【Quartz】深入Job、JobDetail、JobDataMap、Trigger
阿新 • • 發佈：2018-12-10
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<p></p><p> <a href="http://my.csdn.net/Evankaka" rel="nofollow" target="_blank">林炳文Evankaka</a>原創作品。轉載請註明出處<a href="http://blog.csdn.net/evankaka" rel="nofollow" target="_blank">http://blog.csdn.net/evankaka</a><span style="font-size:18px;"></span></p><p style="color:#444444;"><span style="font-size:18px;">Quartz API核心介面有：</span></p><ul style="color:#444444;"><li><span style="font-size:18px;">Scheduler – 與scheduler互動的主要API；</span></li><li><span style="font-size:18px;">Job – 你通過scheduler執行任務，你的任務類需要實現的介面；</span></li><li><span style="font-size:18px;">JobDetail – 定義Job的例項；</span></li><li><span style="font-size:18px;">Trigger – 觸發Job的執行；</span></li><li><span style="font-size:18px;">JobBuilder – 定義和建立JobDetail例項的介面;</span></li><li><span style="font-size:18px;">TriggerBuilder – 定義和建立Trigger例項的介面；</span></li><li><span style="font-size:18px;"><br></span></li></ul><p><span style="font-size:24px;"><a href="http://download.csdn.net/detail/evankaka/8704469" rel="nofollow" target="_blank">本文工程免費下載</a></span></p><h1><a name="t0"></a><span style="font-size:18px;color:#FF0000;"><span style="font-size:24px;">一、Job</span></span></h1><p></p><p><span style="font-size:18px;"> 在上一節中，Job中定義了實際的業務邏輯，而JobDetail包含Job相關的配置資訊。<strong><span style="color:#FF0000;">在Quartz中，每次Scheduler執行Job時，在呼叫其execute()方法之前，它需要先根據JobDetail提供的Job型別建立一個Job class的例項，在任務執行完以後，Job class的例項會被丟棄，Jvm的垃圾回收器會將它們回收。</span></strong>因此編寫Job的具體實現時，需要注意：</span></p><p><span style="font-size:18px;">(1) 它必須具有一個無引數的建構函式；</span></p><p><span style="font-size:18px;">(2) 它不應該有靜態資料型別，因為每次Job執行完以後便被回收，因此在多次執行時靜態資料沒法被維護。</span></p><p><span style="font-size:18px;"> 在JobDetail中有這麼一個成員JobDataMap，JobDataMap是Java Map介面的具體實現，並添加了一些便利的方法用於儲存與讀取原生型別資料，裡面包含了當Job例項執行時，你希望提供給它的所有資料物件。</span></p><p><span style="font-size:18px;"> 可以藉助JobDataMap為Job例項提供屬性/配置，可以通過它來追蹤Job的執行狀態等等。對於第一種情況，可以在建立Job時，新增JobDataMap資料，在Job的execute()中獲取資料，第二種，則可以在Listener中通過獲取JobDataMap中儲存的狀態資料追蹤Job的執行狀態。</span></p><p><span style="font-size:18px;">一個實現了Job介面的Java類就能夠被排程器執行。介面如下：</span></p><p></p><pre onclick="hljs.copyCode(event)"><code class="language-java hljs"><ol class="hljs-ln"><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="1"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">packageorg.quartz;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="2"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="3"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">publicinterface Job {</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="4"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="5"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">execute</span><span class="hljs-params">(JobExecutionContext context)</span> throwsJobExecutionException</span>;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="6"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="7"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">}</div></div></li></ol></code><div class="hljs-button" data-title="複製"></div></pre><br><span style="font-size:18px;"> 很簡的，當Job的trigger觸發時，Job的execute(..)方法就會被排程器呼叫。被傳遞到這個方法裡來的JobExecutionContext物件提供了帶有job執行時的資訊：執行它的排程器控制代碼、觸發它的觸發器控制代碼、job的JobDetail物件和一些其他的項。JobDetail物件是Job在被加到排程器裡時所建立的，它包含有很多的Job屬性設定，和JobDataMap一樣，可以用來儲存job例項時的一些狀態資訊。</span><p></p><span style="font-size:18px;">比如如下任務類</span><br><p></p><pre onclick="hljs.copyCode(event)"><code class="language-java hljs"></code><div class="hljs-button" data-title="複製"></div></pre><div class="dp-highlighter bg_java"><div class="bar"><div class="tools"><b>[java]</b> <a href="#" class="ViewSource" title="view plain" onclick="dp.sh.Toolbar.Command('ViewSource',this);return false;">view plain</a><span data-mod="popu_168"> <a href="#" class="CopyToClipboard" title="copy" onclick="dp.sh.Toolbar.Command('CopyToClipboard',this);return false;">copy</a><div style="position: absolute; left: 612px; top: 1543px; width: 16px; height: 16px; z-index: 99;"><embed id="ZeroClipboardMovie_1" src="https://csdnimg.cn/public/highlighter/ZeroClipboard.swf" loop="false" menu="false" quality="best" bgcolor="#ffffff" width="16" height="16" name="ZeroClipboardMovie_1" align="middle" allowscriptaccess="always" allowfullscreen="false" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer" flashvars="id=1&width=16&height=16" wmode="transparent"></div><div style="position: absolute; left: 612px; top: 1543px; width: 16px; height: 16px; z-index: 99;"><embed id="ZeroClipboardMovie_2" src="https://csdnimg.cn/public/highlighter/ZeroClipboard.swf" loop="false" menu="false" quality="best" bgcolor="#ffffff" width="16" height="16" name="ZeroClipboardMovie_2" align="middle" allowscriptaccess="always" allowfullscreen="false" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer" flashvars="id=2&width=16&height=16" wmode="transparent"></div></span><span data-mod="popu_169"> <a href="#" class="PrintSource" title="print" onclick="dp.sh.Toolbar.Command('PrintSource',this);return false;">print</a></span><a href="#" class="About" title="?" onclick="dp.sh.Toolbar.Command('About',this);return false;">?