Java：SpringBoot整合Spring Batch示例

文档

• https://docs.spring.io/spring-batch/docs/4.3.9/reference/html/index.html

基础概念

• JobLauncher：作业启动器，启动作业的入口。对应的实现类为SimpleJobLauncher。
• Job：作业，用于配置作业的相关配置，一个作业可以配置多个步骤，步骤之间是有序的。
• Step：步骤，作业具体执行的业务逻辑，一个Job可以配置多个Step。步骤有两种实现方式：
  • Tasklet方式：所有作业逻辑写在一个方法中。
  • Chunk方式：将一个完整的作业逻辑根据作用拆分到三个方法中
    • ItemReader：负责从数据源中读数据（如从文件、数据库等）。
    • ItemProcessor ：负责对读出来的数据进行非法校验和对数据进行加工。
    • ItemWriter：将数据写到某个目标中（如文件、数据库等）。
• JobBuilderFactory：作业构建起工厂，用于构建作业Job对象。
  • get(String name)：设置作业名称。
  • start(Step step)：设置作业启动的第一个步骤。
  • build()：构建Job对象。
• StepBuilderFactory：作业构建器工厂，用于构造步骤Step对象。
  • get(String name)：设置步骤名称。
  • tasklet(Tasklet tasklet)：设置Tasklet。
  • build()：构建Step对象。
• JobRepository：作业持久化，在执行作业的过程中用于操作spring batch相关的表，记录作业的相关状态等。

Tasklet方式示例

运行环境

$ java -version
java version "1.8.0_361"
Java(TM) SE Runtime Environment (build 1.8.0_361-b09)
Java HotSpot(TM) 64-Bit Server VM (build 25.361-b09, mixed mode)

spring-batch依赖

<dependency>
    <groupId>org.springframework.bootgroupId>
    <artifactId>spring-boot-starter-batchartifactId>
dependency>

<dependency>
    <groupId>org.springframework.batchgroupId>
    <artifactId>spring-batch-testartifactId>
    <scope>testscope>
dependency>


<dependency>
    <groupId>com.h2databasegroupId>
    <artifactId>h2artifactId>
    <scope>runtimescope>
dependency>

备注：第一次照着网上的文章写代码运行，直接报错，原因是缺少引入的依赖；需要引入数据库驱动，如H2或mysql

项目结构

$ tree 
.
├── pom.xml
└── src
    └── main
        ├── java
        │   └── com
        │       └── example
        │           └── demo
        │               ├── HelloWorldApplication.java
        │               ├── config
        │               │   └── BatchConfig.java
        │               └── task
        │                   └── HelloWorldTasklet.java
        └── resources

完整依赖pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0modelVersion>
    <parent>
        <groupId>org.springframework.bootgroupId>
        <artifactId>spring-boot-starter-parentartifactId>
        <version>2.7.7version>
        <relativePath/> 
    parent>

    <groupId>com.examplegroupId>
    <artifactId>demoartifactId>
    <version>0.0.1-SNAPSHOTversion>
    <name>demoname>
    <description>Demo project for Spring Bootdescription>

    <properties>
        <java.version>1.8java.version>
        <mybatis-plus.version>3.5.2mybatis-plus.version>
    properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>

        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-devtoolsartifactId>
            <scope>runtimescope>
            <optional>trueoptional>
        dependency>

        <dependency>
            <groupId>org.projectlombokgroupId>
            <artifactId>lombokartifactId>
            <optional>trueoptional>
        dependency>

        
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-batchartifactId>
        dependency>

        <dependency>
            <groupId>org.springframework.batchgroupId>
            <artifactId>spring-batch-testartifactId>
            <scope>testscope>
        dependency>

        <dependency>
            <groupId>com.h2databasegroupId>
            <artifactId>h2artifactId>
            <scope>runtimescope>
        dependency>

        
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-testartifactId>
            <scope>testscope>
        dependency>

        <dependency>
            <groupId>junitgroupId>
            <artifactId>junitartifactId>
            <scope>testscope>
        dependency>
    dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.bootgroupId>
                <artifactId>spring-boot-maven-pluginartifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombokgroupId>
                            <artifactId>lombokartifactId>
                        exclude>
                    excludes>
                configuration>
            plugin>
        plugins>
    build>

project>

编写业务逻辑

package com.example.demo.task;

import org.springframework.batch.core.StepContribution;
import org.springframework.batch.core.scope.context.ChunkContext;
import org.springframework.batch.core.step.tasklet.Tasklet;
import org.springframework.batch.repeat.RepeatStatus;
import org.springframework.stereotype.Component;

