SpringBatch中ItemProcessor之适配器处理器

类型：ItemProcessorAdapter

定义： 真实开发中，很多校验逻辑已经有现成的了，那么做ItemProcessor处理的时候，可以直接使用。

举例： 现有逻辑，将user对象中的name转为大写，想在ItemProcessor中用起来。

package com.springBatch.demo.adapterJob;

public class UserServiceImpl {
    public User toUppeCase(User user) {
        user.setName(user.getName().toUpperCase());
        return user;
    }
}

user.txt

1##18
2##16
3#dafei#20
4#erfei#19
5#sanfei#17

代码实现：

package com.springBatch.demo.adapterJob;


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.item.ItemWriter;
import org.springframework.batch.item.adapter.ItemProcessorAdapter;
import org.springframework.batch.item.file.FlatFileItemReader;
import org.springframework.batch.item.file.builder.FlatFileItemReaderBuilder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.core.io.ClassPathResource;

import java.util.List;

@EnableBatchProcessing
@SpringBootApplication
public class adapterProcessorJob {

    @Autowired
    private JobBuilderFactory jobBuilderFactory;
    @Autowired
    private StepBuilderFactory stepBuilderFactory;

    //1.创建ItemWriter
    @Bean
    public ItemWriter<User> itemWriter() {
        return new ItemWriter<User>() {
            @Override
            public void write(List<? extends User> list) throws Exception {
                list.forEach(System.out::println);
            }
        };
    }


    //2.创建ItemReader-FlatFileItemReader-因为读取的是txt文件
    @Bean
    public FlatFileItemReader<User> itemReader() {
        return new FlatFileItemReaderBuilder<User>()
                .name("UserTxtItemReader")// 起个名字
                .resource(new ClassPathResource("user-validate.txt")) //源文件
                .delimited().delimiter("#")//分隔符
                .names("id","name","age")//分割后字段名字
                .targetType(User.class)//映射类型
                .build();
    }

    //3.1
    @Bean
    public UserServiceImpl userService() {
        return new UserServiceImpl();
    }

    //3.2 创建ItemProcessor
    @Bean
    public ItemProcessorAdapter<User,User> itemProcessorAdapter() {
        ItemProcessorAdapter<User, User> itemProcessorAdapter = new ItemProcessorAdapter<User, User>();
        itemProcessorAdapter.setTargetObject(userService());
        itemProcessorAdapter.setTargetMethod("toUppeCase");
        return itemProcessorAdapter;

    }

    //4.创建step
    @Bean
    public Step step() {
        return stepBuilderFactory.get("adapter-step")
                .<User, User>chunk(1)
                .reader(itemReader())
                .processor(itemProcessorAdapter())
                .writer(itemWriter())
                .build();
    }

    //5.创建job
    @Bean
    public Job job() {
        return jobBuilderFactory.get("adapter-job")
                .start(step())
                .build();
    }

    //6. 创建main方法
    public static void main(String[] args) {
        SpringApplication.run(adapterProcessorJob.class, args);
    }

}

结果展示：

User(id=1, name=, age=18)
User(id=2, name=, age=16)
User(id=3, name=DAFEI, age=20)
User(id=4, name=ERFEI, age=19)
User(id=5, name=SANFEI, age=17)