JSP使用多线程

spider之中需要使用多线程去抓取网页，本来还有点疑惑，没想到在jsp中使用多线程也很方便。

String site1 = request.getParameter("site1");
	String site2 = request.getParameter("site2");
	String site3 = request.getParameter("site2");

	Spider crawler = new Spider(site1, 20);
	//Thread search = new Thread(crawler);
	System.out.println("Start!");
	System.out.println("result:");
	//search.start();
	crawler.start();
	Spider crawler1 = new Spider(site2, 20);
	crawler1.start();
	Spider crawler2 = new Spider(site3, 20);
	crawler2.start();