/**
 * @Description:
 * @param @param args
 * @return void 返回类型
 */
public static void main(String[] args) {
  // 线程池
  ExecutorService exec = Executors.newCachedThreadPool();
  // 只能5个线程同时访问
  final Semaphore semp = new Semaphore(5);
  // 模拟20个客户端访问
  for (int index = 0; index < 20; index++) {
    final int NO = index;
    Runnable run = new Runnable() {
      public void run() {
        try {
          // 获取许可
          semp.acquire();
          System.out.println("获得Accessing: " + NO);
          Thread.sleep((long) (Math.random() * 10000));
          // 访问完后，释放
          semp.release();
          System.out.println("剩余可用信号-----------------"
              + semp.availablePermits());
        } catch (InterruptedException e) {
          e.printStackTrace();
        }
      }
    };
    exec.execute(run);
  }
  // 退出线程池
  exec.shutdown();
}

获得Accessing: 1
获得Accessing: 5
获得Accessing: 2
获得Accessing: 3
获得Accessing: 0
剩余可用信号-----------------1
获得Accessing: 4
剩余可用信号-----------------1
获得Accessing: 9
剩余可用信号-----------------1
获得Accessing: 8
剩余可用信号-----------------1
获得Accessing: 6
剩余可用信号-----------------1
获得Accessing: 10
剩余可用信号-----------------1
获得Accessing: 11
剩余可用信号-----------------1
获得Accessing: 12
剩余可用信号-----------------1
获得Accessing: 13
剩余可用信号-----------------1
获得Accessing: 7
剩余可用信号-----------------1
获得Accessing: 15
剩余可用信号-----------------1
获得Accessing: 16
剩余可用信号-----------------1
获得Accessing: 17
剩余可用信号-----------------1
获得Accessing: 14
剩余可用信号-----------------1
获得Accessing: 18
剩余可用信号-----------------1
获得Accessing: 19
剩余可用信号-----------------1
剩余可用信号-----------------2
剩余可用信号-----------------3
剩余可用信号-----------------4
剩余可用信号-----------------5

package com.jx.test;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.Pipe;
public class testPipe {
 /**
   * @Description:
   * @param @param args
   * @return void 返回类型
   * @throws IOException
   */
 public static void main(String[] args) throws IOException {
  // 创建一个管道
  Pipe pipe = Pipe.open();
  final Pipe.SinkChannel psic = pipe.sink();
  // 要向管道写数据，需要访问sink通道
  final Pipe.SourceChannel psoc = pipe.source();
  // 从读取管道的数据，需要访问source通道
  Thread tPwriter = new Thread() {
   public void run() {
    try {
     System.out.println("send.....");
     // 创建一个线程，利用管道的写入口Pipe.SinkChannel类型的psic往管道里写入指定ByteBuffer的内容
     int res = psic.write(ByteBuffer
                        .wrap("Hello,Pipe!测试通讯.....".getBytes("utf-16BE")));
     System.out.println("send size:" + res);
    }
    catch (Exception e) {
     e.printStackTrace();
    }
   }
  }
  ;
  Thread tPreader = new Thread() {
   public void run() {
    int bbufferSize = 1024 * 2;
    ByteBuffer bbuffer = ByteBuffer.allocate(bbufferSize);
    try {
     System.out.println("recive.....");
     // 创建一个线程，利用管道的读入口Pipe.SourceChannel类型的psoc将管道里内容读到指定的ByteBuffer中          
     int res = psoc.read(bbuffer);
     //数据未
     System.out.println("recive size:"+res+" Content:" + ByteBufferToString(bbuffer));
    }
    catch (Exception e) {
     e.printStackTrace();
    }
   }
  }
  ;
  tPwriter.start();
  tPreader.start();
 }
 /**
   *ByteBuffer--> String的转换函数
   */
 public static String ByteBufferToString(ByteBuffer content) {
  if (content == null || content.limit() <= 0
            || (content.limit() == content.remaining())) {
   System.out.println("不存在或内容为空！");
   return null;
  }
  int contentSize = content.limit() - content.remaining();
  StringBuffer resultStr = new StringBuffer();
  for (int i = 0; i < contentSize; i += 2) {
   resultStr.append(content.getchar(i));
  }
  return resultStr.toString();
 }
}