添加包
<dependency>
<groupId>net.javacrumbs.shedlock</groupId><artifactId>shedlock-spring</artifactId><version>2.2.0</version></dependency><dependency><groupId>net.javacrumbs.shedlock</groupId><artifactId>shedlock-provider-jdbc-template</artifactId><version>2.2.0</version></dependency>添加表
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
@EnableScheduling
public 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.ponent;
@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
