21. ItemWriterAdapter

  배치 Job 안에서 이미 존재하는 DAO나 다른 서비스를 ItemWriter 안에서 사용하고자 할 때 위임 역할을 합니다. setTargetObject에 존재하는 서비스를 setTargetMethod에 호출하려는 메서드명을 적용합니다.

package io.springbatch.springbatchlecture;

import lombok.RequiredArgsConstructor;
import org.springframework.batch.core.*;
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.item.ItemReader;
import org.springframework.batch.item.NonTransientResourceException;
import org.springframework.batch.item.ParseException;
import org.springframework.batch.item.UnexpectedInputException;
import org.springframework.batch.item.adapter.ItemWriterAdapter;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@RequiredArgsConstructor
@Configuration
public class ItemWriterAdapterConfiguration {

    private final JobBuilderFactory jobBuilderFactory;
    private final StepBuilderFactory stepBuilderFactory;

    @Bean
    public Job job() throws Exception {
        return jobBuilderFactory.get("batchJob")
                .incrementer(new RunIdIncrementer())
                .start(step1())
                .build();
    }

    @Bean
    public Step step1() throws Exception {
        return stepBuilderFactory.get("step1")
                .<String, String>chunk(10)
                .reader(new ItemReader<String>() {
                    int i = 0;
                    @Override
                    public String read() throws Exception, UnexpectedInputException, ParseException, NonTransientResourceException {
                        i++;
                        return i > 10 ? null : "item" + i;
                    }
                })
                .writer(customItemWriter())
                .build();
    }



    @Bean
    public ItemWriterAdapter customItemWriter() {

        ItemWriterAdapter<String>  writer = new ItemWriterAdapter<>();
         writer.setTargetObject(customService());
         writer.setTargetMethod("joinCustomer");
        return  writer;
    }

    @Bean
    public CustomService customService() {
        return new CustomService();
    }
}

CustomService.java

package io.springbatch.springbatchlecture;

public class CustomService<T> {

    public void customWrite(T item){

        System.out.println(item);
    }
}

 

[참고자료]

인프런-스프링 배치 - Spring Boot 기반으로 개발하는 Spring Batch