chengnl / study Goto Github PK

 实现一个流控程序，控制客户端每秒或者一段时间访问服务端不超过N次，客户端多线程并发请求。

import java.util.Date;
/**
 *@author chengnl
 *@date 2015年2月10日 下午8:52:25
 *@version 1.0
 *@Description:模拟服务
 */
public class MockServer {
    private VisitCount visitCount;
    private int maxLimitVisit=100;  
    public MockServer() {
        this.visitCount=new VisitCount();
    }   
    public int visit(){
         int result=0;
         long time = new Date().getSeconds();
         if(time==this.visitCount.getTime()){
            long count= this.visitCount.getCount().getAndIncrement();
            if(count>this.maxLimitVisit-1)
                result= 1;
         }else{
            synchronized (visitCount) {
                if(time!=this.visitCount.getTime()){
                  this.visitCount.setTime(time);
                  this.visitCount.getCount().set(0);
                }
            }
            long count= this.visitCount.getCount().getAndIncrement();
            if(count>this.maxLimitVisit-1)
                result= 1;
         }
         System.out.println("time="+time+",count="+this.visitCount.getCount()+",result="+result);
         return result;
    }
}

package exercise.concurrency.one.way1;

import java.util.concurrent.atomic.AtomicLong;

/**
 *@author chengnl
 *@date 2015年2月10日 下午8:48:43
 *@version 1.0
 *@Description:访问计数
 */
public class VisitCount {
    private  long time=0;
    private  AtomicLong count= new AtomicLong(0);

    public long getTime() {
        return time;
    }
    public void setTime(long time) {
        this.time = time;
    }
    public AtomicLong getCount() {
        return count;
    }
}

package exercise.concurrency.one.way3;

import java.util.Date;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * @author chengnl
 * @date 2015年2月10日 下午11:34:50
 * @version 1.0
 * @Description:TODO类描述
 */
public class MockClient2 {
    final static int MAX_QPS = 10;

    final static Semaphore semaphore = new Semaphore(MAX_QPS);

    final static AtomicInteger accessCount = new AtomicInteger(0);

    public static void main(String[] args) throws Exception {

        // release semaphore thread
        Executors.newScheduledThreadPool(1).scheduleAtFixedRate(new Runnable() {
            @Override
            public void run() {
                semaphore.release(accessCount.getAndSet(0));
            }
        }, 1000, 1000, TimeUnit.MILLISECONDS);

        // lots of concurrent calls: 100 * 1000
        ExecutorService pool = Executors.newFixedThreadPool(100);
        for (int i = 100; i > 0; i--) {
            final int x = i;
            pool.submit(new Runnable() {
                @Override
                public void run() {
                    for (int j = 1000; j > 0; j--) {
                        try {
                            Thread.sleep(5);
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                        semaphore.acquireUninterruptibly(1);
                        accessCount.incrementAndGet();

                        remoteCall(x, j);
                    }
                }
            });
        }

        pool.shutdown();
        pool.awaitTermination(1, TimeUnit.HOURS);
        System.out.println("done");
    }

    private static void remoteCall(int i, int j) {
        System.out.println(String.format("%s – %s: %d %d", new Date(),
                Thread.currentThread(), i, j));
    }
}

package exercise.concurrency.one.way2;

import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;

/**
 *@author chengnl
 *@date 2015年2月10日 下午8:52:25
 *@version 1.0
 *@Description:模拟服务
 */
public class MockServer {
    private AtomicLong count = new AtomicLong(100);

    public MockServer() {
        Executors.newSingleThreadScheduledExecutor().scheduleAtFixedRate(new Runnable(){

            @Override
            public void run() {

                count.set(100);
                System.out.println("1 秒过去了");
            }

        }, 1, 1, TimeUnit.SECONDS);
    }

    public int visit(){
         if(count.decrementAndGet()>0){
             System.out.println("允许访问。"+count.longValue());
             return 0;
         }
         return 1;
    }
}