</a></div></div><ol start="1" class="dp-j"><li class="alt"><span><span><code </span><span class="keyword">class</span><span>=</span><span class="string">"language-java"</span><span>></span><span class="keyword">package</span><span> com.mucfc; </span></span></li><li class=""><span> </span></li><li class="alt"><span><span class="keyword">import</span><span> java.util.Date; </span></span></li><li class=""><span> </span></li><li class="alt"><span><span class="keyword">import</span><span> org.apache.commons.logging.Log; </span></span></li><li class=""><span><span class="keyword">import</span><span> org.apache.commons.logging.LogFactory; </span></span></li><li class="alt"><span><span class="keyword">import</span><span> org.quartz.Job; </span></span></li><li class=""><span><span class="keyword">import</span><span> org.quartz.JobDetail; </span></span></li><li class="alt"><span><span class="keyword">import</span><span> org.quartz.JobExecutionContext; </span></span></li><li class=""><span><span class="keyword">import</span><span> org.quartz.JobExecutionException; </span></span></li><li class="alt"><span> </span></li><li class=""><span><span class="keyword">public</span><span> </span><span class="keyword">class</span><span> NewJob </span><span class="keyword">implements</span><span> Job{ </span></span></li><li class="alt"><span> <span class="keyword">static</span><span> Log logger = LogFactory.getLog(NewJob.</span><span class="keyword">class</span><span>); </span></span></li><li class=""><span> <span class="annotation">@Override</span><span> </span></span></li><li class="alt"><span> <span class="keyword">public</span><span> </span><span class="keyword">void</span><span> execute(JobExecutionContext context) </span><span class="keyword">throws</span><span> JobExecutionException { </span></span></li><li class=""><span> System.err.println(<span class="string">"Hello! NewJob is executing."</span><span>+</span><span class="keyword">new</span><span> Date() ); </span></span></li><li class="alt"><span> <span class="comment">//取得job詳情</span><span> </span></span></li><li class=""><span> JobDetail jobDetail = context.getJobDetail(); </span></li><li class="alt"><span> <span class="comment">// 取得job名稱</span><span> </span></span></li><li class=""><span> String jobName = jobDetail.getClass().getName(); </span></li><li class="alt"><span> logger.info(<span class="string">"Name: "</span><span> + jobDetail.getClass().getSimpleName()); </span></span></li><li class=""><span> <span class="comment">//取得job的類</span><span> </span></span></li><li class="alt"><span> logger.info(<span class="string">"Job Class: "</span><span> + jobDetail.getJobClass()); </span></span></li><li class=""><span> <span class="comment">//取得job開始時間</span><span> </span></span></li><li class="alt"><span> logger.info(jobName + <span class="string">" fired at "</span><span> + context.getFireTime()); </span></span></li><li class=""><span> logger.info(<span class="string">"Next fire time "</span><span> + context.getNextFireTime()); </span></span></li><li class="alt"><span> } </span></li><li class=""><span> </span></li><li class="alt"><span>} </span></li><li class=""><span></code> </span></li></ol></div><pre class="java" name="code" style="display: none;" onclick="hljs.copyCode(event)"><code class="language-java hljs"><ol class="hljs-ln" style="width:50px"><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="1"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">package</span> com.mucfc;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="2"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="3"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">import</span> java.util.Date;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="4"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="5"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">import</span> org.apache.commons.logging.Log;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="6"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">import</span> org.apache.commons.logging.LogFactory;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="7"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">import</span> org.quartz.Job;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="8"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">import</span> org.quartz.JobDetail;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="9"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">import</span> org.quartz.JobExecutionContext;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="10"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">import</span> org.quartz.JobExecutionException;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="11"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="12"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">public</span> <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">NewJob</span> <span class="hljs-keyword">implements</span> <span class="hljs-title">Job</span></span>{</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="13"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-keyword">static</span> Log logger = LogFactory.getLog(NewJob.class); </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="14"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-meta">@Override</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="15"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">execute</span><span class="hljs-params">(JobExecutionContext context)</span> <span class="hljs-keyword">throws</span> JobExecutionException </span>{</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="16"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> System.err.println(<span class="hljs-string">"Hello! NewJob is executing."