Java CookBook--Using a BlockingBuffer--by Tim O'Brien 整理by博主

  BlockingBuffer的使用:在操作对象前需要等待输入的情况要用到BlockingBuffer

  Maven项目使用前，加入下述依赖在你的项目pom.xml中。

<dependency><groupId>commons-collections</groupId><artifactId>commons-collections</artifactId><version>3.2.1</version></dependency>

  在多线程的情况下，才能验证BlockingBuffer，以下是一个简单的BlockingBuffer使用实例，主线程往BlockingBuffer中添加对象，而listenerThread则remove该对象，此时BlockingBuffer的作用显现，虽然listenerThread线程先一步启动，BlockingBuffer也会先等待对象的加入，再执行删除，故不会报错。

import org.apache.commons.collections.Buffer;import org.apache.commons.collections.buffer.BlockingBuffer;import org.apache.commons.collections.buffer.BoundedFifoBuffer;public class BufferTest {public static void main(String[] args) {       /*        * Your system needs to wait for input and act on an object the moment it is        * added to a Buffer. To achieve this, you need your application to block until        * input is received, use BlockingBuffer to decorate an instance of Buffer.        * when a process calls get() or remove() on a buffer decorated with BlockingBuffer,        * the decorated buffer does not return a value until it has an object to return.               *///create a Blocking BufferBuffer buffer=BlockingBuffer.decorate(new BoundedFifoBuffer());//Create Thread to continuously remove() from the previous BufferBufferListener listener=new BufferListener(buffer);Thread listenerThread=new Thread(listener);/* * The listenerThread will block on a call to buffer.remove() within the run()  * method of BufferListener, an object that runs in a separate thread and  * waits for objects to be added to a BlockingBuffer. */listenerThread.start();buffer.add("Hello World!");buffer.add("Goodbye,Y'all.");}}

  BufferListner的实现：

import org.apache.commons.collections.Buffer;/** * a BlockingBuffer can only be demonstrated by an example * that deals with multiple threads.BufferListener implements * Runnable defined for this. *  * */public class BufferListener implements Runnable {    private Buffer buffer;    public BufferListener(Buffer buffer){    this.buffer=buffer;    }@Overridepublic void run() {while(true){String message=(String)buffer.remove();System.out.println(message);}}}

结果如下：

Hello World!Goodbye,Y'all.