java实现计数器限流

java实现计数器限流

AtomicInteger方式，代码实现

package com.example.demo.limit;

import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

public class AtomicIntegerServiceTask implements Runnable{

    private static AtomicInteger count = new AtomicInteger(0);

    private String serviceName;

    AtomicIntegerServiceTask(String serviceName){
        this.serviceName = serviceName;
    }

    public void run() {
        if (count.get() >= 5) {
            System.out.println("请求用户过多，请稍后在试！");
        } else {
            try {
                System.out.println("Thread " + serviceName + " is working");
                count.incrementAndGet();
                Thread.sleep(1000);
                System.out.println("Thread " + serviceName + " is over");
            } catch (InterruptedException e) {
                System.out.println("error ...." + e.getMessage());
            }
        }
    }
}

测试下AtomicIntegerRateLimiter

package com.example.demo.limit;

import lombok.extern.slf4j.Slf4j;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.SynchronousQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
@Slf4j
public class AtomicIntegerRateLimiterDemo {

    public static void main(String[] args){
        ExecutorService executor = new ThreadPoolExecutor(0, Integer.MAX_VALUE, 60L, TimeUnit.SECONDS, new SynchronousQueue<Runnable>());
        for(int i = 1 ; i <= 100 ; i++){
            AtomicIntegerServiceTask serviceTask = new AtomicIntegerServiceTask("task" + i);
            executor.submit(serviceTask);
        }
    }
}

Semaphore方式，代码实现

package com.example.demo.limit;

import java.util.concurrent.Semaphore;

public class SemaphoreServiceTask implements Runnable{

    private static Semaphore semphore = new Semaphore(3);

    private String serviceName;

    SemaphoreServiceTask(String serviceName){
        this.serviceName = serviceName;
    }
    @Override
    public void run(){
        if(semphore.getQueueLength() > 10){
            System.out.println("当前等待排队的任务数大于10，请稍候再试...");
            return;
        }
        try {
            semphore.acquire();
            System.out.println("Thread " + serviceName + " is working");
            Thread.sleep(1000);
            System.out.println("Thread " + serviceName + " is over");
        } catch (InterruptedException e) {
            e.printStackTrace();
        }finally {
            semphore.release();
        }
    }
}

测试下SemaphoreCountLimiter

package com.example.demo.limit;

import lombok.extern.slf4j.Slf4j;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.SynchronousQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
@Slf4j
public class SemaphoreCountLimiterDemo {

    public static void main(String[] args){
        ExecutorService executor = new ThreadPoolExecutor(0, Integer.MAX_VALUE, 60L, TimeUnit.SECONDS, new SynchronousQueue<Runnable>());
        for(int i = 1 ; i <= 100 ; i++){
            SemaphoreServiceTask serviceTask = new SemaphoreServiceTask("task" + i);
            executor.submit(serviceTask);
        }
    }
}