ArrayBlockingQueue take()操作

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ArrayBlockingQueue take()操作

 内部类实现Runable接口，通过while(true)循环来执行业务逻辑，首先通过ArrayBlockingQueue.take()来获取需要执行的任务，当队列为空，内部会进入空循环等待，避免过高耗费cpu。

业务类： 

package com.java.innerclassthread ;import java.util.List;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;public class ResourceSynchronizeTaskExecutor {BlockingQueue<String> taskQueue;public ResourceSynchronizeTaskExecutor() {System.out.println("start [RESOURCE SYNCHRONIZE TASK Executor] ...");taskQueue = new ArrayBlockingQueue<String>(200);for (int i = 0; i < 5; i++) {new Thread(new ResourceSynchronizeWorker()).start();try {Thread.sleep(200);} catch (InterruptedException e) {System.out.println("start sync worker err");}}}//	@Overridepublic void execute(String String) {}//	@Overridepublic void execute(List<String> Strings) {for (String String : Strings) {try {taskQueue.put(String);} catch (Exception e) {System.out.println("put queue error");}}}class ResourceSynchronizeWorker implements Runnable {String String;boolean isRunning = true;public ResourceSynchronizeWorker() {}public void run() {System.out.println("sync start...");while (isRunning) {try {System.out.println("xunhuanzhixing................");String = taskQueue.take();} catch (Exception e) {}}}}}

测试类，运行时首先从内存中获取被执行类的实例，如果为空，则实例化： 

package com.java.innerclassthread;import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;public class InnerClassThreadTest {Map<String,ResourceSynchronizeTaskExecutor> cache = new HashMap<String,ResourceSynchronizeTaskExecutor>();public static void main(String[] args) {new InnerClassThreadTest().running(); }public void running(){boolean isRunning = true;while(isRunning){String [] StringActions = new String [(int)(Math.random()*20)];for (int index = 0 ;index <StringActions.length ;index ++){StringActions[index] = "index"+index;}ResourceSynchronizeTaskExecutor ResourceSynchronizeTaskExecutor = getCache ();List<String> theStrings = new ArrayList<String> ();theStrings.add(new String()) ;ResourceSynchronizeTaskExecutor.execute(theStrings);if (StringActions.length < 10){System.out.println("length:"+StringActions.length);try {Thread.sleep(10000);} catch (Exception e) {}}}}public ResourceSynchronizeTaskExecutor getCache(){ResourceSynchronizeTaskExecutor executor = cache.get("ResourceSynchronizeTaskExecutor.class");if (executor == null ){executor = new ResourceSynchronizeTaskExecutor();cache.put("ResourceSynchronizeTaskExecutor.class", executor) ;}return executor ;}}

JDK 中ArrayBlockingQueue take()方法源码：

    public E poll() {final ReentrantLock lock = this.lock;lock.lock();try {return (count == 0) ? null : dequeue();} finally {lock.unlock();}}public E take() throws InterruptedException {final ReentrantLock lock = this.lock;lock.lockInterruptibly();try {while (count == 0)notEmpty.await();return dequeue();} finally {lock.unlock();}}

当使用take 从queue中获取任务时，当任务为空，则释放cpu进行等待；

当使用pull()来从queue中获取任务进行处理时 ，如果count==0，则直接返回null，造成的结果时，如果在while(true){}中执行获取任务操作，会造成cpu占用率100%。