为什么我的Servlet在运行时如出现打开保存的对话框呀

Question

public class SimpleCounter extends HttpServlet 
{
int i = 0;
public void doGet(HttpServletRequest request,HttpServletResponse response)
            throws ServletException,IOException
            {
             response.setContentType("text/html:charset=gb2312");
             PrintWriter out = response.getWriter();
             i++;
             out.println("您是第 " + i +"个访问本页");
            }
}在web.xml中已经配置好! <servlet>
<servlet-name>simpleCounter</servlet-name>
<servlet-class>com.forlink.servletProgram.SimpleCounter</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>simpleCounter</servlet-name>
<url-pattern>/simpleCounter</url-pattern>
</servlet-mapping>
运行
http://localhost:8880/steelsServlet/simpleCounter
出现：打开保存的对话框???????