[JAVA] I tried Spring Batch

Overview

I will keep a memorandum when using Spring Batch with STS. Mainly for myself. Spring Batch is a batch application framework based on the Spring Framework.

The development environment is as follows. OS : Windows 7 Home Edition 64bit Java : JavaSE 8 update 181 Spring Boot : 2.3.4 STS : 4.6.1

STS setup

For the STS setup, I referred to My memorandum.

Creating a project

Click Create new Spring Starter Project below.

Set the project.

Set the library reference.

Site info is set, no change.

The project is ready.

Notes

About Lombok

Only Lombok downloads the jar and Select and install the STS used in the installer. The installer can be downloaded from Lombok Official. Since Lombok refers to the project, Using annotations doesn't cause a compile error, getter / setter, constructor is not automatically generated, Attempting to call them will result in a compilation error. Since getter / setter etc. need to be automatically generated by the IDE, You also need to install it on STS.

Installing the Oracle Driver

DB is not used in this article, The configuration of Spring Boot + Spring Batch assumes the use of DB. Therefore, in application.properties and application.yml DB connection information is not listed, In the first place, there is no Oracle Driver When you run the application Cannot run with error that __datasource is required. __ Therefore, to Oracle that was set up on the PC that was confirmed to work I am referencing the library so that I can connect. Also, it can be executed without starting __DB at runtime __. If you have a library and you have a configuration and settings that try to connect to the DB schema That's OK.

Creating a batch application

Spring Batch official get started is here. In the above case, it is a specification to execute the created jar and load the csv data into the DB table.

In this article, I'll try scheduling batch processing without using cron. I referred to Spring Batch scheduling tasks @Scheduled documentation.

As an example, let's create a bean and implement a process to log its contents. Refer to Lombok to omit the variable declaration for log output and the boilerplate of the Bean class.

The implemented class is as follows.

First, the class with @SpringBootApplication, This class is specified at runtime.

`BatchSampleApplication.java`


package jp.co.illmatics;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class BatchSampleApplication {

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

}

This is the main routine for batch processing. By specifying @EnableScheduling Batch scheduling is now possible The method that specified @Scheduled cron = "${cron.pattern1}" It will be executed at the timing specified in.

`Batch.java`


package jp.co.illmatics;

import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.annotation.Scheduled;

import jp.co.illmatics.bean.Member;
import jp.co.illmatics.enumeration.VoicePart;
import lombok.extern.slf4j.Slf4j;

@Configuration
@EnableScheduling
@Slf4j
public class Batch {

	private String firstName = "Dummy";
	private String familyName = "Family";
	private String part = VoicePart.LEAD_VOCAL.toString();
	private String birthday = "1991/01/01";

	@Scheduled(cron = "${cron.pattern1}")
	public void execute() {
		Member member = new Member(firstName, familyName, part, birthday);
		log.info("member = " + member.toString());
	}

}

This is a resource file. Use the key cron.pattern1 to set the execution timing of batch processing It is specified every 0 seconds per minute. Please check the Official API documentation for the format.

`application.properties`


spring.datasource.driver-class-name=oracle.jdbc.driver.OracleDriver
spring.datasource.url=jdbc:oracle:thin:@localhost:1521:XE
spring.datasource.username=xxxxxx
spring.datasource.password=xxxxxx
spring.jpa.database-platform=org.hibernate.dialect.Oracle10gDialect
spring.jpa.show-sql=true

cron.pattern1: 0 * * * * *

A bean for test data. It is validated using Bean Validation. Among them, I implemented @ExistsInVoicePrat as a custom validation.

`Member.java`


package jp.co.illmatics.bean;

import javax.validation.constraints.NotEmpty;

import org.springframework.format.annotation.DateTimeFormat;

import jp.co.illmatics.validator.annotation.ExistsInVoicePart;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.extern.slf4j.Slf4j;

@Data
@AllArgsConstructor
public class Member {

	@NotEmpty(message = "Input first name.")
	private String firstName;

	@NotEmpty(message = "Input family name.")
	private String familyName;

	@ExistsInVoicePart
	private String part;

	@DateTimeFormat(pattern = "yyyy/MM/dd")
	private String birthday;

}

Annotation for custom validation.

`ExistsInVoicePart.java`


package jp.co.illmatics.validator.annotation;

import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

import java.lang.annotation.Retention;
import java.lang.annotation.Target;

import javax.validation.Constraint;
import javax.validation.Payload;

import jp.co.illmatics.validator.VoicePartValidator;

@Constraint(validatedBy = {VoicePartValidator.class})
@Target({FIELD})
@Retention(RUNTIME)
public @interface ExistsInVoicePart {

	String message() default "Input voice part.";
    Class<?>[] groups() default {};
    Class<? extends Payload>[] payload() default {};
    
    @Target({FIELD})
    @Retention(RUNTIME)
    public @interface List {
        ExistsInVoicePart[] value();
    }

}

An Enum for a custom validator.

`VoicePart.java`


package jp.co.illmatics.enumeration;

public enum VoicePart {

	LEAD_VOCAL("lead vocal"),
	BEATBOXER("beatboxer"),
	BASS("bass"),
	OTHERS("others");

    @SuppressWarnings("unused")
	private final String name;
 
    private VoicePart(String name) {
        this.name = name;
    }
}

Custom validator.

`VoicePartValidator.java`


package jp.co.illmatics.validator;

import java.util.Arrays;

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;

import jp.co.illmatics.enumeration.VoicePart;
import jp.co.illmatics.validator.annotation.ExistsInVoicePart;

public class VoicePartValidator implements ConstraintValidator<ExistsInVoicePart, String> {

	public void initialize(ExistsInVoicePart annotation) {
	}

	@Override
	public boolean isValid(String value, ConstraintValidatorContext context) {
		return Arrays.stream(VoicePart.values()).filter(part -> part.name().equals(value)).findFirst().isPresent();
	}
}

Operation check

Right click on BatchSampleApplication.java, Run as Spring Boot Application.

It runs every 0 seconds every minute. 実行結果.PNG

that's all. Until the end Thank you for reading.