三种定时任务方式分别为

 org.springframework.scheduling.annotation.Scheduled
java.util.concurrent.ScheduledExecutorService
java.util.Timer

示例如下:

1.   新建Maven项目  schedule

2.   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
http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion>
<groupId>com.java</groupId>
<artifactId>schedule</artifactId>
<version>1.0.0</version> <parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.5.RELEASE</version>
</parent> <dependencies> <!-- Spring Boot -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency> <!-- 热部署 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>springloaded</artifactId>
<version>1.2.8.RELEASE</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>provided</scope>
</dependency> </dependencies> <build>
<finalName>${project.artifactId}</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.8</source>
<target>1.8</target>
<encoding>UTF-8</encoding>
</configuration>
</plugin> <plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>repackage</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>

3.   ScheduleStarter.java

package com.java;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.scheduling.annotation.EnableScheduling; @EnableScheduling
@SpringBootApplication
public class ScheduleStarter { public static void main(String[] args) {
SpringApplication.run(ScheduleStarter.class, args);
} }

4.   ScheduledDemo.java

package com.java.schedule;

import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component; @Component
public class ScheduledDemo { @Scheduled(cron = "0/5 * * * * *")
public void demoTask() {
System.out.println("[ ScheduledDemo ]\t\t" + System.currentTimeMillis());
} }

5.   ScheduledExecutorDemo.java

package com.java.schedule;

import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledThreadPoolExecutor;
import java.util.concurrent.TimeUnit; import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy; import org.springframework.stereotype.Component; @Component
public class ScheduledExecutorDemo { private ScheduledExecutorService executor = new ScheduledThreadPoolExecutor(5); @PostConstruct
public void demoTask() {
executor.scheduleAtFixedRate(new Runnable() { @Override
public void run() {
System.out.println("[ ScheduledExecutorDemo ]\t" + System.currentTimeMillis());
}
}, 0, 5, TimeUnit.SECONDS); } @PreDestroy
public void destory() {
executor.shutdown();
} }

6.   TimerDemo.java

package com.java.schedule;

import java.util.Timer;
import java.util.TimerTask; import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy; import org.springframework.stereotype.Component; @Component
public class TimerDemo { private Timer timer = new Timer(true); @PostConstruct
public void demoTask() {
timer.scheduleAtFixedRate(new TimerTask() { @Override
public void run() {
System.out.println("[ TimerDemo ]\t\t\t" + System.currentTimeMillis());
}
}, 0, 5000); } @PreDestroy
public void destory() {
timer.cancel();
} }

7.   运行ScheduleStarter.java,启动测试

控制台每隔5秒打印如下信息

[ ScheduledDemo ]        1548156125005
[ TimerDemo ] 1548156127556
[ ScheduledExecutorDemo ] 1548156127566

三种定时任务都正常运行!

.

05-11 15:15