Java-----关于线程池的使用

package thread;

import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
//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
public class ThreadPoolExceutorTest1 {
    public static void main(String[] args) {
        ExecutorService cachedThreadPoll = Executors.newCachedThreadPool();
        for (int i = 0; i < 10; i++) {
            final int index = 1;
            try {
                Thread.sleep(index * 10);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            cachedThreadPoll.execute(new Runnable() {
                public void run() {
                    System.out.println(index);
                }
            });
        }
    }
}

package thread;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
//创建定长线程池，可控线程最大并发数，超出线程会在队列中等待
public class ThreadPoolExecutorTest2 {
    public static void main(String []args) {
        ExecutorService fixedThreadPool=Executors.newFixedThreadPool(3);
        for(int i=0;i<10;i++) {
            final int index=1;
            fixedThreadPool.execute(new Runnable() {
                public void run() {
                    try {
                        System.out.println(index);
                        Thread.sleep(2000);
                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            });
        }
    }
}

package thread;

import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
//创建定长线程池，支持定时及周期性任务执行，延迟执行示例如下(3m后执行)
public class ThreadPoolExecutorTest3 {
    public static void main(String []args) 
    {
        ScheduledExecutorService scheduledThreadPool=Executors.newScheduledThreadPool(5);
        scheduledThreadPool.schedule(new Runnable() {
            public void run() {
                System.out.println("this is 3 demo");
            }
        },3,TimeUnit.MILLISECONDS);
    }
}

package thread;

import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
//定期执行 延迟1秒后，3秒执行一次
public class ThreadPoolExecutorTest35 {
    public static void main(String []args) 
    {
        ScheduledExecutorService scheduledThreadPool=Executors.newScheduledThreadPool(5);
        scheduledThreadPool.scheduleAtFixedRate(new Runnable() {
            public void run() {
                System.out.println("this is 3 demo");
            }
        },1,3,TimeUnit.MILLISECONDS);
    }
}

package thread;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
//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。示例代码如下
public class ThreadPoolExecutorTest4 {
    public static void main(String [] args) {
        ExecutorService singleThreadExecutor= Executors.newSingleThreadExecutor();
        for(int i=0;i<10;i++) {
            final int index=i;
            singleThreadExecutor.execute(new Runnable() {
                public void run() {
                    try {
                        System.out.println(index);
                        Thread.sleep(2000);
                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            });
        }
    }
}

package thread;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
//可以使用JDK自带的监控工具来监控我们创建的线程数量，运行一个不终止的线程，创建指定量的线程，来观察：
public class ThreadPoolExecutorTest45 {
    public static void main(String[] args) {
        ExecutorService singleThreadExecutor = Executors.newCachedThreadPool();
        for (int i = 0; i < 100; i++) {
            final int index = i;
            singleThreadExecutor.execute(new Runnable() {
                public void run() {
                    try {
                        while (true) {
                            System.out.println(index);
                            Thread.sleep(10 * 1000);
                        }
                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            });
            try {
                Thread.sleep(500);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
}