How to use Spring Batch Restartable Function

http://javasampleapproach.com/spring-framework/spring-batch/use-spring-batch-restartable-functio #more-2511
How to use Spring Batch Restartable Function

SpringBatch provides a restartable mechanics with a Job, in the How to use Spring Batch Restartable Function tutorial, JavaSampleApproach will present to you the principle of this function with SpringBoot.

Related Post:
1. How to start with Spring Batch using Spring Boot – Java Config
at: http://javasampleapproach.com/spring-framework/spring-boot/start-spring-batch-using-spring-boot

2. Spring Batch XML Config by Spring Boot
at: http://javasampleapproach.com/spring-framework/spring-batch/spring-batch-xml-config-spring-boot

3. Spring Batch Job with Parallel Steps
at: http://javasampleapproach.com/spring-framework/spring-batch/spring-batch-job-parallel-steps

4. How to import CSV data to PostgreSQL Database using Spring Batch Job
at: http://javasampleapproach.com/spring-framework/how-to-import-csv-data-to-postgresql-database-using-spring-batch-job

I. Technologies

– Java 1.8
– Maven 3.3.9
– Spring Boot: 1.4.3.RELEASE
– Spring Tool Suite – Version 3.8.1.RELEASE

II. Overview

Create a Batch Job which has a simple step with a Reader & Writer.
Reader reads a list file-paths then pass them to a Writer. The Write uses file paths to process content of each file.
With created JOB, test a restartable function base on FileNotFound Error.
Note: a Batch Job is created with restartable default. Spring Batch also supports configuration to prevent the restartable function.

1. Project Structure
2. Step to do

– Create SpringBoot project
– Create simple step
– Config a Batch Job
– Create a Job Launch controller
– Config Batch Job Database
– Enable Batch Job
– Scenario Test

III. Spring Batch Restartable Practices

1. Create a SpringBoot project
Open Spring Tool Suite, on main menu, choose File-New-Spring Starter Project, input project info. Press Next then Finish, a Spring Boot project will be created successfully.

– Open pom.xml file, add Web MVC, PostgreSQL and Spring Batch dependencies

2. Create classes Reader & Writer for simple step
- Create a Reader class
- Create a Writer class

3. Config a Batch Job
Config a Simple Batch Job

4. Create a Job Launch controller
– Create a simple Controller for Job Launching.

5. Config Batch Job Database
Config DataBase’s info for Spring Batch:
spring.datasource.url=jdbc:postgresql://localhost/testdb
spring.datasource.username=postgres
spring.datasource.password=123
spring.batch.job.enabled=false

6. Enable Batch Job
In main class of Spring Boot project, use @EnableBatchProcessing to enable Spring Batch.

7. Scenario Test
– Build & Run the Spring Boot Batch Job.
The Reader will forward a file name: C:\\readfile\\1.txt to Writer. Delete a file C:\\readfile\\1.txt, then makes a launch request: http://localhost:8080/launchjob
A Job Instance is created with Empty Parameters:


IV. Prevent Restartable

SpringBatch also supports a config to prevent restartable ability of a Job even if a Job Instance’s Execution with FAIL status.
How to configure? Just use a little code strong.preventRestart(), details with BatchConfig class

V. Sourcecode
SpringBatchRestartableFunction