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java定时任务调度的实现方式

Timer

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这个相信大家都有用过,我也用过,但用的不多;

特点是:简单易用,但由于所有任务都是由同一个线程来调度,因此所有任务都是串行执行的,同一时间只能有一个任务在执行,前一个任务的延迟或异常都将会影响到之后的任务;能实现简单的定时任务,稍微复杂点(或要求高一些)的定时任务却不好实现。

ScheduledExecutor

这个我相信大家也都用过,而且用的比Timer多;正是鉴于Timer的缺陷,残爱死神复仇公主Java 5推出了基于线程池设计的ScheduledExecutor;

特点:每一个被调度的任务都会由线程池中一个线程去执行,因此任务是并发执行的,相互之间不会受到赵四章干扰。需要注意的是,只有当任务的执行时间到来时,ScheduedExecutor 才会真正启动一个线程,其余时间 ScheduledExecutor 都是在轮询任务的状态。

虽然用ScheduledExecutor和Calendar能够实现复杂任务调度,但实现起来还是比较麻烦,对开发还是不够友善。

Spring Scheduler

spring对任务调度的实现支持,可以指定任务的执行时间,但对任务队列和线程池的管控较弱;一般集成于项目中,小任务很方便。

JCronTab

JCronTab则是一款完全按照crontab语法编写的java任务调度工具。

特点:

可指定任务的执行时间;

提供完全按照Unix的UNIX-POSIX crontab的格式来规定时间;

支持多种任务调度的持久化方法,包括普通文件、数据库以及 XML 文件进行持久化;

JCronTab内置了发邮件功能,可以将任务执玥玥児行结果方便地发送给需要被通知的人;

设计和部署是高性能并可扩展。

Quartz

本文主角,请往下看

当然还有XXL-JOB、Elastic-Job、Saturn等等

quartz相关概念

Scheduler:调度器,进行任务调度;quartz的大脑

Job:业务job,亦可称业务组件;定时任务的具体执行业务需要实现此接口,调度器会调用此接口的execute方法完成我们的定时业务

JobDetail:用来定义业务Job的实例,我们可以称之为quartz job,很多时候我们谈到的job指的是JobDetail

Trigger:触发器,用来定义一个指定的Job何时被执行

JobBuilder:Job构建器,用来定义或创建JobDetail的实例;JobDetail限定了只能是Job的实例

TriggerBuilder:触发器构建器,用来定义或创建触发器的实例

具体为什么要分这么细,大家可以去查阅下相关资料,你会发现很多东西

工程实现

pom.xml



xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
4.0.0
com.lee
spring-boot-quartz
1.0-SNAPSHOT

1.8
1.8
1.8
1.1.10
1.2.5
1.1.10


org.springframework.boot
spring-boot-starter-parent
2.0.3.RELEASE



org.springframework.boot
spring-boot-starter-web


org.springframework.boot
spring-boot-starter-thymeleaf


org.springframewo桦甸青年rk.boot
spring-boot-starter-quartz


com.alibaba
druid-spring-boot-starter
${druid.version}


mysql
mysql-connector-java


com.github.pagehelper
pagehelper-spring-boot-starter
${pagehelper.version}



org.springframework.boot
spring-boot-starter-logging


*
*


test


ch.qos.logback
张乐泉logback-classic


org.projectlombok
lombok
true



spring-boot-quartz



org.springframework.boot
spring-boot-maven-plugin




application.xml

server:
port: 9001
servlet:
context-path: /quartz
spring:
thymeleaf:
mode: HTML
cache: false
#连接池配置
datasour老婆的脚ce:
type: com.alibaba.druid.pool.DruidDataSource
druid:
driver-class-name: com.mysq养甲虫赚钱中文版l.jdbc.Driver
url: jdbc:mysql://localhost:3306/spring-boot-quartz?useSSL=false&useUnicode=true
username: root
password: 123456
initial-size: 1 #连接池初始大小
max-active: 20 #连接池中最大的活跃连接数
min-idle: 1 #连接池中最小的活跃连接数
max-wait: 60000 #配置获取连接等待超时的时间
pool-prepared-statements: true #打开PS逍遥小神医金富贵Cache,并且指定每个连接上PSCache的大小
max-pool-prepared-statement-per-connection-size: 20
validation-query: SELECT 1 FROM DUAL
validation-query-timeout: 30000
test-on-borrow: false #是否在获得连接后检测其可用性
test-on-return: false #是否在连接放回连接池后检测其可用性
test-while-idle: true #是否在连接空闲一段时间后检测其可用性
quartz:
#相关属性配置
properties:
org:
quartz:
scheduler:
instanceName: quartzScheduler
instanceId: AUTO
jobStore:
class: org.quartz.impl.jdbcjobstore.JobStoreTX
driverDelegateClass: org.quartz.im鑫存管的钱能拿出来么pl.jdbcjobstore.StdJDBCDelegate
tablePrefix: QRTZ_
isClustered: false
clusterCheckinInterval: 10000
useProperties: false
threadPool:
class: org.quartz.simpl.SimpleThreadPool
threadCount: 10
threadPriority: 5
threadsInheritContextClassLoaderOfInitializingThread: true
#数据库方式
job-store-type: JDBC
#初始化表结构
jdbc:
initialize-schema: NEVER
#mybatis配置
mybatis:
type-aliases-package: com.l佐佐明木希ee.quartz.entity
mapper-locations: classpath:mybatis/mapper/*.xml
#分页配置, pageHelper是物理分页插件
pagehelper:
#4.0.0以后版本可以不设置该参数,该示例中是5.1.4
helper-dialect: mysql
#启用合理化,如果pageNum<1会查询第一页,如果pageNum>pages会查询最后一页
reasonable: true
logging:
level:
com.lee.quartz.mapper: debug