</span>+<span class="hljs-keyword">new</span> Date() );</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="17"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-comment">//取得job詳情</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="18"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> JobDetail jobDetail = context.getJobDetail(); </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="19"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-comment">// 取得job名稱</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="20"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> String jobName = jobDetail.getClass().getName();</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="21"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> logger.info(<span class="hljs-string">"Name: "</span> + jobDetail.getClass().getSimpleName()); </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="22"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-comment">//取得job的類</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="23"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> logger.info(<span class="hljs-string">"Job Class: "</span> + jobDetail.getJobClass()); </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="24"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-comment">//取得job開始時間</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="25"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> logger.info(jobName + <span class="hljs-string">" fired at "</span> + context.getFireTime()); </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="26"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> logger.info(<span class="hljs-string">"Next fire time "</span> + context.getNextFireTime()); </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="27"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> }</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="28"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="29"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">}</div></div></li></ol></code><div class="hljs-button" data-title="複製"></div></pre><br><br><span style="font-size:18px;"> 當 Scheduler 呼叫一個 Job，一個 JobexecutionContext 傳遞給 execute() 方法。JobExecutionContext 物件讓 Job 能訪問 Quartz 執行時候環境和 Job 本身的明細資料。這就類似於在 Java Web 應用中的 servlet 訪問 ServletContext 那樣。通過 JobExecutionContext，Job 可訪問到所處環境的所有資訊，包括註冊到 Scheduler 上與該 Job 相關聯的 JobDetail 和 Triiger。</span><br><p></p><h1><a name="t1"></a><span style="font-size:18px;"><span style="font-size:24px;color:#FF0000;">二、JobDetail </span><br></span></h1><p><span style="font-size:18px;"></span></p><p><span style="font-size:18px;">JobDetail例項是通過JobBuilder類建立的</span></p><p><span style="font-size:18px;">可以通過匯入該類下的所有靜態方法</span></p><pre onclick="hljs.copyCode(event)"><code class="language-java hljs"> <span class="hljs-keyword">import</span> <span class="hljs-keyword">static</span> org.quartz.JobBuilder.*;</code><div class="hljs-button" data-title="複製"></div></pre><span style="font-size:18px;">然後是建立：</span><pre onclick="hljs.copyCode(event)"><code class="language-java hljs"><ol class="hljs-ln"><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="1"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> 建立一個JobDetail例項</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="2"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> JobDetail jobDetail = newJob(NewJob.class).withIdentity(<span class="hljs-string">"job1_1"</span>, <span class="hljs-string">"jGroup1"</span>).build();</div></div></li></ol></code><div class="hljs-button" data-title="複製"></div></pre><span style="font-size:18px;">如果不匯入靜態包：</span><p><span style="font-size:18px;">那麼就要用：</span></p><pre onclick="hljs.copyCode(event)"><code class="language-java hljs"><ol class="hljs-ln" style="width:867px"><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="1"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> 建立一個JobDetail例項</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="2"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> obDetail jobDetail = JobBuilder.newJob(NewJob.class).withIdentity(<span class="hljs-string">"job1_1"</span>, <span class="hljs-string">"jGroup1"</span>).build();</div></div></li></ol></code><div class="hljs-button" data-title="複製"></div></pre><br><p><span style="font-size:18px;">對於部署在 Scheduler 上的每一個 Job 只建立了一個 JobDetail 例項。JobDetail 是作為 Job 例項進行定義的。注意到在程式碼 中不是把 Job 物件註冊到 Scheduler；實際註冊的是一個 JobDetail 例項。</span><br></p><pre onclick="hljs.copyCode(event)"><code class="language-java hljs"><ol class="hljs-ln" style="width:882px"><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="1"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">startSchedule</span><span class="hljs-params">()</span> </span>{</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="2"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-keyword">try</span> { </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="3"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-comment">// 1、建立一個JobDetail例項，指定Quartz</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="4"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> JobDetail jobDetail = JobBuilder.newJob(NewJob.class) <span class="hljs-comment">// 任務執行類 </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="5"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> .withIdentity(<span class="hljs-string">"job1_1"</span>, <span class="hljs-string">"jGroup1"</span>)<span class="hljs-comment">// 任務名，任務組 </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="6"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> .build(); </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="7"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-comment">//2、建立Trigger</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="8"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> SimpleScheduleBuilder