java 多线程（ThreadPoolExecutor）

ThreadPoolExecutor是常用的java线程池实现，之前的项目中也一直有用到，本文记录两个基本的例子和参数设置。

例子1：

public class Thread1 {

    public void ThreadOperation(){

        BlockingQueue queue = new LinkedBlockingQueue();

        ThreadPoolExecutor executer 

            = new ThreadPoolExecutor(3,6,1,TimeUnit.DAYS,queue);

        

        for(int i = 0; i < 10; i++){

            executer.execute(new Runnable(){



                @Override

                public void run() {

                    // TODO Auto-generated method stub

                    try {

                        Thread.sleep(1000);

                    } catch (InterruptedException e) {

                        // TODO Auto-generated catch block

                        e.printStackTrace();

                    }

                    System.out.println("execute:");

                }

            });

           

        executer.shutdown();

    }

}

例子2：

public class Thread2 {

    

    class MyFactory implements ThreadFactory{



        @Override

        public Thread newThread(Runnable r) {

            // TODO Auto-generated method stub

            System.out.println("newThread");

            Thread t = new Thread(r);

            t.setName("Fredric");

            return t;

        }    

    }

    

    public void ThreadOperation(){

        BlockingQueue queue = new LinkedBlockingQueue(4);//特地限制了缓存队列的大小

        ThreadPoolExecutor executor 

            = new ThreadPoolExecutor(3,//初始线程数

                    6,//当缓存满时创建的最大线程数

                    100,//多余线程等待任务的时间

                    TimeUnit.MILLISECONDS,//时间的单位

                    queue,

                    new MyFactory());

        

        for(int i = 0; i < 10; i++){

            executor.execute(new Runnable(){



                @Override

                public void run() {

                    try {

                        Thread.sleep(1000);

                    } catch (InterruptedException e) {

                        e.printStackTrace();

                    }

                    System.out.println("executer"+

                            Thread.currentThread().getName());

                }    

            });

        }

        

        try {

            Thread.sleep(3000);

        } catch (InterruptedException e1) {

            e1.printStackTrace();

        }

        

        for(int i = 0; i < 5; i++){

            executor.execute(new Runnable(){



                @Override

                public void run() {

                    try {

                        Thread.sleep(1000);

                    } catch (InterruptedException e) {

                        e.printStackTrace();

                    }

                    System.out.println("executer "+" next "+

                            Thread.currentThread().getName());

                }    

            });

        }        

        executor.shutdown();        

    }

}

第二个例子证明参数的使用，其打印如下：

newThread
newThread
newThread //系统启动时的核心线程 3个
newThread
newThread
newThread //当缓存队列满时，增加线程至 10个
executerFredric
executerFredric
executerFredric
executerFredric
executerFredric
executerFredric
executerFredric
executerFredric
executerFredric
executerFredric 
newThread
newThread
newThread //超时后，新增的3个线程被销毁，因此被重新创建
executer next Fredric
executer next Fredric
executer next Fredric
executer next Fredric
executer next Fredric