初识Quartz（一）
首先需要一个任务：
package quartz_project;
import java.util.Date;
import org.quartz.Job;
import org.quartz.JobExecutionContext;
import org.quartz.JobExecutionException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* 一个简单的任务：打印Hello World
*
* @author caijw
*/
public class HelloJob implements Job {
private static Logger _log = LoggerFactory.getLogger(HelloJob.class);
@Override
public void execute(JobExecutionContext ctx) throws JobExecutionException {
//打印Hello World! - 当前日期
_log.info("Hello World! - " + new Date());
}
}
由上面代码可以看出，任务类要实现job接口，在execute方法中是任务的具体实现。
然后设定调度策略：
package quartz_project;
import java.util.Date;
import org.quartz.DateBuilder;
import org.quartz.JobBuilder;
import org.quartz.JobDetail;
import org.quartz.Scheduler;
import org.quartz.SchedulerFactory;
import org.quartz.Trigger;
import org.quartz.TriggerBuilder;
import org.quartz.impl.StdSchedulerFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* 该例子将：
* 1. 展示何如开始和结束quartz的调用器（scheduler），
* 2. 展示在quartz中，调度器是如何运行作业（job）的。
*
* @author caijw
*/
public class SimpleExample {
public void run() throws Exception {
Logger log = LoggerFactory.getLogger(SimpleExample.class);
log.info("----- Initializing --------");
//第一步我们必须获取一个调度器
SchedulerFactory sf = new StdSchedulerFactory();
Scheduler sched = sf.getScheduler();
log.info("----- Initialization complete -------");
//作业的执行时间（这里需要注意，下面详细说明）
Date runTime = DateBuilder.evenMinuteDate(new Date());
log.info("----- scheduling job --------");
//创建一项作业
JobDetail job = JobBuilder.newJob(HelloJob.class)
.withIdentity("job1", "group1")
.build();
//创建一个触发器
Trigger trigger = TriggerBuilder.newTrigger()
.withIdentity("trigger1", "group1")
.startAt(runTime).build(); //该触发器将在runTime时执行作业
//告诉调度器使用该触发器来安排作业
sched.scheduleJob(job, trigger);
log.info(job.getKey() + " will run at: " + runTime);
sched.start();//启动调度器
log.info("------ started scheduler -------");
log.info("------ waiting 65 seconds ------");
try {
Thread.sleep(65L * 1000L);
} catch (Exception e) {
log.error(e.getMessage(), e);
}
log.info("------- shutting down ------");
sched.shutdown();//关闭调度器
log.info("------- shutdown complete -------");
}
}
注意：
1. Date runTime = DateBuilder.evenMinuteDate(new Date()); //当前时间的下一分钟
假如JVM在执行到这一句时，时间为17：23：22，那么runTime就是17：24：00
DateBuilder类似的方法：
2. 并不是把Job的实例注册到Scheduler中，而是JobDetail的实例。
3. Scheduler 实例被关闭之后你就不能调用它的 start() 方法了。这是因为 shutdown() 方法销毁了为 Scheduler 创建的所有的资源(线程，数据库连接等)。假如你在 shutdown() 之后调用 start()你将收到 SchedulerException 的异常。
4. Job 的实例要到该执行它们的时候才会实例化出来。每次 Job 被执行，一个新的 Job 实例会被创建（延迟加载的思想）。所以Job 不必担心线程安全性，因为同一时刻仅有一个线程去执行给定 Job 类的实例，甚至是并发执行同一 Job 也是如此。
Maven的配置文件：
<project xmlns="http://maven.apache.org/POM/4.0.0" 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"> <modelVersion>4.0.0</modelVersion> <groupId>quartz_project</groupId> <artifactId>quartz_project</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>quartz_project</name> <url>http://maven.apache.org</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> </properties> <dependencies> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>1.6.1</version> </dependency> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>1.2.16</version> </dependency> <dependency> <groupId>org.quartz-scheduler</groupId> <artifactId>quartz</artifactId> <version>2.1.1</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.10</version> <scope>test</scope> </dependency> </dependencies> </project>
单元测试类：
package quartz_project;
import org.junit.Test;
/**
* 单元测试
