java - 从另一个 jsp 文件调用 JSP 函数

Question

我在 jsp 上创建了一个简单的应用程序..

在我的全局函数 jsp 文件中，我创建了如下函数:

<%! public double calcB(double w, double h){
                double B = 0;

                return B = (w / (h * h));

            }


            public String calcClassif(double B){
                String classifi = null;

                  if(B >= 30)
                      classif = "Obese";
                  else if(B >= 25)
                      classif = "Overweight";
                  else if(B >= 18.5)
                      classif = "Normal";
                  else 
                      classif = "Underweight";

                  return classif;

            }

        %>

现在在我的 index.jsp 文件中，我编写了以下内容:

<%@include file = "globalFunctions.jsp" %>

        <% Boolean submitted = Boolean.parseBoolean(request.getParameter("isSubmitted"));
           double we = 0, he = 0;
           if(submitted){

               weight = Double.parseDouble(request.getParameter("w"));
               height = Double.parseDouble(request.getParameter("h"));                                 
           }
        %>

        <h3>BMI Calculator</h3>

        <form action = "index.jsp" method = "post">
            <input type ="hidden" name = "isSubmitted" value = "true"> 
            Weight: <input type = "text" name = "w"> <br> <br>
            Height: <input type = "text" name = "h"> <br> <br>
            <input type = "submit" value = "Compute"> <br> <br>

            BMI: <%= calcBMI(we, he) %> <br> <br>
            Classification: <%= classification %>
    </form>

当我执行应用程序时，分类不起作用。如何调用该方法来显示正确的分类？请帮忙..谢谢

Answer 1

您永远不会将值分配给分类。你可以试试这个:

<%@include file = "globalFunctions.jsp" %>

        <% Boolean submitted = Boolean.parseBoolean(request.getParameter("isSubmitted"));
           double we = 0, he = 0;
           if(submitted){
               weight = Double.parseDouble(request.getParameter("w"));
               height = Double.parseDouble(request.getParameter("h"));
               bmi = calcBMI(we, he);
               classification = calcClassif(bmi);
           }
        %>

        <h3>BMI Calculator</h3>

        <form action = "index.jsp" method = "post">
            <input type ="hidden" name = "isSubmitted" value = "true"> 
            Weight: <input type = "text" name = "w"> <br> <br>
            Height: <input type = "text" name = "h"> <br> <br>
            <input type = "submit" value = "Compute"> <br> <br>

            BMI: <%= bmi %> <br> <br>
            Classification: <%= classification %>
    </form>