了解这几个接口Executor，
接口ExecutorService继承 Executor，
ThreadPoolExecutor，Executors；
Executors 工厂类 用于创建各种类型的线程池。其包含的方法
创建固定个数线程的线程池
public static ExecutorService newFixedThreadPool(int nThreads) {
return new ThreadPoolExecutor(nThreads, nThreads,
0L, TimeUnit.MILLISECONDS,
new LinkedBlockingQueue<Runnable>());
}创建一个线程的线程池
public static ExecutorService newSingleThreadExecutor() {
return new FinalizableDelegatedExecutorService
(new ThreadPoolExecutor(1, 1,
0L, TimeUnit.MILLISECONDS,
new LinkedBlockingQueue<Runnable>()));
}Creates a thread pool that creates new threads as needed, but will reuse previously constructed threads when they are
available.
public static ExecutorService newCachedThreadPool() {
return new ThreadPoolExecutor(0, Integer.MAX_VALUE,
60L, TimeUnit.SECONDS,
new SynchronousQueue<Runnable>());
}使用过程
内核数量，一般创建线程的个数为内核个数+1 最大线程数为内核数量*2 +1
int processors = Runtime.getRuntime().availableProcessors();
System.out.println("cpu 数量："+processors); //创建一个线程池，包含最多两个线程的固定线程池
ExecutorService executorService = Executors.newFixedThreadPool(2);
ThreadPoolExecutor ThreadPool = new ThreadPoolExecutor(2, 2, 0L, TimeUnit.MILLISECONDS, new LinkedBlockingQueue<Runnable>());
ThreadPool.execute(new Runnable() {
@Override
public void run() {
while (true) {
System.out.println("执行ThreadPool线程池");
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
});
//添加了第一个任务...这个任务会一直被执行...
executorService.execute(new Runnable() {
@Override
public void run() {
while (true) {
System.out.println("执行第一个");
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
});
//添加第二个任务，被执行三次停止...
executorService.execute(new Runnable() {
@Override
public void run() {
int i = 0;
while (true) {
i++;
System.out.println("执行第二个");
if (i == 3) {
break;
}
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
});
executorService.execute(new Runnable() {
@Override
public void run() {
while (true) {
System.out.println("执行第三个");
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}结果如下1：
10-30 15:44:43.287 3967-4102/com.wall.geat.greatapplication I/System.out: 执行ThreadPool线程池
10-30 15:44:43.288 3967-4103/com.wall.geat.greatapplication I/System.out: 执行第一个
10-30 15:44:43.289 3967-4104/com.wall.geat.greatapplication I/System.out: 执行第二个
10-30 15:44:44.288 3967-4102/com.wall.geat.greatapplication I/System.out: 执行ThreadPool线程池
10-30 15:44:44.289 3967-4103/com.wall.geat.greatapplication I/System.out: 执行第一个
10-30 15:44:44.290 3967-4104/com.wall.geat.greatapplication I/System.out: 执行第二个如下2：
10-30 15:44:45.288 3967-4102/com.wall.geat.greatapplication I/System.out: 执行ThreadPool线程池
10-30 15:44:45.290 3967-4103/com.wall.geat.greatapplication I/System.out: 执行第一个
10-30 15:44:45.290 3967-4104/com.wall.geat.greatapplication I/System.out: 执行第二个
10-30 15:44:45.290 3967-4104/com.wall.geat.greatapplication I/System.out: 执行第三个
10-30 15:44:46.289 3967-4102/com.wall.geat.greatapplication I/System.out: 执行ThreadPool线程池
10-30 15:44:46.290 3967-4103/com.wall.geat.greatapplication I/System.out: 执行第一个
10-30 15:44:46.290 3967-4104/com.wall.geat.greatapplication I/System.out: 执行第三个
10-30 15:44:47.289 3967-4102/com.wall.geat.greatapplication I/System.out: 执行ThreadPool线程池
10-30 15:44:47.290 3967-4103/com.wall.geat.greatapplication I/System.out: 执行第一个
10-30 15:44:47.291 3967-4104/com.wall.geat.greatapplication I/System.out: 执行第三个
10-30 15:44:48.289 3967-4102/com.wall.geat.greatapplication I/System.out: 执行ThreadPool线程池
10-30 15:44:48.291 3967-4103/com.wall.geat.greatapplication I/System.out: 执行第一个
10-30 15:44:48.291 3967-4104/com.wall.geat.greatapplication I/System.out: 执行第三个
10-30 15:44:49.290 3967-4102/com.wall.geat.greatapplication I/System.out: 执行ThreadPool线程池
10-30 15:44:49.291 3967-4103/com.wall.geat.greatapplication I/System.out: 执行第一个
10-30 15:44:49.292 3967-4104/com.wall.geat.greatapplication I/System.out: 执行第三个
10-30 15:44:50.290 3967-4102/com.wall.geat.greatapplication I/System.out: 执行ThreadPool线程池
10-30 15:44:50.292 3967-4104/com.wall.geat.greatapplication I/System.out: 执行第三个
10-30 15:44:50.292 3967-4103/com.wall.geat.greatapplication I/System.out: 执行第一个
10-30 15:44:51.291 3967-4102/com.wall.geat.greatapplication I/System.out: 执行ThreadPool线程池
10-30 15:44:51.292 3967-4103/com.wall.geat.greatapplication I/System.out: 执行第一个
10-30 15:44:51.292 3967-4104/com.wall.geat.greatapplication I/System.out: 执行第三个