<servlet>
    <servlet-name>jspDefault</servlet-name>
    <servlet-class>com.xxx.JspDefault</servlet-class>
    </servlet>
    <servlet-mapping>
    <servlet-name>jspDefault</servlet-name>
    <url-pattern>/jsp</url-pattern>
    </servlet-mapping>

---------------------

public class JspDefault extends HttpServlet{
    protected void doGet(HttpServletRequest request, HttpServletResponse response)  
      throws ServletException
      , IOException {
        String toUrl = request.getContextPath()+"/jsp/myIndex.jsp";
        response.sendRedirect(toUrl);
    }
}

------解决方案--------------------

整上一个过滤器  
public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
HttpServletResponse res = (HttpServletResponse)response;
HttpServletRequest req = (HttpServletRequest)request;
//判断一下 请求字符串 为http://localhost:8080/Item/jsp
//req.getRequestDispatcher("/login.do?method=loginIn").forward(req, res);
//跳到你指定的页面上 上面可以参考
chain.doFilter(request, response);
}

------解决方案--------------------
req.getRequestDispatcher("/login.do?method=loginIn").forward(req, res);  

chain.doFilter(request, response);