信号量 java_java信号量限流

1、单机使用Semaphore进行限流：

import java.util.concurrent.Executor;

import java.util.concurrent.Executors;

import java.util.concurrent.Semaphore;

public class SemaphoreLimiter {

private final Semaphore permit = new Semaphore(10, true);

public void process(int i) {

try {

permit.acquire(); // 阻塞的方式

System.out.println("处理逻辑" + i);

} catch (InterruptedException e) {

e.printStackTrace();

}

}

public void processTry(int i) {

boolean acquired = permit.tryAcquire();

if (acquired) {

try {

System.out.println("处理业务逻辑" + i);

} catch (Exception e) {

e.printStackTrace();

} finally {

System.out.println("释放信号量");

permit.release();

}

} else {

System.out.println("降级处理");

}

}

public static void main(String[] args) {

Executor executors = Executors.newFixedThreadPool(50);

SemaphoreLimiter sl = new SemaphoreLimiter();

for (int i = 0; i < 1000; i++) {

final int num = i;

executors.execute(new Runnable() {

@Override

public void run() {

//sl.process(num);

sl.processTry(num);

}

});

}

}

}

使用Semaphore信号量进行限流

accquire tryAcquire release

2 Semaphore实现