package com.vxichina.cluster.persistence.thread.pool; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; /** * 第一种线程池newCachedThreadPool * 创建一个可缓存线程池,如果线程池长度超过处理需要,可灵活回收空闲线程,若无可回收,则新建线程。 * @author admin * */ public class ThreadPoolOne { public static void main(String[] args) { ExecutorService threadPool=Executors.newCachedThreadPool();//理论上有无限个线程,实际使用时会重复利用已有的空闲线程 //for #s for (int i = 0; i < 100; i++) { final int index=i; //System.out.println("for循环中index的值="+index); try { Thread.sleep(i*100);//触发操作系统立刻重新进行一次CPU竞争 } catch (InterruptedException e) { e.printStackTrace(); } threadPool.execute(new Runnable() { @Override public void run() { System.out.println("index的值="+index+", 当前线程:id="+Thread.currentThread().getId()+", name="+Thread.currentThread().getName()); } }); } //for #e } }
2、newFixedThreadPool
package com.vxichina.cluster.persistence.thread.pool; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; /** * 第一种线程池newFixedThreadPool * 创建一个定长线程池,可控制线程最大并发数,超出的线程会在队列中等待。 * @author admin * */ public class ThreadPoolTwo { public static void main(String[] args) { ExecutorService threadPool=Executors.newFixedThreadPool(3);//只设置3个线程 //for #s for (int i = 0; i < 1000; i++) { final int index=i; //System.out.println("for循环中index的值="+index); threadPool.execute(new Runnable() { @Override public void run() { System.out.println("index的值="+index+", 当前线程:id="+Thread.currentThread().getId()+", name="+Thread.currentThread().getName()); try { Thread.sleep(3000);//触发操作系统立刻重新进行一次CPU竞争 } catch (InterruptedException e) { e.printStackTrace(); } } }); } //for #e } }
3、newScheduledThreadPool
package com.vxichina.cluster.persistence.thread.pool; import java.util.Calendar; import java.util.Date; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.ScheduledExecutorService; import java.util.concurrent.TimeUnit; /** * 第一种线程池newScheduledThreadPool * 创建一个定长线程池,支持定时及周期性任务执行。 * @author admin * */ public class ThreadPoolThree { public static void main(String[] args) { //ScheduledExecutorService比Timer更安全,功能更强大 ScheduledExecutorService threadPool=Executors.newScheduledThreadPool(3);//只设置3个线程 //#s threadPool.schedule(new Runnable() { @Override public void run() { System.out.println("我是延迟5秒后执行的哦"); } }, 5, TimeUnit.SECONDS);//表示延迟5秒执行 //#e //#s threadPool.scheduleAtFixedRate(new Runnable() { @Override public void run() { System.out.println("我是延迟5秒后每2秒执行一回"+Calendar.getInstance().getTime().getHours()+":"+Calendar.getInstance().getTime().getMinutes()+":"+Calendar.getInstance().getTime().getSeconds()); } }, 5, 2, TimeUnit.SECONDS);//延迟5秒后每2秒执行一次 //#e //#s threadPool.scheduleWithFixedDelay(new Runnable() { @Override public void run() { System.out.println("输出"+Calendar.getInstance().getTime().getHours()+":"+Calendar.getInstance().getTime().getMinutes()+":"+Calendar.getInstance().getTime().getSeconds()); } }, 2, 5, TimeUnit.SECONDS);//初始延迟2秒后面每个延迟5秒执行 //#e } }
4、newSingleThreadExecutor
package com.vxichina.cluster.persistence.thread.pool; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; /** * 第一种线程池newSingleThreadExecutor * 创建一个单线程化的线程池,它只会用唯一的工作线程来执行任务,保证所有任务按照指定顺序(FIFO, LIFO, 优先级)执行。 * @author admin * */ public class ThreadPoolFour { public static void main(String[] args) { ExecutorService threadPool=Executors.newSingleThreadExecutor();//单一线程,相当于顺序执行各个任务 //for #s for (int i = 0; i < 1000; i++) { final int index=i; threadPool.execute(new Runnable() { @Override public void run() { System.out.println("index的值="+index+", 当前线程:id="+Thread.currentThread().getId()+", name="+Thread.currentThread().getName()); try { Thread.sleep(1000);//触发操作系统立刻重新进行一次CPU竞争 } catch (Exception e) { e.printStackTrace(); } } }); } //for #e } }