啥都別說了，上程式碼：

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadPoolExecutor;

public class ExecutorTest {
	
	private static Integer pages=1;
	private static boolean exeFlag=true;

	public static void main(String[] args) {
		ExecutorService executorService=Executors.newFixedThreadPool(10);//建立ExxcutorService執行緒池
		while(exeFlag){
			if(pages<=100){
				executorService.execute(new Runnable(){

					@Override
					public void run() {
						// TODO Auto-generated method stub
						System.out.println("爬取了第"+pages+"網頁....");
						pages++;
					}
					
				});
			}else{
				if(((ThreadPoolExecutor)executorService).getActiveCount()==0){
					//活動執行緒個數為o
					executorService.shutdown();
					exeFlag=false;
					System.out.println("爬蟲任務已經完成");
				}
			}
			try {
				Thread.sleep(100);
			} catch (InterruptedException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		
	}
}