builder=SimpleScheduleBuilder.simpleSchedule()</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="9"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> .withIntervalInSeconds(<span class="hljs-number">5</span>) <span class="hljs-comment">//設定間隔執行時間 </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="10"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> .repeatSecondlyForTotalCount(<span class="hljs-number">5</span>);<span class="hljs-comment">//設定執行次數</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="11"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="12"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> Trigger trigger=TriggerBuilder.newTrigger().withIdentity(</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="13"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-string">"trigger1_1"</span>,<span class="hljs-string">"tGroup1"</span>).startNow().withSchedule(builder).build();</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="14"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-comment">//3、建立Scheduler</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="15"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> Scheduler scheduler=StdSchedulerFactory.getDefaultScheduler(); </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="16"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-comment">//4、排程執行</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="17"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> scheduler.scheduleJob(jobDetail, trigger); </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="18"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> scheduler.start(); </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="19"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> } <span class="hljs-keyword">catch</span> (SchedulerException e) {</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="20"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> e.printStackTrace();</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="21"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> }</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="22"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="23"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> }</div></div></li></ol></code><div class="hljs-button" data-title="複製"></div></pre><span style="font-size:18px;"><span style="background-color:rgb(255,255,255);">結果：</span></span><p></p><p align="center"><span style="font-size:18px;"><span style="background-color:rgb(255,255,255);"><img src="https://img-blog.csdn.net/20150429102136525" alt=""><br></span></span></p><p><span style="font-size:18px;"><span style="background-color:rgb(255,255,255);">從上面的程式碼中可以看JobDetail 被加到 Scheduler 中了，而不是 job。Job 類是作為 JobDetail 的一部份，但是它直到 Scheduler 準備要執行它的時候才會被例項化的。</span><br></span></p><p><span style="font-size:18px;"></span></p><table style="border-width:1px;border-style:none;" align="center" border="1"><tbody><tr><td><strong>直到執行時才會建立 Job 例項</strong> <br><br>Job 的例項要到該執行它們的時候才會例項化出來。每次 Job 被執行，一個新的 Job 例項會被建立。其中暗含的意思就是你的 Job 不必擔心執行緒安全性，因為同一時刻僅有一個執行緒去執行給定 Job 類的例項，甚至是併發執行同一 Job 也是如此。</td></tr></tbody></table><br><p></p><p><span style="font-size:18px;"> 可以看到，我們傳給scheduler一個JobDetail例項，因為我們在建立JobDetail時，將要執行的job的類名傳給了JobDetail，所以scheduler就知道了要執行何種型別的job；每次當scheduler執行job時，在呼叫其execute(…)方法之前會建立該類的一個新的例項；執行完畢，對該例項的引用就被丟棄了，例項會被垃圾回收；這種執行策略帶來的一個後果是，job必須有一個無參的建構函式（當使用預設的JobFactory時）；另一個後果是，在job類中，不應該定義有狀態的資料屬性，因為在job的多次執行中，這些屬性的值不會保留。</span></p><p><span style="font-size:18px;"> 那麼如何給job例項增加屬性或配置呢？如何在job的多次執行中，跟蹤job的狀態呢？答案就是:JobDataMap，JobDetail物件的一部分。</span></p><span style="font-size:18px;"></span><h3 id="jobdatamap" style="color:#444444;"></h3><h1><a name="t3"></a><span style="font-size:24px;color:#FF0000;">三、JobDataMap</span></h1><p><span style="font-size:18px;"> JobDataMap中可以包含不限量的（序列化的）資料物件，在job例項執行的時候，可以使用其中的資料；JobDataMap是Java Map介面的一個實現，額外增加了一些便於存取基本型別的資料的方法。</span></p><p><span style="font-size:18px;">將job加入到scheduler之前，在構建JobDetail時，可以將資料放入JobDataMap，如下示例：</span></p><span style="font-size:18px;"></span><p style="color:#444444;"></p><p><span style="font-size:18px;"></span></p><pre onclick="hljs.copyCode(event)"><code class="language-java hljs"><ol class="hljs-ln" style="width:952px"><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="1"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">package</span> com.mucfc;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="2"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">import</span> org.quartz.Job;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="3"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">import</span> org.quartz.JobDataMap;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="4"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">import</span> org.quartz.JobExecutionContext;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="5"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">import</span> org.quartz.JobExecutionException;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="6"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">import</span> org.quartz.JobKey;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="7"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">public</span> <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">NewJob2</span> <span