/**
 * 任务
 */
@Component
public class HelloWorldTasklet implements Tasklet {
    @Override
    public RepeatStatus execute(StepContribution contribution, ChunkContext chunkContext) throws Exception {
        System.out.println("Hello, World!");
        return RepeatStatus.FINISHED;
    }
}

配置作业步骤

package com.example.demo.config;

import com.example.demo.task.HelloWorldTasklet;
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.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * Spring Batch配置
 */
@Configuration
public class BatchConfig {
    @Autowired
    private JobBuilderFactory jobBuilderFactory;

    @Autowired
    private StepBuilderFactory stepBuilderFactory;

    @Autowired
    private HelloWorldTasklet helloWorldTasklet;

    @Bean
    public Step step() {
        return this.stepBuilderFactory.get("step")
                .tasklet(helloWorldTasklet)
                .build();
    }

    @Bean
    public Job job(Step step) {
        return this.jobBuilderFactory.get("job")
                .start(step)
                .build();
    }
}

启动类增加注解：@EnableBatchProcessing

package com.example.demo;

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

@EnableBatchProcessing
@SpringBootApplication
public class HelloWorldApplication {
    public static void main(String[] args) {
        SpringApplication.run(HelloWorldApplication.class, args);
    }

}

Chunk方式示例

项目结构

$ tree
.
├── pom.xml
└── src
    └── main
        ├── java
        │   └── com
        │       └── example
        │           └── demo
        │               ├── Application.java
        │               ├── config
        │               │   └── BatchConfig.java
        │               ├── dto
        │               │   └── Person.java
        │               └── processor
        │                   └── PersonItemProcessor.java
        └── resources
            └── persons.csv

依赖pom.xml 同上

package com.example.demo.dto;

import lombok.Data;

@Data
public class Person {
    private String name;
    private Integer age;
}

package com.example.demo.config;

import com.example.demo.dto.Person;
import com.example.demo.processor.PersonItemProcessor;
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.file.FlatFileItemReader;
import org.springframework.batch.item.file.builder.FlatFileItemReaderBuilder;
import org.springframework.batch.item.json.JacksonJsonObjectMarshaller;
import org.springframework.batch.item.json.JsonFileItemWriter;
import org.springframework.batch.item.json.builder.JsonFileItemWriterBuilder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.FileSystemResource;

/**
 * Spring Batch配置
 */
@Configuration
public class BatchConfig {
    @Autowired
    private JobBuilderFactory jobBuilderFactory;

    @Autowired
    private StepBuilderFactory stepBuilderFactory;


    @Bean
    public Step step() {
        return this.stepBuilderFactory.get("step")
                .<Person, Person>chunk(10)
                .reader(reader())
                .processor(processor())
                .writer(writer())
                .build();
    }

    @Bean
    public Job job(Step step) {
        return this.jobBuilderFactory.get("job")
                .start(step)
                .build();
    }

    /**
     * 读取csv文件
     * @return
     */
    @Bean
    public FlatFileItemReader<Person> reader() {
        return new FlatFileItemReaderBuilder<Person>()
                .name("personItemReader")
                .resource(new ClassPathResource("persons.csv"))
                .delimited()
                .names(new String[] {"name", "age"})
                .targetType(Person.class)
                .build();
    }

    /**
     * 处理器
     * @return
     */
    @Bean
    public PersonItemProcessor processor() {
        return new PersonItemProcessor();
    }

    /**
     * 写到json文件
     * @return
     */
    @Bean
    public JsonFileItemWriter<Person> writer() {
        return new JsonFileItemWriterBuilder<Person>()
                .jsonObjectMarshaller(new JacksonJsonObjectMarshaller<>())
                .resource(new FileSystemResource("persons.json"))
                .name("personItemWriter")
                .build();
    }

}

package com.example.demo.processor;

import com.example.demo.dto.Person;
import org.springframework.batch.item.ItemProcessor;

public class PersonItemProcessor implements ItemProcessor<Person, Person> {
    @Override
    public Person process(Person person) throws Exception {
        // 为每个对象年龄+1
        person.setAge(person.getAge() + 1);
        return person;
    }
}

启动入口

package com.example.demo;

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

@EnableBatchProcessing
@SpringBootApplication
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

}

启动SpringBoot即可运行任务

读取的persons.csv文件

Tom,18
Jack,20

生成的persons.json 文件

[
 {"name":"Tom","age":19},
 {"name":"Jack","age":21}
]

参考文章

1. SpringBatch从入门到实战(二)：HelloWorld
2. Spring Batch 之 Hello World
3. Spring Batch 入门级示例教程
4. Spring Batch 批处理框架优化实践，效率嘎嘎高！