詳細(xì)介紹SpringBoot如何實(shí)現(xiàn)集成ShedLock分布式定時(shí)任務(wù)

<dependency>
    <groupId>net.javacrumbs.shedlock</groupId>
    <artifactId>shedlock-spring</artifactId>
    <version>4.23.0</version>
</dependency>
 <!--每個(gè)外部存儲(chǔ)實(shí)例所需依賴包不一樣，這里是jdbc-->
<dependency>
    <groupId>net.javacrumbs.shedlock</groupId>
    <artifactId>shedlock-provider-jdbc-template</artifactId>
    <version>4.23.0</version>
</dependency>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <scope>runtime</scope>
</dependency>

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

server:
  port: 9999
spring:
  datasource:
    url: jdbc:mysql://192.168.31.158:3306/testjdbc?useUnicode=true&characterEncoding=UTF-8&serverTimezone=Asia/Shanghai
    username: root
    password: 123456
    driver-class-name: com.mysql.cj.jdbc.Driver
    type: com.mysql.cj.jdbc.MysqlDataSource

# MySQL, MariaDB
CREATE TABLE shedlock(name VARCHAR(64) NOT NULL, lock_until TIMESTAMP(3) NOT NULL,
    locked_at TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3), locked_by VARCHAR(255) NOT NULL, PRIMARY KEY (name));

# Postgres
CREATE TABLE shedlock(name VARCHAR(64) NOT NULL, lock_until TIMESTAMP NOT NULL,
    locked_at TIMESTAMP NOT NULL, locked_by VARCHAR(255) NOT NULL, PRIMARY KEY (name));

# Oracle
CREATE TABLE shedlock(name VARCHAR(64) NOT NULL, lock_until TIMESTAMP(3) NOT NULL,
    locked_at TIMESTAMP(3) NOT NULL, locked_by VARCHAR(255) NOT NULL, PRIMARY KEY (name));

# MS SQL
CREATE TABLE shedlock(name VARCHAR(64) NOT NULL, lock_until datetime2 NOT NULL,
    locked_at datetime2 NOT NULL, locked_by VARCHAR(255) NOT NULL, PRIMARY KEY (name));

# DB2
CREATE TABLE shedlock(name VARCHAR(64) NOT NULL PRIMARY KEY, lock_until TIMESTAMP NOT NULL,
    locked_at TIMESTAMP NOT NULL, locked_by VARCHAR(255) NOT NULL);

/**
 * @description: Shedlock集成Jdbc配置類
 * @author: DT
 * @date: 2021/5/22 0:07
 * @version: v1.0
 */
// 標(biāo)識(shí)該類為配置類
@Configuration
// //開(kāi)啟定時(shí)器
@EnableScheduling
// 開(kāi)啟定時(shí)任務(wù)鎖，指定一個(gè)默認(rèn)的鎖的時(shí)間30秒
@EnableSchedulerLock(defaultLockAtMostFor = "PT30S")
public class ShedlockJdbcConfig {

    /**
     * 配置鎖的提供者
     */
    @Bean
    public LockProvider lockProvider(DataSource dataSource) {
        return new JdbcTemplateLockProvider(
                JdbcTemplateLockProvider.Configuration.builder()
                        .withJdbcTemplate(new JdbcTemplate(dataSource))
                        .usingDbTime()
                        .build()
        );
    }
}

/**
 * @description: 開(kāi)啟分布式鎖定時(shí)任務(wù)
 * @author: DT
 * @date: 2021/5/22 0:23
 * @version: v1.0
 */
@Component
@CommonsLog
public class TimeTaskJob {

    private static Integer count = 1;

    // @SchedulerLock的作用是保證當(dāng)前定時(shí)任務(wù)的方法執(zhí)行時(shí)獲得鎖，忽略其他相同任務(wù)的執(zhí)行
    // name必須要指定，ShedLock就是根據(jù)這個(gè)name進(jìn)行相同任務(wù)判定的
    // name：定時(shí)任務(wù)的名字，就是數(shù)據(jù)庫(kù)中的主鍵(name)
    // lockAtMostFor：鎖的最大時(shí)間單位為毫秒
    // lockAtLeastFor：鎖的最小時(shí)間單位為毫秒

    /**
     * 任務(wù)1每5秒執(zhí)行一次
     * lockAtLeastFor：雖然,定時(shí)任務(wù)是每隔5秒執(zhí)行一次,但是,分布式鎖定義的是:每次任務(wù)要鎖住20秒，20秒是持有鎖的最小時(shí)間，必須等20秒后才釋放鎖，并且確保在20秒鐘內(nèi)，該任務(wù)不會(huì)運(yùn)行超過(guò)1次；
     * lockAtMostFor：鎖最大持有時(shí)間30秒，表示最多鎖定30秒鐘，主要用于防止執(zhí)行任務(wù)的節(jié)點(diǎn)掛掉（即使這個(gè)節(jié)點(diǎn)掛掉，在30秒鐘后，鎖也被釋放），一般將其設(shè)置為明顯大于任務(wù)的最大執(zhí)行時(shí)長(zhǎng)；如果任務(wù)運(yùn)行時(shí)間超過(guò)該值（即任務(wù)30秒鐘沒(méi)有執(zhí)行完），則該任務(wù)可能被重復(fù)執(zhí)行。
     */
    @Scheduled(cron = "0/5 * * * * ? ")
    @SchedulerLock(name = "testJob1",lockAtLeastFor = "20000", lockAtMostFor = "30000")
    public void scheduledTask1() {
        log.info(Thread.currentThread().getName() + "->>>任務(wù)1執(zhí)行第：" + (count++) + "次");
    }

    /**
     * 任務(wù)2每5秒執(zhí)行一次
     */
    @Scheduled(cron = "0/5 * * * * ? ")
    @SchedulerLock(name = "testJob2")
    public void scheduledTask2() {
        log.info(Thread.currentThread().getName() + "->>>任務(wù)2執(zhí)行第：" + (count++) + "次");
    }

}

@SpringBootApplication
public class JdbcApplication {

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

}