package com.example.demo;

import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@EnableBatchProcessing
public class BatchSampleChunkApplication {

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

package com.example.demo.chunk;

import org.springframework.batch.core.configuration.annotation.StepScope;
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.stereotype.Component;
import lombok.extern.slf4j.Slf4j;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@Component
@StepScope
@Slf4j
public class SampleReader implements ItemReader<String> {
	Logger logger = LoggerFactory.getLogger(SampleReader.class);
	
	//配列
	private String[] input = {"Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"};

	private int index = 0;
	
	@Override
	public String read() throws Exception,UnexpectedInputException,ParseException,NonTransientResourceException{
		if (input.length > index) {
			//配列の文字列を取得
			String message = input[index++];
			logger.info("Read:{}",message);
			
			return message;
		}
		return null;
	}
}

package com.example.demo.chunk;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.batch.core.configuration.annotation.StepScope;
import org.springframework.batch.item.ItemProcessor;
import org.springframework.stereotype.Component;
import lombok.extern.slf4j.Slf4j;

@Component
@StepScope
@Slf4j
public class SampleProcessor implements ItemProcessor<String,String>{

	Logger logger = LoggerFactory.getLogger(SampleProcessor.class);
	
	@Override
	public String process(String item) throws Exception{
		
		//文字列の加工(小文字に変換)
		item = item.toLowerCase();
		logger.info("Processor:{}",item);
		return item;
	}
}

package com.example.demo.chunk;

import java.util.List;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.batch.core.configuration.annotation.StepScope;
import org.springframework.batch.item.ItemWriter;
import org.springframework.stereotype.Component;
import lombok.extern.slf4j.Slf4j;

@Component
@StepScope
@Slf4j
public class SampleWritter implements ItemWriter<String>{

	Logger logger = LoggerFactory.getLogger(SampleProcessor.class);
	
	@Override
	public void write(List<? extends String> items) throws Exception{
		logger.info("writer:{}",items);
		logger.info("=========");
	}
}

package com.example.demo.config;

import org.springframework.batch.core.Job;
import org.springframework.batch.core.Step;
import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing;
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.ItemProcessor;
import org.springframework.batch.item.ItemReader;
import org.springframework.batch.item.ItemWriter;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
@EnableBatchProcessing 
public class BatchConfig {

	//JobBuilderのFactoryクラス
	@Autowired
	private JobBuilderFactory jobBuilderFactory;
	
	//StepBuilderのFactoryクラス
	@Autowired
	private StepBuilderFactory stepBuilderFactory;
	
	@Autowired
	private ItemReader<String> reader;
	@Autowired
	private ItemProcessor<String, String> processor;
	@Autowired
	private ItemWriter<String> writer;
	
	// ChunkのStepを生成
	@Bean
	public Step chunkStep() {
		return stepBuilderFactory.get("SampleChunkStep")	//Builderの取得
			.<String, String>chunk(3)		//チャンクの設定
			.reader(reader) 			//readerセット
			.processor(processor) 		//processorセット
			.writer(writer) 			//writerセット
			.build(); 				//Stepの生成
	}
	
	// Jobを生成
	@Bean
	public Job chunkJob() throws Exception {
		return jobBuilderFactory.get("SampleChunkJob")	//Builderの取得
			.incrementer(new RunIdIncrementer())	//IDのインクリメント
			.start(chunkStep())				//最初のStep
			.build();					//Jobの生成
	}
}

: Started BatchSampleChunkApplication in 1.584 seconds (JVM running for 2.385)
: Running default command line with: []
: Job: [SimpleJob: [name=SampleChunkJob]] launched with the following
: Executing step: [SampleChunkStep]
: Read:Sunday
: Read:Monday
: Read:Tuesday
: Processor:sunday
: Processor:monday
: Processor:tuesday
: writer:[sunday, monday, tuesday]
: =========
: Read:Wednesday
: Read:Thursday
: Read:Friday
: Processor:wednesday
: Processor:thursday
: Processor:friday
: writer:[wednesday, thursday, friday]
: =========
: Read:Saturday
: Processor:saturday
: writer:[saturday]
: =========
: Step: [SampleChunkStep] executed in 40ms
: Job: [SimpleJob: [name=SampleChunkJob]] completed with the following parameters: [{run.id=1}] and the following status: [COMPLETED] in 56ms