jsp网页简单计算器---菜鸟级别的

package edu.nkd.servlet; import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class servletCal extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); PrintWriter out = response.getWriter(); String num1=request.getParameter("num1"); String num2=request.getParameter("num2"); String pro=request.getParameter("pro"); Cal cal=new Cal(); cal.setNum1(Integer.parseInt(num1)); cal.setNum2(Integer.parseInt(num2)); double result=0; if(pro.equals("+")) { result=cal.add(); }else if(pro.equals("-")) { result=cal.sub(); }else if(pro.equals("*")) { result=cal.mult(); }else if(pro.equals("/")) { result=cal.div(); } request.setAttribute("result", result); request.getRequestDispatcher("/servletResult").forward(request, response); } }