(E) How to dynamically modify the execution time of the next timer

springboot using SchedulingConfigurer can set the timer next execution time.

As for the dynamic modification of runtime, then there are the most commonly used in three ways: 1, Interface 2, 3 database, configuration center hot update

We are here to get hold of the interface examples.

package com.example.demo.javaConfig;

import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.Trigger;
import org.springframework.scheduling.TriggerContext;
import org.springframework.scheduling.annotation.SchedulingConfigurer;
import org.springframework.scheduling.config.ScheduledTaskRegistrar;
import org.springframework.scheduling.support.CronTrigger;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.text.SimpleDateFormat;
import java.util.Date;

@RestController
@Configuration
public class ScheduleDynamicTest implements SchedulingConfigurer {

    private String cron = "0 0/1 * * * ?";

    @RequestMapping("changeCron")
    public String changeCron(){
        cron = "0 0/3 * * * ?";
        return "ok" ;
    }

    @Override
    public void configureTasks(ScheduledTaskRegistrar scheduledTaskRegistrar) {

        // 构建一个线程来执行job
        Runnable job = new Runnable() {
            @Override 
            public  void RUN () { 
                the SimpleDateFormat SDF = new new the SimpleDateFormat ( "the MM-dd-YYYY HH: mm: SS" ); 
                String nowStr = sdf.format ( new new a Date ()); 
                System.out.println (nowStr); 
            } 
        }; 

        // build a trigger, and set the next execution time rewriting trigger 
        the Trigger trigger = new new the Trigger () { 

            @Override 
            public a Date nextExecutionTime (triggerContext triggerContext) { 
                a CronTrigger CT = new new a CronTrigger (the cron);
                 return ct.nextExecutionTime(triggerContext);
            }
        };

        scheduledTaskRegistrar.addTriggerTask(job,trigger);

    }
}