16. ItemReaderAdapter

  배치 Job 안에서 이미 존재하는 DAO나 다른 서비스를 ItemReader 안에서 사용하고자 할 때 위임 역할을 합니다. setTargetObject에 존재하는 서비스를 setTargetMethod에 호출하려는 메서드명을 설정하면 됩니다.

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.ItemWriter;
import org.springframework.batch.item.adapter.ItemReaderAdapter;
import org.springframework.batch.item.database.*;
import org.springframework.batch.item.database.builder.JdbcCursorItemReaderBuilder;
import org.springframework.batch.item.database.builder.JdbcPagingItemReaderBuilder;
import org.springframework.batch.item.database.builder.JpaCursorItemReaderBuilder;
import org.springframework.batch.item.database.builder.JpaPagingItemReaderBuilder;
import org.springframework.batch.item.database.support.SqlPagingQueryProviderFactoryBean;
import org.springframework.batch.item.json.JacksonJsonObjectReader;
import org.springframework.batch.item.json.JsonItemReader;
import org.springframework.batch.item.json.builder.JsonItemReaderBuilder;
import org.springframework.batch.item.xml.StaxEventItemReader;
import org.springframework.batch.item.xml.builder.StaxEventItemReaderBuilder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.CustomAutowireConfigurer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.ClassPathResource;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.oxm.xstream.XStreamMarshaller;

import javax.persistence.EntityManagerFactory;
import javax.sql.DataSource;
import java.sql.Types;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

@RequiredArgsConstructor
@Configuration
public class ItemReaderAdapterConfiguration {

    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(customItemReader())
                .writer(customItemWriter())
                .build();
    }

    @Bean
    public ItemReaderAdapter customItemReader() {

        ItemReaderAdapter reader = new ItemReaderAdapter();
        reader.setTargetObject(customService());
        reader.setTargetMethod("joinCustomer");

        return reader;
    }

    private CustomService<String> customService() {
        return new CustomService<>();
    }

    @Bean
    public ItemWriter<String> customItemWriter() {
        return items -> {
                System.out.println(items);
        };
    }
}

CustomService.java

package io.springbatch.springbatchlecture;

public class CustomService<T> {

    private int cnt = 0;

    public T joinCustomer(){
        return (T)("item" + cnt++);
    }
}

 

[참고자료]

인프런-스프링 배치 - Spring Boot 기반으로 개발하는 Spring Batch