Spring Batch TaskScheduler example（九）

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;@Componentpublic 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 usetask: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/batchhttp://www.springframework.org/schema/batch/spring-batch-2.2.xsdhttp://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsdhttp://www.springframework.org/schema/contexthttp://www.springframework.org/schema/context/spring-context-3.2.xsdhttp://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">  <beanclass="org.springframework.batch.item.file.transform.DelimitedLineTokenizer"><property name="names" value="id,impressions" />  </bean></property><property name="fieldSetMapper">  <beanclass="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 2013Jul 28, 2013 11:20:30 AM org.springframework.batch.core.launch.support.SimpleJobLauncher$1 runINFO: 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 handleStepINFO: Executing step: [step1]writer...3Report [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 runINFO: 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 : COMPLETEDSun Jul 28 11:20:35 MYT 2013Jul 28, 2013 11:20:35 AM org.springframework.batch.core.launch.support.SimpleJobLauncher$1 runINFO: 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 handleStepINFO: Executing step: [step1]writer...3Report [id=1, Impressions=139,237]Report [id=2, Impressions=500,657]Report [id=3, Impressions=342,100]Exit Status : COMPLETEDJul 28, 2013 11:20:35 AM org.springframework.batch.core.launch.support.SimpleJobLauncher$1 runINFO: Job: [FlowJob: [name=reportJob]] completed with the following parameters: [{date=Sun Jul 28 11:20:35 MYT 2013}] and the following status: [COMPLETED]......