Java之创建线程池的四种方式

1.线程池的核心参数

2.Java之创建线程池的四种方式

package threadPool;

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

/**
 * @author tian
 * @Package threadPool
 * @date 2022/9/6 16:35
 * @description 创建线程池的四种方式
 * 1.使用newCachedThreadPool-可缓存线程池
 * 2.newFixedThreadPool 指定工作线程数量的线程池
 * 3.newSingleThreadPool 只创建唯一的工作线程来执行任务
 * 4.newScheduledThreadPool 创建一个定长的线程池，而且支持定时
 * 且周期性任务执行
 *
 */
public class FourWaysToCreateThreadPool {
// * 1.使用newCachedThreadPool-可缓存线程池
    public static ExecutorService cacheThreadPool = Executors.newCachedThreadPool();
// * 2.newFixedThreadPool 指定工作线程数量的线程池
    public static ExecutorService fixedThreadPool = Executors.newFixedThreadPool(3);
// * 3.newSingleThreadPool 只创建唯一的工作线程来执行任务
    public static ExecutorService singleThreadPool = Executors.newSingleThreadExecutor();
// * 4.newScheduledThreadPool 创建一个定长的线程池，而且支持定时
    public static ScheduledExecutorService scheduledThreadPool = Executors.newScheduledThreadPool(5);

    public static void main(String[] args) {
        System.out.println("创建线程的四种方式如下");
        createNewCachedThreadPool();
        createNewFixedThreadPool();
        createNewSingleThreadPool();
        createNewScheduledThreadPool();
    }
    /**
     * 1.使用newCachedThreadPool-可缓存线程池
     */
    public static void  createNewCachedThreadPool(){
        System.out.println("1.使用newCachedThreadPool-可缓存线程池");
        for (int i = 0; i < 10; i++) {
            final int index = i;
            try {
                Thread.sleep(index * 1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            //创建线程并执行
            cacheThreadPool.execute(new Runnable() {
                @Override
                public void run() {
                    System.out.println(index);
                }
            });
        }
    }
    /**
     * 2.newFixedThreadPool 指定工作线程数量的线程池
     */
    public static void createNewFixedThreadPool(){
        System.out.println("2.newFixedThreadPool 指定工作线程数量的线程池");
        for (int i = 0; i < 10; i++) {
            final int index = i;
            try {
                Thread.sleep(index * 1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            //创建线程并执行
            fixedThreadPool.execute(new Runnable() {
                @Override
                public void run() {
                    System.out.println(index);
                    try {
                        Thread.sleep(50000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            });
        }
    }
    /**
     * 3.newSingleThreadPool 只创建唯一的工作线程来执行任务
     */
    public static void createNewSingleThreadPool(){
        System.out.println("3.newSingleThreadPool 只创建唯一的工作线程来执行任务");
        for (int i = 0; i < 10; i++) {
            final int index = i;
            try {
                Thread.sleep(index * 1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            //创建线程并执行
            singleThreadPool.execute(new Runnable() {
                @Override
                public void run() {
                    System.out.println(index);
                }
            });
        }
    }
    /**
     * 4.newScheduledThreadPool 创建一个定长的线程池，而且支持定时
     * 且周期性任务执行
     *
     */
    public static void createNewScheduledThreadPool(){
        System.out.println("4.newScheduledThreadPool 创建一个定长的线程池，而且支持定时");
        scheduledThreadPool.scheduleAtFixedRate(()->{
            System.out.println("index");
        },1,3, TimeUnit.SECONDS);
    }
}