=Sun Jul 28 11:20:30 MYT 2013}] and the following status: [COMPLETED]
Exit Status : COMPLETED
Sun Jul 28 11:20:35 MYT 2013
Jul 28, 2013 11:20:35 AM org.springframework.batch.core.launch.support.SimpleJobLauncher$1 run
INFO: Job: [FlowJob: [name=reportJob]] launched with the following parameters: [{date=Sun Jul 28 11:20:35 MYT 2013}]
Jul 28, 2013 11:20:35 AM org.springframework.batch.core.job.SimpleStepHandler handleStep
INFO: Executing step: [step1]
writer...3
Report [id=1, Impressions=139,237]
Report [id=2, Impressions=500,657]
Report [id=3, Impressions=342,100]
Exit Status : COMPLETED
Jul 28, 2013 11:20:35 AM org.springframework.batch.core.launch.support.SimpleJobLauncher$1 run
INFO: Job: [FlowJob: [name=reportJob]] completed with the following parameters: [{date=Sun Jul 28 11:20:35 MYT 2013}] and the following status: [COMPLETED]
......

References

1. Spring – Schedululing a task.

2. Wiki : Cron

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