SpringBatch中ItemProcessor使用一

两套逻辑：默认处理器、自定义处理器

默认：校验处理器、适配器处理器、脚本处理器、组合处理器。

校验参数处理器-validatingItemProcessor

操作文件：user-validate.txt

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

目标：校验上述文档中名字不能为空 如果为空 提示参数不合法

实现：第一步：导入依赖

<dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-validation</artifactId>
    </dependency>

第二步创建实体类：

package com.springBatch.demo.processorJob;

import lombok.Data;
import javax.validation.constraints.NotBlank;

@Data
public class User {
    private Long id;
    @NotBlank(message = "用户名不能为空或null")
    private String name;
    private int age;
}

第三步：代码实现

package com.springBatch.demo.processorJob;

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.file.FlatFileItemReader;
import org.springframework.batch.item.file.builder.FlatFileItemReaderBuilder;
import org.springframework.batch.item.validator.BeanValidatingItemProcessor;
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 javax.swing.*;
import java.util.List;

@EnableBatchProcessing
@SpringBootApplication
public class ProcessorJob {

    @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. 创建ItemProcessor
    @Bean
    public BeanValidatingItemProcessor<User> beanValidatingItemProcessor() {
        BeanValidatingItemProcessor<User> itemProcessor = new BeanValidatingItemProcessor<>();
        itemProcessor.setFilter(true);//不满足条件的数据直接抛弃  具体的判断在实体类User中已经使用注解NotBlank实现
        return itemProcessor;

    }

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

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

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

}

第四步：结果展示

User(id=3, name=dafei, age=20)
User(id=4, name=erfei, age=19)
User(id=5, name=sanfei, age=17)