Java线程池小拓展

妖狐艹你老母 2021-09-27 21:06 220阅读 0赞

**线程池的介绍**  
1 常用的 池化技术  
C3P0  
DBCP  
2 线程池的衍生  
频繁的创建线程对象和多线程之间进行上下文切换,是非常耗时间和资源的所以JDK1.5中提出了线程池技术  
3 使用线程池  
Exector  
4 线程池的创建  
1 创建一个固定大小的线程池 ( **最常用的方法** )

> ExecutorService pool = Executors.newFixedThreadPool(2);  
> Runnable task = new Runnable() \{  
> @Override  
> public void run() \{  
> while (true) \{  
> try \{  
> Thread.sleep(1000);  
> \} catch (InterruptedException e) \{  
> e.printStackTrace();  
> \}  
> System.out.println(Thread.currentThread().getName());  
> \}  
> \}  
> \};  
> pool.execute(task);  
> pool.execute(task);  
> pool.execute(task);//线程池的带下只有两个 现在这个任务在其等待队列中排队等候

2  创建可变大小的线程池

> ExecutorService pool = Executors.newCachedThreadPool();  
> Runnable task = new Runnable() \{  
> @Override  
> public void run() \{  
> while (true) \{  
> try \{  
> Thread.sleep(1000);  
> \} catch (InterruptedException e) \{  
> e.printStackTrace();  
> \}  
> System.out.println(Thread.currentThread().getName());  
> \}  
> \}  
> \};  
> pool.execute(task);  
> pool.execute(task);  
> pool.execute(task);

3 创建独立任务的线程池

> ExecutorService pool = Executors.newSingleThreadExecutor();  
> Runnable task = new Runnable() \{  
> @Override  
> public void run() \{  
> while (true) \{  
> try \{  
> Thread.sleep(1000);  
> \} catch (InterruptedException e) \{  
> e.printStackTrace();  
> \}  
> System.out.println(Thread.currentThread().getName());  
> \}  
> \}  
> \};  
> pool.execute(task);  
> pool.execute(task);  
> pool.execute(task);

4 创建可调度的线程池

> ScheduledExecutorService threadPool = Executors.newScheduledThreadPool(2);  
> Runnable task = new Runnable() \{  
> @Override  
> public void run() \{  
> while (true) \{  
> try \{  
> Thread.sleep(1000);  
> \} catch (InterruptedException e) \{  
> e.printStackTrace();  
> \}  
> System.out.println(Thread.currentThread().getName());  
> \}  
> \}  
> \};  
> threadPool.schedule(task, 2000, TimeUnit.MILLISECONDS);