这样,quartz就配置好了,应用里面直接用即可

JobController.java

package com.lee.quartz.web;
import com.github.pagehelper.PageInfo;
import com.lee.quartz.common.Result;
import com.lee.quartz.entity.QuartzJob;
import com.lee.quartz.service.IJobService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation青鸟加速器.RestController;
@RestController
@RequestMapping("/job")
public class JobContr唐郁梦oller {
private final static Logger LOGGER = LoggerFactory.getLogger(JobController.class);
@Autowired
private IJobService jobService;

@SuppressWarnings({ "unchecked", "rawtypes" })
@PostMapping("义勇军帝师/add")
public Result save(QuartzJob quartz){
LOGGER.info("新增任务");
Result result = jobService.saveJob(quartz);
return result;
}
@PostMapping("/list")
public PageInfo list(String jobName,Integer pageNo,Integer pageSize){
LOGGER.info("任务列表");
PageInfo pageInfo = jobService.listQuartzJob(jobName, pageNo, pageSize);
return pageInfo;
}
@PostMapping("/trigger")
public Result trigger(String jobName, String jobGroup) {
LOGGER.info("触发任务");
Result result = jobService.triggerJob(jobName, jobGroup);
return result;
}
@PostMapping("/pause")
public Result pause(String jobName, String jobGroup) {
LOGGER.info("停止任务");
Result result = jobService.pauseJob(jobName, jobGroup);
return result;
}
@PostMapping("/resume")
public Result resume(String jobName, String jobGroup) {
LOGGER.info("恢复任务");
Result result = jobService.resumeJob(jobName, jobGroup);
return result;
}
@PostMapping("/remove")
public Result remove(String jobName, String jobGroup) {
LOGGER.info("移除任务");
Result result = jobService.removeJob(jobName, jobGroup);
return result;
}
}

JobServiceImpl.java

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package com.lee.quartz.service.impl;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.lee.quartz.common.Result;
import com.lee.quartz.entity.QuartzJob;
import com.lee.quartz.mapper.JobMapper;
import com.lee.quartz.service.IJobService;
import org.quartz.*;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class JobServiceImpl implements IJobServ瘦老头ice {
@Autowired
private Scheduler scheduler;
@Autowired
private JobMapper jobMapper;
@Override
public PageInfo listQuartzJob(String jobName, Integer pageNum, Integer pageSize) {
PageHelper.startPage(pageNum, pageSize);
List jobList = jobMapper.listJob(jobName);
PageInfo pageInfo = new PageInfo(jobList);
return pageInfo;
}
@Override
public Result saveJob(QuartzJob quartz){
try {
//如果是修改 展示旧的 任务
if(quartz.getOldJobGroup() != null && !"".equals(quartz.getOldJobGroup())){
JobKey key = new JobKey(quartz.getOldJobName(),quartz.getOldJobGroup());
scheduler.deleteJob(key);
}
//构建job信息
Class cls = Class.forName(quartz.getJobClassName()) ;
cls.newInstance();
JobDetail job = JobBuilder.newJob(cls).withIdentity(quartz.getJobName(),
quartz.getJobGroup())
.withDescription(quartz.getDescription()).build();
// 触发时间点
CronScheduleBuilder cronScheduleBuilder = CronScheduleBuilder.cronSchedule(quartz.getCronExpression().trim());
Trigger trigger = TriggerBuilder.newTrigger().withIdentity("trigger"+quartz.getJobName(), quartz.getJobGroup())
.startNow().withSchedule(cronScheduleBuilder).build();
//交由Scheduler安排触发
scheduler.scheduleJob(job, trigger);
} catch (Exception e) {
e.printStackTrace();
return Result.error();
}
return Result.ok();
}
@Override
public Result triggerJob(String jobName, String jobGroup) {
JobKey key = new JobKey(jobName,jobGroup);
try {
scheduler.triggerJob(key);
} catch (SchedulerException e) {
e.printStackTrace();
return Result.error();
}
return Result.ok();
}
@Override
public Result pauseJob(String jobName, String jobGroup) {
JobKey key = new JobKey(jobName,jobGroup);
try {
scheduler.pauseJob(key);
} catch (SchedulerException e) {
e.printStackTrace();
return Result.error();
}
return Result.ok();
}
@Override
public Result resumeJob(String jobName, String jobGroup) {
JobKey key = new JobKey(jobName,jobGroup);
try {
scheduler.resumeJob(key);
} catch (SchedulerException e) {
e.printStackTrace();
return Result.error();
}
return Result.ok();
}
@Override
public Result removeJob(String jobName, String jobGroup) {
try {
TriggerKey triggerKey = TriggerKey.triggerKey(jobName, jobGroup);
// 停止触发器
scheduler.pauseTrigger(triggerKey);
// 移除触发器
scheduler.unscheduleJob(triggerKey);
// 删除任务
scheduler.deleteJob(JobKey.jobKey(jobName, jobGroup));
System.out.println("removeJob:"+JobKey.jobKey(jobName));
} catch (Exception e) {
e.printStackTrace();
return Result.error();
}
return Result.ok();
}
}

