jsp 知识点总结

小鱼儿 2023-06-01 11:24 29阅读 0赞

## JSP 入门案例（计算器的实现） ##

对于jsp 学习的一些总结

1.使用Dreamweaver 搭建网页

<table> 
 <tbody> 
  <tr> 
   <td colspan="2"><h1>计算器</h1></td> 
  </tr> 
  <tr> 
   <td>第一个数字</td> 
   <td> </td> 
  </tr> 
  <tr> 
   <td>符号</td> 
   <td>+ - * / </td> 
  </tr> 
  <tr> 
   <td>第二个数字</td> 
   <td></td> 
  </tr> 
  <tr> 
   <td colspan="2"> 
    <div> 
    </div></td> 
  </tr> 
 </tbody> 
</table>

<form id="form1" name="form1" method="post" action="index.jsp?action=Do ">  //注意form 调单后面的acton 标签，其Do会成为action的参数被提交，验证时候，名为acton.值为Do
      <table width="335" height="309" border="1" align="center">
        <tr>
          <td colspan="2"><h1 align="center">计算器</h1></td>
        </tr>
        <tr>
          <td width="113">第一个数字</td>
          <td width="210">
          <input name="firstNumber" type="text" id="textfield" size="30" /></td>
        </tr>
        <tr>
          <td>符号</td>
          <td><input type="radio" name="radio" id="radio" value="1" />
          <label for="radio">+
            <input type="radio" name="radio" id="radio2" value="2" />
          -</label>
          <input type="radio" name="radio" id="radio3" value="3" />
          <label for="radio3">*</label>
          <input type="radio" name="radio" id="radio4" value="4" />
          <label for="radio4">/</label>
          </td>
        </tr>
        <tr>
          <td>第二个数字</td>
          <td><input name="secondNumber" type="text" id="textfield2" size="30" /></td>
        </tr>
           <tr>
          <td colspan="2"><div align="center">
            <input type="submit" name="button" id="button" value="提交" />
              <input type="reset" name="button2" id="button2" value="重置" />
          </div></td>
        </tr>
      </table>
    </form>

2.使用JSP 获取参数并处理表单

()

//jsp:useBean 对java代码的获取
    scope 标签：作用于整个页面
    ID：给java类起一个对象名字
    class：java字节码文件的位置
    <jsp:useBean   id="c" scope="page" class="com.yangtao.Calculate"></jsp:useBean>
    <jsp:useBean   id="d" scope="page" class="com.yangtao.Opertate"></jsp:useBean>
    <%
    String path = request.getContextPath();
    String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
    
    //验证表单
    如果request对象的获取的action参数的值是"Do",则对起处理
    if("Do".equals(request.getParameter("action"))){
    
    //获取参数
    String firstString=request.getParameter("firstNumber");
    String secondString=request.getParameter("secondNumber");
    String operString=request.getParameter("radio");
    
    //复制给Bean
    
    c.setFirstNumber(Double.parseDouble( firstString));
    c.setOprateCharechter(Integer.parseInt( operString));
    c.setSecondNumber(Double.parseDouble(secondString));
    //计算结果
    
    double resultData=d.doCalculator(c);
    
    out.print("计算结果是:\t"+resultData);
    }

3.java代码对计算逻辑的实现

package com.yangtao; /** * 这是计算机实体类 * @author yangtao * */ public class Calculate { /** * firstNumber 这个是第一个计算参数 */ private double firstNumber; private double secondNumber; private int oprateCharechter; /** * 第一个参数的GET方法 * @return firstNumber */ public double getFirstNumber() { return firstNumber; } public void setFirstNumber(double firstNumber) { this.firstNumber = firstNumber; } public double getSecondNumber() { return secondNumber; } public void setSecondNumber(double secondNumber) { this.secondNumber = secondNumber; } public int getOprateCharechter() { return oprateCharechter; } public void setOprateCharechter(int oprateCharechter) { this.oprateCharechter = oprateCharechter; } }

package com.yangtao; /** * 这是计算类 * @author lenovo * */ public class Opertate { /** * 这是计算机类 的变量 */ private Calculate calc; /** * 这是是计算方法 */ public double doCalculator( Calculate calc){ double first=calc.getFirstNumber(); double second=calc.getSecondNumber(); int opion = calc.getOprateCharechter(); double resulrValues=0.0; switch (opion) { case 1: resulrValues= first+second; break; case 2: resulrValues= first-second; break; case 3: resulrValues= first*second; break; case 4: resulrValues= first/second; break; default: break; } return resulrValues; } }

4.<%@ include file="MyJsp.jsp" %>

转载于:https://www.cnblogs.com/rainbowbridge/p/11517245.html