01 Quartz-初识Quartz-样例入手

2019-05-20 本文已影响0人花神子

quartz

Quartz是OpenSymphony开源组织在Job scheduling领域又一个开源项目，它可以与J2EE与J2SE应用程序相结合也可以单独使用。Quartz可以用来创建简单或为运行十个，百个，甚至是好几万个Jobs这样复杂的程序。Jobs可以做成标准的Java组件或 EJBs。Quartz的最新版本为Quartz 2.3.0。

1、quartz简介

Quartz是一个完全由java编写的开源作业调度框架。使用非常简单。简单地创建一个实现org.quartz.Job接口的java类。Job接口包含唯一的方法：

public void execute(JobExecutionContext context) throws JobExecutionException;

Job接口实现类里面，添加一些逻辑到execute()方法。一旦你配置好Job实现类并设定好调度时间表，Quartz将密切注意剩余时间。当调度程序确定该是通知你的作业的时候，Quartz框架将调用你Job实现类（作业类）上的execute()方法并允许做它该做的事情。

2 入门实例

不管是使用什么SpringBoot还是其他框架我们都需要做一件事情就是需要添加pom依赖

<dependencies>
     <dependency>
        <groupId>org.quartz-scheduler</groupId>
        <artifactId>quartz</artifactId>
        <version>2.3.0</version>
     </dependency> 
</dependencies>

第一步编写我们需要处理的任务逻辑

样例中其实只是简单的做了一行日志输出(输出线程名以及job信息)，代替业务逻辑。

package com.maozw.quartz.job;

import org.quartz.*;

/**
 *
 *
 * @description
 * @see
 * @author maozhengwei
 * @data 2019-05-16 13:10
 * @version V1.0.0
 **/
public class MyJob implements Job {
    /**
     * <p>
     * Called by the <code>{@link Scheduler}</code> when a <code>{@link Trigger}</code>
     * fires that is associated with the <code>Job</code>.
     * </p>
     *
     * <p>
     * The implementation may wish to set a
     * {@link JobExecutionContext#setResult(Object) result} object on the
     * {@link JobExecutionContext} before this method exits.  The result itself
     * is meaningless to Quartz, but may be informative to
     * <code>{@link JobListener}s</code> or
     * <code>{@link TriggerListener}s</code> that are watching the job's
     * execution.
     * </p>
     *
     * @param context
     * @throws JobExecutionException if there is an exception while executing the job.
     */
    public void execute(JobExecutionContext context) throws JobExecutionException {
        String name = context.getJobDetail().getKey().getName();
        String group = context.getJobDetail().getKey().getGroup();
        System.out.println(Thread.currentThread().getName() + " > > > > MyJob.execute " + "name :" +name+ " group :" + group);
    }
}

第二步获取调度Scheduler实例，进行初始化

样例中我简单做了下封装，仅此而已：

package com.maozw.quartz.scheduler;

import org.quartz.*;
import org.quartz.impl.StdSchedulerFactory;
import java.util.Date;

/**
 * 
 * 
 * @description 
 * @see 
 * @author maozhengwei
 * @data 2019-05-16 14:15
 * @version V1.0.0
 **/
public class QuartzScheduler {

    /**
     * 定义 全局 Scheduler 方便以下方法使用
     */
    private static Scheduler scheduler;

    /**Scheduler
     * 初始化
     */
    static {
        try {
            scheduler = getSechduler();
        } catch (SchedulerException e) {
            e.printStackTrace();
        }
    }

    /**
     * 获取Scheduler instance 
     * 实际生产中不建议这么做：最好采用资源隔离的方式；避免任务过多进行资源抢占导致任务misfire
     * @return
     * @throws SchedulerException
     */
    public static Scheduler getSechduler() throws SchedulerException {
        SchedulerFactory schedulerFactory = new StdSchedulerFactory();
        if (scheduler == null) {
            synchronized (QuartzScheduler.class) {
                if (scheduler == null) {
                    scheduler = schedulerFactory.getScheduler();
                }
            }
        }
        return scheduler;
    }

    /**
     * add Job 
     * 这里可以作为通用型，可以定制job以及不同Job不同的启动参数，采用适配器模式去适配不同的触发器
     * @param jobGroup
     * @param jobName
     * @param jobClass
     * @throws SchedulerException
     */
    public void addJob(String jobGroup, String jobName, Class jobClass) throws SchedulerException {
        JobDetail jobDetail = JobBuilder.newJob(jobClass).withIdentity(jobName, jobGroup).build();

