SpringBoot 定时任务

前言

SpringBoot默认已经帮我们实行了，只需要添加相应的注解就可以实现。

SpringBoot整合定时任务其实就两点：
1.创建一个能被定时任务类，方法上加入@Scheduled注解
2.在启动类application上加入@EnableScheduling注解

1、pom文件

只需要引入 Spring Boot Starter 包即可

<?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 http://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>2.1.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <groupId>com.huzh</groupId>
    <artifactId>springboot-scheduled</artifactId>
    <version>0.0.1-SNAPSHOT</version>

    <name>springboot-scheduled</name>
    <description>springboot-scheduled</description>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

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

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

        <!-- 调试热启动 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

2、application类启用定时

在启动类上面加上@EnableScheduling即可开启定时

@SpringBootApplication
@EnableScheduling
public class SpringbootScheduledApplication {

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

3、创建定时任务类TestTimer

1.@Component注解表明一个类会作为组件类，并告知Spring要为这个类创建bean。
2.@EnableScheduling开启定时

@Component
public class TestTimer {

    @Scheduled(cron = "0/1 * * * * ?")
    private void test() {
        System.out.println("执行定时任务的时间是" + new Date());
    }
}

备注：

需要注意的是@Scheduled(cron = “0/1 * * * * ?”)中cron的值根据自己实际需要去写，可参考http://cron.qqe2.com/