主要就是以上文件,详情请查看spring-boot-quartz

工程里面数据源用的druid,springboot默认也会将该数据源应用到quartz,如果想给quartz单独配置数据源,可配合@QuartzDataSource来实现(更多quarz数据源问题,请查看spring-boot-2.0.3之quartz集成,数据源问题,源码探究)

最终效果如下


trigger状态

org.quartz.impl.jdbcjobstore.Constants中存放了一些列的常量,源代码如下

/* 
* All content copyright Terracotta, Inc., unless otherwise indicated. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy
* of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* Lice南通通州天气nse for the specific language governing permissions and limitations
* under the License.
*
*/
package org.quartz.impl.jdbcjobstore;
/**
*


* This interface can be implemented by any {@link
* org.quartz.impl.jdbcjobstore.DriverDelegate}

* class that needs to use the constants contained herein.
*


*
* @author Jeffrey Wescott
* @author James House
*/
public interface Constants {
/*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* Constants.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
// Table names
String TABLE_JOB_DETAILS = "JOB_DETAILS";
String TABLE_TRIGGERS = "TRIGGERS";
String TABLE_SIMPLE_TRIGGERS = "SIMPLE_TRIGGERS";
String TABLE_CRON_TRIGGERS = "CRON_TRIGGERS";
String TABLE_BLOB_TRIGGERS = "BLOB_TRIGGERS";
String TABLE_FIRED_TRIGGERS = "FIRED_TRIGGERS";
String TABLE_CALENDARS = "CALENDARS";
String TABLE_PAUSED_TRIGGERS = "PAUSED_TRIGGER_GRPS";
String TABLE_LOCKS = "LOCKS";
String TABLE_SCHEDULER_STATE = "SCHEDULER_STATE";
// TABLE_JOB_DETAILS columns names

String COL_SCHEDULER_NAME = "SCHED_NAME";

String COL_JOB_NAME = "JOB_NAME";
String COL_JOB_GROUP = "JOB_GROUP";
String COL_IS_DURABLE = "IS_DURABLE";
String COL_IS_VOLATILE = "IS_VOLATILE";
String COL_IS_NONCONCURRENT = "IS_NONCONCURRENT";
String COL_IS_UPDATE_DATA = "IS_UPDATE_DATA";
String COL_REQUESTS_RECOVERY = "REQUESTS_RECOVERY";
String COL_JOB_DATAMAP = "JOB_DATA";
String COL_JOB_CLASS = "JOB_CLASS_NAME";
String COL_DESCRIPTION = "DESCRIPTION";
// TABLE_TRIGGERS columns names
String COL_TRIGGER_NAME = "TRIGGER_NAME";
曹臻一String COL_TRIGGER_GROUP = "TRIGGER_GROUP";
String COL_NEXT_FIRE_TIME = "NEXT_FIRE_TIME";
String COL_PREV_FIRE_TIME = "PREV_FIRE_TIME";
String COL_TRIGGER_STATE = "TRIGGER_STATE";
String COL_TRIGGER_TYPE = "TRIGGER_TYPE";
String COL_START_TIME = "START_TIME";
String COL_END_TIME = "END_TIME";
String COL_PRIORITY = "PRIORITY";
String COL_MISFIRE_INSTRUCTION = "MISFIRE_INSTR";
String ALIAS_COL_NEXT_FIRE_TIME = "ALIAS_NXT_FR_TM";
// TABLE_SIMPLE_TRIGGERS columns names
String COL_REPEAT_COUNT = "REPEAT_COUNT";
String COL_REPEAT_INTERVAL = "REPEAT_INTERVAL";
String COL_TIMES_TRIGGERED = "TIMES_TRIGGERED";
// TABLE_CRON_TRIGGERS columns names
String COL_CRON_EXPRESSION = "CRON_EXPRESS布冯,娜扎,牟怎么读ION";
// TABLE_BLOB_TRIGGERS恋女童 columns names
String COL_BLOB = "BLOB_DATA";
String COL_TIME_ZONE_ID = "TIME_ZONE_ID";
// TABLE_FIRED_TRIGGERS columns names
String COL_INSTANCE_NAME = "INSTANCE_NAME";
String COL_F鲍喜静IRED_TIME = "FIRED_TIME";
String COL_SCHED_TIME = "SCHED_TIME";

