Springboot 通过Schedule实现定时任务动态读取执行（从数据库读取）

前言：1、利用反射机制实现。

2、通过实现SchedulingConfigurer来配置定时任务。

3、此种方式只能实现项目启动时，定时任务执行，不能再项目启动后开启、暂停任务。

效果：

数据库中配置了2个任务（状态都是开启的，如果不想执行某条任务，可以将状态改为1）

表结构：

CREATE TABLE `schedule_setting` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`job_name` varchar(255) DEFAULT NULL,
`class_name` varchar(255) DEFAULT NULL,
`method` varchar(255) DEFAULT NULL,
`cron` varchar(255) DEFAULT NULL,
`status` int(2) DEFAULT NULL COMMENT '0 代表开启，1代表关闭',
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;

项目启动后开启执行，数据库中定义的2个方法

代码实现：

任务实体

/**
* @author : 徐长城
* @des：
* @date : 2019/8/20 21:37
*/
public class ScheduleConfig {
private Long id;
private String jobName;
private String className;
private String method;
private String cron;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getJobName() {
return jobName;
}
public void setJobName(String jobName) {
this.jobName = jobName;
}
public String getClassName() {
return className;
}
public void setClassName(String className) {
this.className = className;
}
public String getMethod() {
return method;
}
public void setMethod(String method) {
this.method = method;
}
public String getCron() {
return cron;
}
public void setCron(String cron) {
this.cron = cron;
}
}

Dao以及xml

Springboot获取bean

/**
* @author : 徐长城
* @des：获取bean
* @date : 2019/8/20 21:59
*/
@Component
public class ApplicationContextHelper implements ApplicationContextAware {
private static ApplicationContext applicationContext;
public ApplicationContextHelper() {
}
@Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
ApplicationContextHelper.applicationContext = applicationContext;
}
public static Object getBean(String beanName) {
return applicationContext != null?applicationContext.getBean(beanName):null;
}
}

定时配置

/**
* @author : 徐长城
* @des：
* @date : 2019/8/20 21:43
*/
@Component
public class ScheduleSetting implements SchedulingConfigurer {
@Autowired
private ScheduleDao scheduleDao;
@Override
public void configureTasks(ScheduledTaskRegistrar scheduledTaskRegistrar) {
// 获取所有任务
List<ScheduleConfig> scheduleList = scheduleDao.getScheduleList();
System.out.println(scheduleList.size());
for (ScheduleConfig s : scheduleList){
scheduledTaskRegistrar.addTriggerTask(getRunnable(s), getTrigger(s));
}
}
/**
* 转换首字母小写
*
* @param str
* @return
*/
public static String lowerFirstCapse(String str) {
char[] chars = str.toCharArray();
chars[0] += 32;
return String.valueOf(chars);
}
/**
* runnable
* @param scheduleConfig
* @return
*/
private Runnable getRunnable(ScheduleConfig scheduleConfig){
return new Runnable() {
@Override
public void run() {
Class<?> clazz;
try {
clazz = Class.forName(scheduleConfig.getClassName());
String className = lowerFirstCapse(clazz.getSimpleName());
Object bean = (Object) ApplicationContextHelper.getBean(className);
Method method = ReflectionUtils.findMethod(bean.getClass(), scheduleConfig.getMethod());
ReflectionUtils.invokeMethod(method, bean);
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
};
}
/**
* Trigger
* @param scheduleConfig
* @return
*/
private Trigger getTrigger(ScheduleConfig scheduleConfig){
return new Trigger() {
@Override
public Date nextExecutionTime(TriggerContext triggerContext) {
CronTrigger trigger = new CronTrigger(scheduleConfig.getCron());
Date nextExec = trigger.nextExecutionTime(triggerContext);
return nextExec;
}
};
}
}