Spring Boot Batch Job + Scheduler Simple Example

In a previous post we had implemented a Spring Boot Hello World Application. In that the Batch Job got triggered by a REST API call. In this post we develop a simple Spring Boot Batch application where batch job gets triggered using a scheduler.
Consider the simple use case where the user wants to delete files from a particular location everyday at a particular time. We will schedule this batch job using the scheduler.

Spring Batch - Table Of Contents
Spring Batch Hello World example-Write data from csv to xml file 
Spring Boot Batch Simple example
Spring Batch - Difference between Step, Chunk and Tasklet
Spring Batch Tasklet - Hello World example
Spring Boot + Batch + Task Scheduler Example

Lets Begin-

The project will be as follows-

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>

	<groupId>com.javainuse</groupId>
	<artifactId>springboot-batch</artifactId>
	<version>0.0.1</version>
	<packaging>jar</packaging>

	<name>SpringBatch</name>
	<description>Spring Batch-Spring Boot</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>1.4.3.RELEASE</version>
		<relativePath /> <!-- lookup parent from repository -->
	</parent>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
		<java.version>1.8</java.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-batch</artifactId>
		</dependency>

	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>


</project>

Create a batch configuration class as below.

package com.javainuse.jobs;

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.Step;
import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing;
import org.springframework.batch.core.configuration.annotation.JobBuilderFactory;
import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
import org.springframework.batch.core.launch.support.RunIdIncrementer;
import org.springframework.batch.core.launch.support.SimpleJobLauncher;
import org.springframework.batch.core.repository.JobRepository;
import org.springframework.batch.core.repository.support.MapJobRepositoryFactoryBean;
import org.springframework.batch.support.transaction.ResourcelessTransactionManager;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.Resource;
import org.springframework.scheduling.annotation.Scheduled;

import com.javainuse.tasklet.FileDeletingTasklet;

@Configuration
@EnableBatchProcessing
public class ProcessMultiFilesJob {

	@Autowired
	private JobBuilderFactory jobBuilderFactory;

	@Autowired
	private StepBuilderFactory stepBuilderFactory;

	@Autowired
	private SimpleJobLauncher jobLauncher;

	@Value("file:C:\\inbox\\")
	private Resource directory;

	@Bean
	public ResourcelessTransactionManager transactionManager() {
		return new ResourcelessTransactionManager();
	}

	@Bean
	public MapJobRepositoryFactoryBean mapJobRepositoryFactory(ResourcelessTransactionManager txManager)
			throws Exception {

		MapJobRepositoryFactoryBean factory = new MapJobRepositoryFactoryBean(txManager);

		factory.afterPropertiesSet();

		return factory;
	}

	@Bean
	public JobRepository jobRepository(MapJobRepositoryFactoryBean factory) throws Exception {

		return factory.getObject();

	}

	@Scheduled(cron = "*/5 * * * * *")
	public void perform() throws Exception {

		System.out.println("Job Started at :" + new Date());

		JobParameters param = new JobParametersBuilder().addString("JobID", String.valueOf(System.currentTimeMillis()))
				.toJobParameters();

		JobExecution execution = jobLauncher.run(readFiles(), param);

		System.out.println("Job finished with status :" + execution.getStatus());
	}

	@Bean
	public Job readFiles() {
		return jobBuilderFactory.get("readFiles").incrementer(new RunIdIncrementer()).flow(step1()).end().build();
	}

	@Bean
	public Step step1() {
		return stepBuilderFactory.get("step1").tasklet(fileDeletingTasklet()).build();
	}

	@Bean
	public FileDeletingTasklet fileDeletingTasklet() {
		FileDeletingTasklet tasklet = new FileDeletingTasklet();
		tasklet.setDirectory(directory);
		return tasklet;
	}

	@Bean
	public SimpleJobLauncher jobLauncher(JobRepository jobRepository) {
		SimpleJobLauncher launcher = new SimpleJobLauncher();
		launcher.setJobRepository(jobRepository);
		return launcher;
	}
}