        // 创建触发器
        // withIntervalInSeconds(2)表示每隔2s执行任务
        Date triggerDate = new Date();
        SimpleScheduleBuilder schedBuilder = SimpleScheduleBuilder
                .simpleSchedule()
                .withIntervalInSeconds(2)
                .repeatForever();
        TriggerBuilder<Trigger> triggerBuilder  = TriggerBuilder
                .newTrigger()
                .withIdentity(jobName, jobGroup);
        Trigger trigger = triggerBuilder
                .startAt(triggerDate)
                .withSchedule(schedBuilder)
                .build();
        // 将job trigger放入scheduler
        scheduler.scheduleJob(jobDetail, trigger);
    }

    /**
     * start scheduler
     * @throws SchedulerException
     */
    public void start() throws SchedulerException {
        if (scheduler.isStarted()){
            return;
        }
        scheduler.start();
    }
}

第三步启动

样例中使用main方法：

/**
 * @description
 * @see
 * @author maozhengwei
 * @data 2019-05-16 13:08
 * @version V1.0.0
 **/
public class QuartzApplication {

    public static void main(String[] args) throws SchedulerException {
        QuartzScheduler quartzScheduler = new QuartzScheduler();
        quartzScheduler.addJob("g1","n1", MyJob.class);
        quartzScheduler.addJob("g2","n2", MyJob.class);
        quartzScheduler.start();
    }    
}

第五步输出结果

其实我们从输出结果也能看到一些东西：

不是每次都是同一个线程在执行任务；
结果来看默认的线程池大小是10

DefaultQuartzScheduler_Worker-1 > > > > MyJob.execute name :n1 group :g1
DefaultQuartzScheduler_Worker-2 > > > > MyJob.execute name :n2 group :g2
DefaultQuartzScheduler_Worker-3 > > > > MyJob.execute name :n1 group :g1
DefaultQuartzScheduler_Worker-4 > > > > MyJob.execute name :n2 group :g2
DefaultQuartzScheduler_Worker-5 > > > > MyJob.execute name :n1 group :g1
DefaultQuartzScheduler_Worker-6 > > > > MyJob.execute name :n2 group :g2
DefaultQuartzScheduler_Worker-7 > > > > MyJob.execute name :n1 group :g1
DefaultQuartzScheduler_Worker-8 > > > > MyJob.execute name :n2 group :g2
DefaultQuartzScheduler_Worker-9 > > > > MyJob.execute name :n1 group :g1
DefaultQuartzScheduler_Worker-10 > > > > MyJob.execute name :n2 group :g2
DefaultQuartzScheduler_Worker-1 > > > > MyJob.execute name :n1 group :g1
DefaultQuartzScheduler_Worker-2 > > > > MyJob.execute name :n2 group :g2
DefaultQuartzScheduler_Worker-3 > > > > MyJob.execute name :n1 group :g1
DefaultQuartzScheduler_Worker-4 > > > > MyJob.execute name :n2 group :g2

为了证明这个猜测我们看一下：这俩先不做源码分析：只是简单的看看：quartz 默认帮我们做了哪些工作；我们在quartz 的源码包里找到如下文件：quartz.properties

# Default Properties file for use by StdSchedulerFactory
# to create a Quartz Scheduler Instance, if a different
# properties file is not explicitly specified.
org.quartz.scheduler.instanceName: DefaultQuartzScheduler
org.quartz.scheduler.rmi.export: false
org.quartz.scheduler.rmi.proxy: false
org.quartz.scheduler.wrapJobExecutionInUserTransaction: false

org.quartz.threadPool.class: org.quartz.simpl.SimpleThreadPool
org.quartz.threadPool.threadCount: 10
org.quartz.threadPool.threadPriority: 5
org.quartz.threadPool.threadsInheritContextClassLoaderOfInitializingThread: true

org.quartz.jobStore.misfireThreshold: 60000

org.quartz.jobStore.class: org.quartz.simpl.RAMJobStore

我们可以看到

org.quartz.threadPool.threadCount: 10
org.quartz.threadPool.class: org.quartz.simpl.SimpleThreadPool

这也应征了我们猜测。

OK ！

01 Quartz-初识Quartz-样例入手

1、quartz简介

2 入门实例

第一步编写我们需要处理的任务逻辑

第二步获取调度Scheduler实例，进行初始化

第三步启动

第五步输出结果

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热点阅读

01 Quartz-初识Quartz-样例入手

1、quartz简介

2 入门实例

第一步 编写我们需要处理的任务逻辑

第二步 获取调度Scheduler实例，进行初始化

第三步 启动

第五步 输出结果

猜你喜欢

热点阅读

第一步编写我们需要处理的任务逻辑

第二步获取调度Scheduler实例，进行初始化

第三步启动

第五步输出结果