CREATE TABLE `shedlock` (
`name` varchar(64) COLLATE utf8mb4_unicode_ci NOT NULL,
`lock_until` timestamp(3) NULL DEFAULT NULL,
`locked_at` timestamp(3) NULL DEFAULT NULL,
`locked_by` varchar(255) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
PRIMARY KEY (`name`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

添加config

import net.javacrumbs.shedlock.core.LockProvider;import net.javacrumbs.shedlock.provider.jdbctemplate.JdbcTemplateLockProvider;import net.javacrumbs.shedlock.spring.ScheduledLockConfiguration;import net.javacrumbs.shedlock.spring.ScheduledLockConfigurationBuilder;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import org.springframework.scheduling.annotation.EnableScheduling;

import javax.sql.DataSource;import java.time.Duration;

@Configuration@EnableSchedulingpublic class ShedlockConfig {

    @Bean    public LockProvider lockProvider(DataSource dataSource) {        return new JdbcTemplateLockProvider(dataSource);    }

    @Bean    public ScheduledLockConfiguration scheduledLockConfiguration(LockProvider lockProvider) {        return ScheduledLockConfigurationBuilder                .withLockProvider(lockProvider)                .withPoolSize(10)                .withDefaultLockAtMostFor(Duration.ofMinutes(10))                .build();    }}具体的定时任务

import net.javacrumbs.shedlock.core.SchedulerLock;import net.javacrumbs.shedlock.spring.annotation.EnableSchedulerLock;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.context.annotation.Configuration;import org.springframework.scheduling.annotation.EnableScheduling;import org.springframework.scheduling.annotation.Scheduled;import org.springframework.stereotype.Component;

@Component@Configuration@EnableScheduling@EnableSchedulerLock(defaultLockAtMostFor = "PT30S") //重点地方public class MarkRefreshScheduler {

    private final static Logger logger = LoggerFactory.getLogger(MarkRefreshScheduler.class);

    //每周一早上5点执行一次，用户的热度值和hot标识归零    @Scheduled(cron = "0 0/2 * * * ? ")    @SchedulerLock(name = "headNumCronName", lockAtMostFor = 5 * 1000, lockAtLeastFor = 5 * 1000)//重点地方    public void refreshHotSumAndIsOnTop() {        logger.info("begin refreshHotSumAndIsOnTop...");        //do something        logger.info("begin refreshHotSumAndIsOnTop...");

    }}结果

通过修改数据库表中的数据实现锁

里面有四个字段

主键name：每个定时任务的一个名字

locked_at：锁的开始时间

lock_until：锁的结束时间

再定时开始时，会更新这两个时间，在时间之内的定时是不会被执行的