SpringBatch的ItemWriterDemo

Posted 2021-03-05 syue

跟着视频写的一个小Demo

目录结构：

 

 

MyWriter.class

package com.practice.itemwriter;

import org.springframework.batch.item.ItemWriter;
import org.springframework.stereotype.Component;

import java.util.List;

@Component("myWriter")
public class MyWriter   implements ItemWriter<String>
{
    @Override
    public void write(List<? extends String> items) throws Exception {
        System.out.println(items.size());
        for(String str:items){
            System.out.println(str);
        }
    }
}

ItemWriterDemo.class

package com.practice.itemwriter;

import org.springframework.batch.core.Job;
import org.springframework.batch.core.Step;
import org.springframework.batch.core.configuration.annotation.JobBuilderFactory;
import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
import org.springframework.batch.item.ItemReader;
import org.springframework.batch.item.ItemWriter;
import org.springframework.batch.item.support.ListItemReader;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.util.ArrayList;
import java.util.List;

@Configuration
public class ItemWriterDemo {
    @Autowired
    private JobBuilderFactory jobBuilderFactory;

    @Autowired
    private StepBuilderFactory stepBuilderFactory;
    @Autowired
    @Qualifier("myWriter")
    private  ItemWriter<String> myWriter;
    @Bean
    public Job itemWriterDemoJob(){
        return jobBuilderFactory.get("itemWriterDemoJob").start(itemWriterDemoStep()).build();
    }
    @Bean
    public Step itemWriterDemoStep() {

        return stepBuilderFactory.get("itemWriterDemoStep")
                .<String,String>chunk(10).reader(myRead()).writer(myWriter).build();
    }

    public ItemReader<String> myRead() {
        List<String> items = new ArrayList<>();
        for(int i = 0;i<=50;i++){
            items.add("java"+i);
        }
        return new ListItemReader<String>(items);
    }
}

DemoApplication

package com.practice.itemwriter;

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

@SpringBootApplication
@EnableBatchProcessing
public class DemoApplication {

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

}

正常输出：