[Spring Batch] batch process : 테이블 to 테이블

1. 테이블 생성

BeforeEntity, BeforeRepository

@Data
@Entity
public class BeforeEntity {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private String username;
}

@Repository
public interface BeforeRepository extends JpaRepository<BeforeEntity, Long> {
}

AfterEntity, AfterRepository

@Data
@Entity
public class AfterEntity {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private String username;
}

@Repository
public interface AfterRepository extends JpaRepository<AfterEntity, Long> {
}

 

테이블 생성 확인

 

테이블에 실습 데이터 삽입

 

Spring Batch 모식도

 

하나의 배치 Job을 정의할 클래스 FirstBatch생성 및 Jop, Step, ItemReader, ItemProcessor, ItemWriter 순으로 작성

 

Job

@Configuration
@RequiredArgsConstructor
public class FirstBatch {

    private final JobRepository jobRepository;
    private final PlatformTransactionManager platformTransactionManager;
    private final AfterRepository afterRepository;
    private final BeforeRepository beforeRepository;

    @Bean
    public Job firstJob() {
        return new JobBuilder("firstJob", jobRepository)
                .start(firstStep())
                .build();
    }

}

 

Setp

@Bean
public Step firstStep(){
    return new StepBuilder("firstStep", jobRepository)
            .<BeforeEntity, AfterEntity> chunk(10, platformTransactionManager)
            .reader(beforeReader())
            .processor(middleProcessor())
            .writer(afterWriter())
            .build();
}

 

ItemReader

//  JPA를 통한 쿼리를 수행하기 때문에 RepositoryItemReader를 사용
    @Bean
    public RepositoryItemReader<BeforeEntity> beforeReader() {
        return new RepositoryItemReaderBuilder<BeforeEntity>()
                .name("beforeReader")
                .pageSize(10)
                .methodName("findAll")
                .repository(beforeRepository)
                .sorts(Map.of("id", Sort.Direction.ASC))
                .build();
    }

 

ItemProcessor

@Bean
public ItemProcessor<BeforeEntity, AfterEntity> middleProcessor() {

    return new ItemProcessor<BeforeEntity, AfterEntity>() {

        @Override
        public AfterEntity process(BeforeEntity item) throws Exception {

            AfterEntity afterEntity = new AfterEntity();
            afterEntity.setUsername(item.getUsername());

            return afterEntity;
        }
    };
}

 

ItemWriter

@Bean
public RepositoryItemWriter<AfterEntity> afterWriter() {
    return new RepositoryItemWriterBuilder<AfterEntity>()
            .repository(afterRepository)
            .methodName("save")
            .build();
}

 

FirstBatch 전체코드

@Configuration
@RequiredArgsConstructor
public class FirstBatch {

    private final JobRepository jobRepository;
    private final PlatformTransactionManager platformTransactionManager;
    private final AfterRepository afterRepository;
    private final BeforeRepository beforeRepository;

    @Bean
    public Job firstJob() {
        return new JobBuilder("firstJob", jobRepository)
                .start(firstStep())
                .build();
    }

    @Bean
    public Step firstStep(){
        return new StepBuilder("firstStep", jobRepository)
                .<BeforeEntity, AfterEntity> chunk(10, platformTransactionManager)
                .reader(beforeReader())
                .processor(middleProcessor())
                .writer(afterWriter())
                .build();
    }

//  JPA를 통한 쿼리를 수행하기 때문에 RepositoryItemReader를 사용
    @Bean
    public RepositoryItemReader<BeforeEntity> beforeReader() {
        return new RepositoryItemReaderBuilder<BeforeEntity>()
                .name("beforeReader")
                .pageSize(10)
                .methodName("findAll")
                .repository(beforeRepository)
                .sorts(Map.of("id", Sort.Direction.ASC))
                .build();
    }

    @Bean
    public ItemProcessor<BeforeEntity, AfterEntity> middleProcessor() {

        return new ItemProcessor<BeforeEntity, AfterEntity>() {

            @Override
            public AfterEntity process(BeforeEntity item) throws Exception {

                AfterEntity afterEntity = new AfterEntity();
                afterEntity.setUsername(item.getUsername());

                return afterEntity;
            }
        };
    }

    @Bean
    public RepositoryItemWriter<AfterEntity> afterWriter() {
        return new RepositoryItemWriterBuilder<AfterEntity>()
                .repository(afterRepository)
                .methodName("save")
                .build();
    }
}