JUC_02

线程池
好处：
a、降低资源的消耗
b、提高响应速度
c、方便管理
Integer.max(正负21亿)

三大方法

点击查看代码

package org.li;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class ThreadPool {
    public static void main(String[] args) {
        //三大方法
        ///ExecutorService threadPoll= Executors.newSingleThreadExecutor();
        //ExecutorService threadPoll= Executors.newFixedThreadPool(10);
        ExecutorService threadPoll= Executors.newCachedThreadPool();
        try {
            for(int i=0;i<100;i++){
                threadPoll.execute(()->{
                    System.out.println(Thread.currentThread().getName()+"ok");
                });
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        }finally {
            threadPoll.shutdown();
        }

        //7大参数
    }
}

三大方法都是调用threadPoolExecutor

7大参数
corePoolSize
maximumPoolSize
keepAliveTime
unit
workQueue
Executors.defaultThreadFactory()
defaultHandler

点击查看代码

package org.li;

import java.util.concurrent.*;

public class ThreadPool {
    public static void main(String[] args) {
        //三大方法
        ///ExecutorService threadPoll= Executors.newSingleThreadExecutor();
        //ExecutorService threadPoll= Executors.newFixedThreadPool(10);
        //ExecutorService threadPoll= Executors.newCachedThreadPool();
        ExecutorService threadPoll= new ThreadPoolExecutor(2
                , 5
                , 3
                , TimeUnit.SECONDS
                , new LinkedBlockingQueue<>(3)
                ,Executors.defaultThreadFactory()
                ,  new ThreadPoolExecutor.AbortPolicy());   //线程池满了，多的就报错
               //CallerRunsPolicy  //哪里来的去哪里
               //DiscardPolicy  //队列满了，不会抛出异常，
               //DiscardPolicy  //队列满了，不会抛出异常，
          //ThreadPoolExecutor.DiscardOldestPolicy()  满了之后会尝试和第一个竞争
        try {
            for(int i=0;i<8;i++){
                threadPoll.execute(()->{
                    System.out.println(Thread.currentThread().getName()+"ok");
                });
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        }finally {
            threadPoll.shutdown();
        }

        //7大参数
    }
}