class="hljs-keyword">implements</span> <span class="hljs-title">Job</span></span>{</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="8"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="9"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-meta">@Override</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="10"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">execute</span><span class="hljs-params">(JobExecutionContext context)</span> <span class="hljs-keyword">throws</span> JobExecutionException </span>{</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="11"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> JobKey key = context.getJobDetail().getKey();</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="12"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> JobDataMap dataMap = context.getJobDetail().getJobDataMap();</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="13"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> String jobSays = dataMap.getString(<span class="hljs-string">"jobSays"</span>);</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="14"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-keyword">float</span> myFloatValue = dataMap.getFloat(<span class="hljs-string">"myFloatValue"</span>);</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="15"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> System.out.println(<span class="hljs-string">"Instance "</span> + key + <span class="hljs-string">" of DumbJob says: "</span> + jobSays + <span class="hljs-string">", and val is: "</span> + myFloatValue);</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="16"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="17"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> }</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="18"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="19"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">}</div></div></li></ol></code><div class="hljs-button" data-title="複製"></div></pre><p></p><p><span style="font-size:18px;">在job的執行過程中，可以從JobDataMap中取出資料，如下示例：</span></p><p></p><pre onclick="hljs.copyCode(event)"><code class="language-java hljs"><ol class="hljs-ln" style="width:882px"><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="1"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">package</span> com.mucfc;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="2"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="3"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">import</span> org.quartz.JobBuilder;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="4"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">import</span> org.quartz.JobDetail;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="5"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">import</span> org.quartz.Scheduler;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="6"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">import</span> org.quartz.SchedulerException;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="7"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">import</span> org.quartz.SimpleScheduleBuilder;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="8"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">import</span> org.quartz.Trigger;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="9"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">import</span> org.quartz.TriggerBuilder;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="10"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">import</span> org.quartz.impl.StdSchedulerFactory;</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="11"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"><span class="hljs-keyword">public</span> <span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">Test</span> </span>{</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="12"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">startSchedule</span><span class="hljs-params">()</span> </span>{</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="13"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-keyword">try</span> {</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="14"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="15"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="16"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-comment">// 1、建立一個JobDetail例項，指定Quartz</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="17"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> JobDetail jobDetail = JobBuilder.newJob(NewJob.class) <span class="hljs-comment">// 任務執行類 </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="18"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> .withIdentity(<span class="hljs-string">"job1_1"</span>, <span class="hljs-string">"jGroup1"</span>)<span class="hljs-comment">// 任務名，任務組 </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="19"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> .build(); </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="20"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="21"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> JobDetail jobDetail2 = JobBuilder.newJob(NewJob2.class)</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="22"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> .withIdentity(<span class="hljs-string">"job1_2"</span>, <span class="hljs-string">"jGroup1"</span>) </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="23"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> .usingJobData(<span class="hljs-string">"jobSays"</span>, <span class="hljs-string">"Hello World!"