SpringBatch 字段封装解析txt文件

需求：将txt文件内容解析 所有地区相关信息汇总拼接到User对象的address里

文件：users2.txt

1#dadfei#18#广东#广州#天河区
2#erfei#19#广东#广州#天河区
3#sanfei#17#广东#广州#天河区
4#sifei#16#广东#广州#天河区
5#wufei#15#广东#广州#天河区

对象：User.class

@Data
public class User {
    private Long id;
    private String name;
    private int age;
    private String address;

}

解决：采用字段映射方式

实现：FieldSetMapper

public interface FieldSetMapper<T> {
    T mapFieldSet(FieldSet var1) throws BindException;
}

在当前场景下 上述代码块的泛型T是User

上述代码块的 FieldSet 可以理解为手动封装数据

封装示例：

package com.springBatch.demo.flatFileReaderJob;

import org.springframework.batch.item.file.mapping.FieldSetMapper;
import org.springframework.batch.item.file.transform.FieldSet;
import org.springframework.validation.BindException;

//将解析出来的数据进行自定义封装
public class UserFieldSetMapper implements FieldSetMapper<User> {
    @Override
    public User mapFieldSet(FieldSet fieldSet) throws BindException {
//获取解析的数据
        Long id = fieldSet.readLong("id");
        String name = fieldSet.readString("name");
        int age = fieldSet.readInt("age");
//对解析的数据进行拼接
        String address = fieldSet.readString("province") + fieldSet.readString("city") + fieldSet.readString("area");
//将数据封装为对象返回
        User user = new User();
        user.setId(id);
        user.setName(name);
        user.setAge(age);
        user.setAddress(address);
        return user;
    }
}

实现代码：

package com.springBatch.demo.flatFileReaderJob;

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.*;
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 FlatReaderJob {
    @Autowired
    private JobBuilderFactory jobBuilderFactory;
    @Autowired
    private StepBuilderFactory stepBuilderFactory;
    // first  job--step--chunk--itemreader --writer

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

//这里将封装注入
    @Bean
    public UserFieldSetMapper fieldSetMapper() {
        return new UserFieldSetMapper();
    }

    @Bean
    public FlatFileItemReader<User> itemReader() {
        return new FlatFileItemReaderBuilder<User>()
                .name("user-itemReader")
                .resource(new ClassPathResource("users2.txt"))
                .delimited().delimiter("#")
                .names("id","name","age","province","city","area")
//                .targetType(User.class) //自动封装
                .fieldSetMapper(fieldSetMapper())
                .build();
    }

    @Bean
    public Step step() {
        return stepBuilderFactory.get("step1")
                .<User,User>chunk(1)
                .reader(itemReader())
                .writer(itemWriter())
                .build();
    }

    @Bean
    public Job job() {
        return jobBuilderFactory.get("flat-reader-job")
                .start(step())
                .build();
    }

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

结果：

User(id=1, name=dadfei, age=18, address=广东广州天河区)
User(id=2, name=erfei, age=19, address=广东广州天河区)
User(id=3, name=sanfei, age=17, address=广东广州天河区)
User(id=4, name=sifei, age=16, address=广东广州天河区)
User(id=5, name=wufei, age=15, address=广东广州天河区)