In the above configuration, we get the reference of the configured JobLauncher through autowired injection. Run the JobLauncher with passing job bean and custom job parameter.
Cron expression can be generated at Cron Expression Generator.
Next define the Tasklet as follows-

package com.javainuse.jobs;

import java.util.Date;

import org.springframework.batch.core.Job;
import org.springframework.cbatch.core.JobExecution;
import org.springframework.batch.core.JobParameters;
import org.springframework.batch.core.JobParametersBuilder;
import org.springframework.batch.core.Step;
import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing;
import org.springframework.batch.core.configuration.annotation.JobBuilderFactory;
import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
import org.springframework.batch.core.launch.support.RunIdIncrementer;
import org.springframework.batch.core.launch.support.SimpleJobLauncher;
import org.springframework.batch.core.repository.JobRepository;
import org.springframework.batch.core.repository.support.MapJobRepositoryFactoryBean;
import org.springframework.batch.support.transaction.ResourcelessTransactionManager;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.Resource;
import org.springframework.scheduling.annotation.Scheduled;

import com.javainuse.tasklet.FileDeletingTasklet;

@Configuration
@EnableBatchProcessing
public class ProcessMultiFilesJob {

	@Autowired
	private JobBuilderFactory jobBuilderFactory;
	@Autowired
	private StepBuilderFactory stepBuilderFactory;

	@Autowired
	private SimpleJobLauncher jobLauncher;

	@Value("file:C:\\inbox\\")
	private Resource directory;

	@Bean
	public ResourcelessTransactionManager transactionManager() {
		
		return new ResourcelessTransactionManager();
	
	}

	@Bean
	public MapJobRepositoryFactoryBean mapJobRepositoryFactory(ResourcelessTransactionManager txManager)
			throws Exception {

		MapJobRepositoryFactoryBean factory = new MapJobRepositoryFactoryBean(txManager);

		factory.afterPropertiesSet();

		return factory;
	}

	@Bean
	public JobRepository jobRepository(MapJobRepositoryFactoryBean factory) throws Exception {
		return factory.getObject();
	}

	@Scheduled(cron = "*/5 * * * * *")
	public void perform() throws Exception {

		System.out.println("Job Started at :" + new Date());

		JobParameters param = new JobParametersBuilder().addString("JobID", String.valueOf(System.currentTimeMillis()))
				.toJobParameters();

		JobExecution execution = jobLauncher.run(readFiles(), param);

		System.out.println("Job finished with status :" + execution.getStatus());
	}

	@Bean
	public Job readFiles() {
		return jobBuilderFactory.get("readFiles").incrementer(new RunIdIncrementer()).flow(step1()).end().build();
	}

	@Bean
	public Step step1() {
		return stepBuilderFactory.get("step1").tasklet(fileDeletingTasklet()).build();
	}

	@Bean
	public FileDeletingTasklet fileDeletingTasklet() {
		FileDeletingTasklet tasklet = new FileDeletingTasklet();
		tasklet.setDirectory(directory);
		return tasklet;
	}

	@Bean
	public SimpleJobLauncher jobLauncher(JobRepository jobRepository) {
		SimpleJobLauncher launcher = new SimpleJobLauncher();
		launcher.setJobRepository(jobRepository);
		return launcher;
	}
}

In the application.properties, add the following property which tells the Spring Boot Application to not start the Batch Job on Application startup. Define the class implementing the spring batch ItemProcessor interface as follows-

spring.batch.job.enabled=false

Run the following Spring Boot class to start our application

package com.javainuse;

import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)
@EnableBatchProcessing
public class SpringBatchApplication {

	public static void main(String[] args) {
		SpringApplication.run(SpringBatchApplication.class, args);
	}
}

The files from the specified folder location get deleted each time the scheduler runs. In our case every 5 seconds.

Download Source Code

Download it -
Spring Boot + Batch Hello World Example

See Also
Spring Boot Hello World Application- Create simple controller and jsp view using Maven
Spring Boot Tutorial-Spring Data JPA
Spring Boot + Simple Security Configuration
Pagination using Spring Boot Simple Example
Spring Boot + ActiveMQ Hello world Example
Spring Boot + Swagger Example Hello World Example
Spring Boot + Swagger- Understanding the various Swagger Annotations
Spring Boot Main Menu
Spring Boot Interview Questions