spring的Scheduled（定時任務）和多線程

一、前言

      在我們日常的開發中，經常用到數據同步的更新，這時我們采用的是spring的定時任務和java的多線程進行數據的更新，進行時實的服務調用。

二.實現思路

           1.創建線程類

           2.創建ExecutorService線程連接池

           3.調用線程池操作

           4.spring的Scheduled（定時任務）配置 

三.創建線程類

     創建的線程類，我們采用的是實現Runnable接口，使用該類可以共享，在線程中要么繼承Thread，或者實現Runnable接口，其中Thread是實現了Runnable的接口，實現Runnable接口可以更好的擴展和共享類，因為java是單繼承多實現的程序。

public class ArchiveTask implements Runnable {
     
    /**
     * log.
     */
    private static Logger logger = LoggerFactory.getLogger(ArchiveTask.class);
     
    //注：由於spring事務配置采用的注解的方式來配置傳播性配置，此類沒有在spring傳播配置里面，所以不能用自動裝配的方式來配置
    private static FaxRecvArchiveCtrl faxRecvArchiveCtrl = AppContextAware.getBean(FaxRecvArchiveCtrl.class);
 
    private FaxRecvArchiveDTO faxRecvArchiveDTO;
     
    /**
     *  CountDownLatch是一個同步輔助類，在一組線程在執行操作之前，允許一個或多線程處於等待
     *  主要方法
     *          public CountDownLatch(int count);
     *          public void countDown();
     *          public void await() throws InterruptedException
     *
     *          構造方法參數指定了計數的次數
     *          countDown方法，當前線程調用此方法，則計數減一
     *          awaint方法，調用此方法會一直阻塞當前線程，直到計時器的值為0
     * 
     */ 
    private CountDownLatch latch;
     
      
    public ArchiveTask(FaxRecvArchiveDTO faxRecvArchiveDTO, CountDownLatch latch) {
        this.faxRecvArchiveDTO = faxRecvArchiveDTO;
        this.latch = latch;
    }
 
    @Override
    public void run() {
        try {
            faxRecvArchiveCtrl.updateArchiveFileFlag(ServiceFactory.getCurrentSessionId(), faxRecvArchiveDTO);
        } catch (Exception ex) {
            logger.debug("["+this.faxRecvArchiveDTO.getFaxKey()+"]線程執行異常，錯誤信息為："+ex.getMessage());
        } finally{
            logger.debug("線程執行完："+this.faxRecvArchiveDTO.getFaxKey());
            latch.countDown();
        }
    }
}

 四、調用線程池操作

public class EasyFaxArchiveFileMgr {
	/**
	 * 日志
	 */
	Logger logger = LoggerFactory.getLogger(EasyFaxArchiveFileMgr.class);

	/**
	 * 線程池數量
	 */
	private int ThreadNum = 5;
	
	
	private static FaxRecvArchiveCtrl faxRecvArchiveCtrl = AppContextAware.getBean(FaxRecvArchiveCtrl.class);
	
	private static List<FaxRecvArchiveDTO> noArchiveList = new ArrayList<FaxRecvArchiveDTO>();


	public void archiveFile() throws ShineException{
		noArchiveList = faxRecvArchiveCtrl.getFaxRecvNoArchiveFile();
		
		ExecutorService executorService = Executors.newFixedThreadPool(ThreadNum);

		List<ArchiveTask> taskList = new ArrayList<ArchiveTask>();
		synchronized (noArchiveList) {
			while(CollectionUtils.isEmpty(noArchiveList) == false) {
				
				try {
					//定義計數器
					int countLatch = (noArchiveList.size() > ThreadNum) ? ThreadNum :noArchiveList.size();
					
					CountDownLatch latch = new CountDownLatch(countLatch);
					
					//組織任務
					for(int i = 0; i < ThreadNum; i++){
						if(CollectionUtils.isEmpty(noArchiveList) == false) {
							taskList.add(new ArchiveTask(noArchiveList.remove(0),latch));
						}else{
							break;
						}
					}
					//提交任務
					if (CollectionUtils.isEmpty(taskList) == false) {
						for (int i = 0, size = taskList.size(); i < size; i++) {
							executorService.submit(taskList.get(i));
						}
					}//等待所有線程都執行完
					latch.await();
				} catch(Exception ex) {
					logger.error("線程池處理出錯，原因："+ex.getMessage());
				} finally {
					taskList.clear();
				}
                                //關閉線程連接池
				executorService.shutdown();
			}
		}
		
	}
}

五.spring配置

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
           http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
           http://www.springframework.org/schema/context
           http://www.springframework.org/schema/context/spring-context-2.5.xsd">
	
	<bean id="timerFactory" class="org.springframework.scheduling.timer.TimerFactoryBean">
        <property name="scheduledTimerTasks">
            <list>
                <ref bean="archiveFileScheduler"/>
            </list>
        </property>
    </bean>

    <bean id="archiveFileScheduler" class="org.springframework.scheduling.timer.ScheduledTimerTask">
        <property name="delay">
            <!-- 啟動30秒后開始運行 -->
            <value>30000</value>
        </property>
        <property name="period">
            <!-- 每10秒運行 -->
            <value>10000</value>
        </property>
        <property name="timerTask">
            <ref bean="archiveFileHandleMethodInvoker" />
        </property>
    </bean>
    
    <bean id="archiveFileHandleMethodInvoker" class="org.springframework.scheduling.timer.MethodInvokingTimerTaskFactoryBean">
        <property name="targetObject">
            <ref bean="com.shine.emofs.thirdparty.easyfax.ctrl.EasyFaxArchiveFileMgr" />
        </property>
        <property name="targetMethod">
            <value>archiveFile</value>
        </property>
    </bean>
</beans>

六、參考：

  ExecutorService線程連接池：http://www.itzhai.com/the-executorservice-common-method-newfixedthreadpool-of-create-fixed-size-thread-pool.html#read-more