String COL_ENTRY_ID = "ENTRY_ID";
String COL_ENTRY_STATE = "STATE";
// TABLE_CALENDARS columns names
String COL_CALENDAR_NAME = "CALENDAR_NAME";
String COL_CALENDAR = "CALENDAR";
// TABLE_LOCKS columns names
String COL_LOCK_NAME = "LOCK_NAME";
// TABLE_LOCKS columns names
String COL_LAST_CHECKIN_TIME = "LAST_CHECKIN_TIME";
String COL_CHECKIN_INTERVAL = "CHECKIN_INTERVAL";
// MISC CONSTANTS
String DEFAULT_TABLE_PREFIX = "QRTZ_";
// STATES
String STATE_WAITING = "WAITING";
String STATE_ACQUIRED = "ACQUIRED";
String STATE_EXECUTING = "EXECUTING";
String STATE_COMPLETE = "COMPLETE";
String STATE_BLOCKED = "BLOCKED";
String STATE_ERROR = "ERROR";
String STATE_PAUSED = "PAUSED";
String STATE_PAUSED_BLOCKED = "PAUSED_BLOCKED";
String STATE_DELETED = "DELETED";
/**
* @美女啪啪啪动态图片deprecated Whether a trigger has misfired is no longer a state, but
* rather now identified dynamically by whether the trigger's next fire
* time is more than the misfire threshold time in the past.
*/
String STATE_MISFIRED = "MISFIRED";
String ALL_GROUPS_PAUSED = "_$_ALL_GROUPS_PAUSED_$_";
// TRIGGER TYPES
/** Simple Trigger type. */
String TTYPE_SIMPLE = "SIMPLE";
/** Cron Trigger type. */
String TTYPE_CRON = "CRON";
/** Calendar Interval Trigger type. */
String TTYPE_CAL_INT = "CAL_INT";
/** Daily Time Interval Trigger type. */
String TTYPE_DAILY_TIME_INT = "DAILY_I";
/** A general blob Trigger type. */
String TTYPE_BLOB = "BLOB";
}
// EOF

里面有quartz的表名、各个表包含的列名、trigger状态、trigger类型等内容

状态包括

WAITING:等待中

ACQUIRED:将触发,此时还未到trigger真正的触发时刻

EXECUTING:触发,亦可理解成执行中,trigger真正的触发时刻

COMPLETE:完成,不再触发

BLOCKED:受阻,不允许并发执行job时会出现(@DisallowConcurrentExecution)

ERROR:出错

PAUSED:暂停中

PAUSED_BLOCKED:暂停受阻,不允许并发执行job时会出现(@DisallowConcurrentExecution)

DELETED:已删除

MISFIRED:触发失败,已弃用,有另外的替代方式

状态变化流程图如下所示


trigger的初始状态是WAITING,处于WAITING状态的trigger等待被触发。调度线程会不停地扫triggers表,根据NEXT_FIRE_TIME提前拉取即将触发的trigger,如果这个trigger被该调度线程拉取到,它的状态就会变为ACQUIRED。因为是提前拉取trigger,并未到达trigger真正的触发时刻,所以调度线程会等到真正触发的时刻,再将trigger状态由ACQUIRED改为EXECUTING。如果这个trigger不再执行,就将状态改为COMPLETE,否则为WAITING,开始新的周期。如果这个周期中的任何环节抛出异常,trigger的状态会变成ERROR。如果手动暂停这个trigger,状态会变成PAUSED。

总结

Quartz作为一个开源的作业调度框架,提供了巨大的灵活性而不牺牲简单性。我们能够用它来为执行一个作业而创建简单的或复杂的调度。它有很多特征,如:数据库、集群、插件、JavaMail支持,EJB作业预构建,支持cron-like表达式等等;

springboot集成quartz非常简单,最简单的情况下只需要引入依赖我们就可以享受quartz提供的功能,springboot默认会帮我们配置好quartz;当然我们也可以自定义配置来实现quartz的定制。

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