目录
- 文档
- 基础概念
- Tasklet方式示例
- Chunk方式示例
- 参考文章
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
<!-- spring-batch -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-batch</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.batch</groupId>
<artifactId>spring-batch-test</artifactId>
<scope>test</scope>
</dependency>
<!-- h2、mysql... -->
<dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
<scope>runtime</scope>
</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
<?xml version="1.0" encoding="UTF-8"?>
<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>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.7.7</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>demo</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
<mybatis-plus.version>3.5.2</mybatis-plus.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<!-- spring-batch -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-batch</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.batch</groupId>
<artifactId>spring-batch-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
<scope>runtime</scope>
</dependency>
<!-- test -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<excludes>
<exclude>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</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
- SpringBatch从入门到实战(二):HelloWorld
- Spring Batch 之 Hello World
- Spring Batch 入门级示例教程
- Spring Batch 批处理框架优化实践,效率嘎嘎高!