</span>)</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="24"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> .usingJobData(<span class="hljs-string">"myFloatValue"</span>, <span class="hljs-number">3.141f</span>)</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="25"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> .build();</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="26"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="27"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="28"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="29"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-comment">//2、建立Trigger</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="30"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> SimpleScheduleBuilder builder=SimpleScheduleBuilder.simpleSchedule()</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="31"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> .withIntervalInSeconds(<span class="hljs-number">5</span>) <span class="hljs-comment">//設定間隔執行時間 </span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="32"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> .repeatSecondlyForTotalCount(<span class="hljs-number">5</span>);<span class="hljs-comment">//設定執行次數</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="33"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="34"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> Trigger trigger=TriggerBuilder.newTrigger().withIdentity(</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="35"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-string">"trigger1_1"</span>,<span class="hljs-string">"tGroup1"</span>).startNow().withSchedule(builder).build();</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="36"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-comment">//3、建立Scheduler</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="37"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> Scheduler scheduler=StdSchedulerFactory.getDefaultScheduler(); </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="38"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-comment">//4、排程執行</span></div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="39"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> scheduler.scheduleJob(jobDetail2, trigger); </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="40"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> scheduler.start(); </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="41"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> } <span class="hljs-keyword">catch</span> (SchedulerException e) {</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="42"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> e.printStackTrace();</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="43"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> }</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="44"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="45"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> }</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="46"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> <span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">static</span> <span class="hljs-keyword">void</span> <span class="hljs-title">main</span><span class="hljs-params">(String[] args)</span> </span>{</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="47"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="48"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> Test test=<span class="hljs-keyword">new</span> Test();</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="49"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> test.startSchedule();</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="50"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> }</div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="51"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line"> </div></div></li><li><div class="hljs-ln-numbers"><div class="hljs-ln-line hljs-ln-n" data-line-number="52"></div></div><div class="hljs-ln-code"><div class="hljs-ln-line">}</div></div></li></ol></code><div class="hljs-button" data-title="複製"></div></pre><br><span style="font-size:18px;">結果：</span><p></p><p align="center"><img src="https://img-blog.csdn.net/20150429102128477" alt=""><br></p><p><span style="font-size:18px;"><br></span></p><p><span style="font-size:24px;color:#FF0000;">四、 Trigger</span><span style="font-size:18px;"><br></span></p><p><span style="font-size:18px;"><em> </em> Trigger物件是用來觸發執行Job的。當排程一個job時，我們例項一個觸發器然後調整它的屬性來滿足job執行的條件。觸發器也有一個和它相關的JobDataMap，它是用來給被觸發器觸發的job傳引數的。Quartz有一些不同的觸發器型別，不過，用得最多的是SimpleTrigger和CronTrigger。</span></p><p><span style="font-size:18px;"> 如果我們需要在給定時刻執行一次job或者在給定時刻觸發job隨後間斷一定時間不停的執行的話，SimpleTrigger是個簡單的解決辦法；如果我們想基於類似日曆排程的觸發job的話，比如說，在每個星期五的中午或者在每個月第10天的10：15觸發job時，CronTrigger是很有用的。</span></p><p><span style="font-size:18px;"> 為什麼用jobs和triggers呢？很多工排程器並沒有任務和觸發器的概念，一些任務排程器簡單定義一個“job”為在一個執行時間伴隨一些小任務標示，其他的更像Quartz裡job和trigger物件的聯合體。在開發Quartz時，開發者們決定，在排程時間表和在這上面執行的工作應該分開。這是很有用的。</span></p><p><span style="font-size:18px;"> 例如，job能夠獨立於觸發器被建立和儲存在任務排程器裡，並且，很多的觸發器能夠與同一個job關聯起來。這個鬆耦合的另一個好處就是在與jobs關聯的觸發器終止後，我們能夠再次配置保留在排程器裡的jobs，這樣的話，我們能夠再次排程這些jobs而不需要重新定義他們。我們也可以在不重新定義一個關聯到job的觸發器的情況下，修改或替代