*
* @author caijw
*/
public class SimpleExampleTest {
@Test
public void testRun() throws Exception {
SimpleExample example = new SimpleExample();
example.run();
}
}
执行结果分析：
------------------------------------------------------- T E S T S ------------------------------------------------------- Running quartz_project.SimpleExampleTest [INFO] 25 一月 07:26:16.359 下午 main [quartz_project.SimpleExample] ----- Initializing -------- [INFO] 25 一月 07:26:16.437 下午 main [org.quartz.impl.StdSchedulerFactory] Using default implementation for ThreadExecutor [INFO] 25 一月 07:26:16.437 下午 main [org.quartz.simpl.SimpleThreadPool] Job execution threads will use class loader of thread: main [INFO] 25 一月 07:26:16.468 下午 main [org.quartz.core.SchedulerSignalerImpl] Initialized Scheduler Signaller of type: class org.quartz.core.SchedulerSignalerImpl [INFO] 25 一月 07:26:16.468 下午 main [org.quartz.core.QuartzScheduler] Quartz Scheduler v.2.1.1 created. [INFO] 25 一月 07:26:16.468 下午 main [org.quartz.simpl.RAMJobStore] RAMJobStore initialized. [INFO] 25 一月 07:26:16.468 下午 main [org.quartz.core.QuartzScheduler] Scheduler meta-data: Quartz Scheduler (v2.1.1) 'DefaultQuartzScheduler' with instanceId 'NON_CLUSTERED' Scheduler class: 'org.quartz.core.QuartzScheduler' - running locally. NOT STARTED. Currently in standby mode. Number of jobs executed: 0 Using thread pool 'org.quartz.simpl.SimpleThreadPool' - with 10 threads. Using job-store 'org.quartz.simpl.RAMJobStore' - which does not support persistence. and is not clustered. [INFO] 25 一月 07:26:16.468 下午 main [org.quartz.impl.StdSchedulerFactory] Quartz scheduler 'DefaultQuartzScheduler' initialized from default resource file in Quartz package: 'quartz.properties' [INFO] 25 一月 07:26:16.468 下午 main [org.quartz.impl.StdSchedulerFactory] Quartz scheduler version: 2.1.1 [INFO] 25 一月 07:26:16.468 下午 main [quartz_project.SimpleExample] ----- Initialization complete ------- [INFO] 25 一月 07:26:16.484 下午 main [quartz_project.SimpleExample] ----- scheduling job -------- [INFO] 25 一月 07:26:16.500 下午 main [quartz_project.SimpleExample] group1.job1 will run at: Sat Jan 25 19:27:00 CST 2014 [INFO] 25 一月 07:26:16.500 下午 main [org.quartz.core.QuartzScheduler] Scheduler DefaultQuartzScheduler_$_NON_CLUSTERED started. [INFO] 25 一月 07:26:16.500 下午 main [quartz_project.SimpleExample] ------ started scheduler ------- [INFO] 25 一月 07:26:16.500 下午 main [quartz_project.SimpleExample] ------ waiting 65 seconds ------ [INFO] 25 一月 07:26:19.703 下午 Timer-0 [org.quartz.utils.UpdateChecker] New Quartz update(s) found: 2.1.7 [http://www.terracotta.org/kit/reflector?kitID=default&pageID=QuartzChangeLog] [INFO] 25 一月 07:27:00.031 下午 DefaultQuartzScheduler_Worker-1 [quartz_project.HelloJob] Hello World! - Sat Jan 25 19:27:00 CST 2014 [INFO] 25 一月 07:27:21.500 下午 main [quartz_project.SimpleExample] ------- shutting down ------ [INFO] 25 一月 07:27:21.500 下午 main [org.quartz.core.QuartzScheduler] Scheduler DefaultQuartzScheduler_$_NON_CLUSTERED shutting down. [INFO] 25 一月 07:27:21.500 下午 main [org.quartz.core.QuartzScheduler] Scheduler DefaultQuartzScheduler_$_NON_CLUSTERED paused. [INFO] 25 一月 07:27:21.500 下午 main [org.quartz.core.QuartzScheduler] Scheduler DefaultQuartzScheduler_$_NON_CLUSTERED shutdown complete. [INFO] 25 一月 07:27:21.500 下午 main [quartz_project.SimpleExample] ------- shutdown complete ------- Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 65.39 sec Results : Tests run: 1, Failures: 0, Errors: 0, Skipped: 0