SpringBoot & SpringTask

Spring 自带定时任务 @Scheduled 
在线Cron表达式   https://cron.qqe2.com/
1.@Scheduled参数运用
2.单线程测试
3.多线程测试
4.@Scheduled(cron = "${demo.cron}") 占位符格式测试
5.源码分析

导入依赖

<?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>

    <groupId>com.demo</groupId>
    <artifactId>SpringTaskDemo</artifactId>
    <version>1.0-SNAPSHOT</version>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.1.RELEASE</version>

        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <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.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.20</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-quartz</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>jul-to-slf4j</artifactId>
            <version>1.7.36</version>
        </dependency>
    </dependencies>

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

</project>

多线程配置类

/**
 * @author WenZiR
 * @projectName SpringTaskDemo
 * @description: TODO
 * @date 2022-04-02 23:04
 */
@Configuration
@EnableAsync
public class SpringTaskConfig {
    /**
     * 核心线程池大小
     */
    @Value("${com.springTask.corePoolSize}")
    private int corePoolSize;

    /**
     * 线程池最大书面
     */
    @Value("${com.springTask.maxPoolSize}")
    private int maxPoolSize;

    /**
     * 等待队列大小
     */
    @Value("${com.springTask.queueCapacity}")
    private int queueCapacity;

    @Bean
    public Executor taskExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(corePoolSize);
        executor.setMaxPoolSize(maxPoolSize);
        executor.setQueueCapacity(queueCapacity);
        executor.initialize();
        return executor;
    }
}

编写application.properties文件

#线程池设置参数
#线程池设置参数
com.springTask.corePoolSize=10
com.springTask.maxPoolSize=200
com.springTask.queueCapacity=10

demo.cron=0/1 * * * * *

测试类

@Component
@Slf4j
public class TestJob {


    /**
     * 每隔 10s 执行一次
     */
    @Scheduled(cron = "0/10 * * * * ?")
    public void task1() {
        log.info(Thread.currentThread ().getName ()+
                "【job1】开始执行：{}", LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
    }

    /**
     * 从启动时间开始，间隔 2s 执行
     * 固定间隔时间
     */
    @Scheduled(fixedRate = 2000)
    public void task2() {
        log.info(Thread.currentThread ().getName ()+
                "【job2】开始执行：{}",  LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
    }

    /**
     * 从启动时间开始，延迟 5s 后间隔 4s 执行
     * 固定等待时间
     */
    @Scheduled(fixedDelay = 4000, initialDelay = 5000)
    public void task3() {
        log.info(Thread.currentThread ().getName ()+
                "【job3】开始执行：{}",  LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
    }



    /**
     * 按照标准时间来算，每隔 1s 执行一次
     */
    @Async
    @Scheduled(cron = "0/1 * * * * * ")
    public  void taskAsync1()   {
        log.info (Thread.currentThread ().getName ()
                + "【job1】开始执行：{}",
                LocalDateTime.now ().format (DateTimeFormatter.ofPattern ("yyyy-MM-dd HH:mm:ss")));
   //        Thread.sleep (10000 *60);

    }


    /**
     * 按照标准时间来算，每隔 1s 执行一次
     */
    @Async
    @Scheduled(cron = "0/1 * * * * * ")
    public  void taskAsync2()   {
        log.info (Thread.currentThread ().getName ()+
                "【job2】开始执行：{}",
                LocalDateTime.now ().format (DateTimeFormatter.ofPattern ("yyyy-MM-dd HH:mm:ss")));
  
    }

    /**
     * 按照标准时间来算，每隔 1s 执行一次
     */
    @Async
    @Scheduled(cron = "0/1 * * * * * ")
    public  void taskAsync3()   {
        log.info (Thread.currentThread ().getName ()+
                        "【job3】开始执行：{}",
                LocalDateTime.now ().format (DateTimeFormatter.ofPattern ("yyyy-MM-dd HH:mm:ss")));

    }
}

启动类

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

测试

• @Scheduled注解基本使用
  
• 单线程测试
  
• 多线程测试
  
• 占位符测试
  

总结 & 源码分析

public @interface Scheduled {
	//cron  [秒] [分] [小时] [日] [月] [周] [年]
	String cron() default "";

	//默认是一个空字符串，即取服务器所在地的时区。比如我们一般使用的时区Asia/Shanghai。
	//该字段我们一般留空。
	String zone() default "";
	
	//默认未开启
	long fixedDelay() default -1;
	//上一次执行完毕时间点之后**秒再执行	  固定等待时间
	String fixedDelayString() default "";
	
    //默认未开启
	long fixedRate() default -1;
	//上一次开始执行时间点之后**秒再执行   固定间隔时间
	String fixedRateString() default "";

	//默认未开启
	long initialDelay() default -1;
	 //第一次延迟**秒后执行
	String initialDelayString() default "";

}

线程池里面有坑