通过调用Executors类的静态newCachedThreadPool()方法可以获得缓存的线程池。
语法
ExecutorService executor = Executors.newCachedThreadPool();
其中，
newCachedThreadPool()方法创建一个具有可扩展线程池的执行器。- 这样的执行者适合于发起许多短命的任务的应用程序。
示例
以下TestThread程序在线程环境中显示了newCachedThreadPool()方法的用法。
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
public class TestThread {
public static void main(final String[] arguments) throws InterruptedException {
ExecutorService executor = Executors.newCachedThreadPool();
// Cast the object to its class type
ThreadPoolExecutor pool = (ThreadPoolExecutor) executor;
//Stats before tasks execution
System.out.println("Core threads: " + pool.getCorePoolSize());
System.out.println("Largest executions: "
+ pool.getLargestPoolSize());
System.out.println("Maximum allowed threads: "
+ pool.getMaximumPoolSize());
System.out.println("Current threads in pool: "
+ pool.getPoolSize());
System.out.println("Currently executing threads: "
+ pool.getActiveCount());
System.out.println("Total number of threads(ever scheduled): "
+ pool.getTaskCount());
executor.submit(new Task());
executor.submit(new Task());
//Stats after tasks execution
System.out.println("Core threads: " + pool.getCorePoolSize());
System.out.println("Largest executions: "
+ pool.getLargestPoolSize());
System.out.println("Maximum allowed threads: "
+ pool.getMaximumPoolSize());
System.out.println("Current threads in pool: "
+ pool.getPoolSize());
System.out.println("Currently executing threads: "
+ pool.getActiveCount());
System.out.println("Total number of threads(ever scheduled): "
+ pool.getTaskCount());
executor.shutdown();
}
static class Task implements Runnable {
public void run() {
try {
Long duration = (long) (Math.random() * 5);
System.out.println("Running Task! Thread Name: " + Thread.currentThread().getName());
TimeUnit.SECONDS.sleep(duration);
System.out.println("Task Completed! Thread Name: "+ Thread.currentThread().getName());
}
catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
这将产生以下结果 -
Core threads: 0
Largest executions: 0
Maximum allowed threads: 2147483647
Current threads in pool: 0
Currently executing threads: 0
Total number of threads(ever scheduled): 0
Core threads: 0
Largest executions: 2
Maximum allowed threads: 2147483647
Current threads in pool: 2
Currently executing threads: 2
Total number of threads(ever scheduled): 2
Running Task! Thread Name: pool-1-thread-1
Running Task! Thread Name: pool-1-thread-2
Task Completed! Thread Name: pool-1-thread-2
Task Completed! Thread Name: pool-1-thread-1
