Just Go Through .....: # Spring Batch Job #

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.
Description: boot-23_1

Lets Begin-

The project will be as follows-
Description: boot-23_2

<?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">

<groupId>com.javainuse</groupId>

<artifactId>springboot-batch</artifactId>

<name>SpringBatch</name>

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

<groupId>org.springframework.boot</groupId>

<artifactId>spring-boot-starter-parent</artifactId>

<version>1.4.3.RELEASE</version>

</parent>

<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>

<java.version>1.8</java.version>

</properties>

<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>

<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.
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;