本次使用redis作为数据库，存储定时任务类
redis的连接不是重点，重点是解析序列化处理过的任务数组和Quartz如何添加任务

1. JobEntity 用来保存执行任务类

public class JobEntity implements Serializable {
    //cron表达式
    private String cronExpression;
    //组名
    private String jobGroup = Scheduler.DEFAULT_GROUP;
    
    private String jobName;

    private String className; // 执行任务的类(完整路径  包含包名)

    private String methodName;//执行任务的方法名

    set ...
    get ...
}

2.任务类

public class Test {
    public void xun(){
        System.out.println("--------定时任务2-------");
    }
}
public class Test2 {
    public void test(){
        System.out.println("--------定时任务1-------");
    }
}

3.存入redis

public void start2() {
        Gson gson = new Gson();
        JobEntity jobEntity = new JobEntity();
        jobEntity.setMethodName("test");
        jobEntity.setJobName("MyJob2");
        jobEntity.setClassName("zebra.shjf.schedule.Test2");
        jobEntity.setCronExpression("0/1 * * * * ?");
        jobEntity.setJobGroup("MyGroup2");

        JobEntity jobEntity2 = new JobEntity();
        jobEntity2.setMethodName("xun");
        jobEntity2.setJobName("MyJob");
        jobEntity2.setClassName("zebra.shjf.schedule.Test");
        jobEntity2.setCronExpression("0/1 * * * * ?");
        jobEntity2.setJobGroup("MyGroup");

        ArrayList<JobEntity> list = new ArrayList<JobEntity>();
        list.add(jobEntity);
        list.add(jobEntity2);
        jedis.set("jobEntity", gson.toJson(list));
    }
 127.0.0.1:6379> get "jobEntity"
    "[{\"cronExpression\":\"0/1 * * * * ?\",\"jobGroup\":\"MyGroup2\",\"jobName\":\"MyJob2\",\"className\":\"zebra.shjf.schedule.Test2\",\"methodName\":\"test\"},{\"cronExpression\":\"0/1 * * * * ?\",\"jobGroup\":\"MyGroup\",\"jobName\":\"MyJob\",\"className\":\"zebra.shjf.schedule.Test\",\"methodName\":\"xun\"}]"

3.重点解析(注释解释)

   @Test
    public void start3() throws Exception {
        //准备添加从redis中得到的实体类，目的是遍历，然后添加到定时容器中，去执行
        ArrayList<JobEntity>arrayList=new ArrayList<JobEntity>();

        Gson gson = new Gson();
        //从redis中得到json数组对象
        String str = jedis.get("jobEntity");
        //json解析器
        JsonParser parser = new JsonParser();
        //解析出json元素，jsonElement对象中有一些方法判断是对象还是数组，各对应不同的处理
        JsonElement jsonElement = parser.parse(str);

        //如果是json数组就转换为jsonArray
        JsonArray jsonArray = null;
        if (jsonElement.isJsonArray()) {
            jsonArray = jsonElement.getAsJsonArray();
        }
        //遍历
        Iterator it= jsonArray.iterator();
        while (it.hasNext()){
            JsonElement e = (JsonElement)it.next();
            //把获得的数组中每一个对象，重新添加到数组中
            arrayList.add(gson.fromJson(e,JobEntity.class));
        }
        //容器
        Scheduler scheduler=null;
        //遍历数组
        for(JobEntity jobEntity:arrayList){
            //遍历获得每个job对象
            JobDetail jobDetail = JobBuilder.newJob(ScheduledTasks.class).withIdentity(jobEntity.getJobName(), jobEntity.getJobGroup()).//
                    usingJobData("className", jobEntity.getClassName())
                    .usingJobData("methodName", jobEntity.getMethodName()).build();
            //jobDetail.getJobDataMap().put("test", jobEntity);
            //为每个任务动态构建表达式
            CronScheduleBuilder cron = CronScheduleBuilder.cronSchedule(jobEntity.getCronExpression());
            //构建触发器
            CronTrigger trigger = TriggerBuilder.newTrigger().withIdentity(jobEntity.getJobName(), jobEntity.getJobGroup()).withSchedule(cron).build();

            SchedulerFactory schedulerFactory = new StdSchedulerFactory();
            scheduler = schedulerFactory.getScheduler();
            scheduler.scheduleJob(jobDetail, trigger);
        }
        scheduler.start();

        Thread thread = new Thread();
        thread.sleep(10000);

    }