session的典型案例一:使用session实现购物车

小咪咪 2022-06-06 23:42 227阅读 0赞

使用session实现购物车

step1.jsp:

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
    <%
    String path = request.getContextPath();
    String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
    %>
    
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
    <html>
      <head>
        <base href="<%=basePath%>">
        
        <title>商品列表</title>
        
    
    
      </head>
      
      <body>
        <h4>商品列表</h4>
        <form action="<%=basePath%>servlet/step2" method="post">
           <table border="1px">
             <tr>
               <td>商品名称</td>
               <td>选择</td>
             </tr>
             <tr>
               <td>java</td>
               <td><input type="checkbox" name="book" value="java"></td>
             </tr>
                      <tr>
               <td>c</td>
               <td><input type="checkbox" name="book" value="c"></td>
             </tr>
                      <tr>
               <td>c++</td>
               <td><input type="checkbox" name="book" value="c++"></td>
             </tr>
            
           </table>
           <input type="submit" value="确认">
        </form>
      </body>
    </html>

step2.java:

package com.sa.shopping;
    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;
    import javax.servlet.http.HttpSession;
    
    
    public class step2 extends HttpServlet {
    
    
    	public void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException{
              //1.获取选中的商品信息
    		String[] books=request.getParameterValues("book");
    		  //2.将商品放入session
    		HttpSession session=request.getSession();
    		session.setAttribute("book", books);
    		//3.重定向到step2
    		String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+request.getContextPath()+"/";
    		response.sendRedirect(basePath+"/shopping/step2.jsp");
    	}
    
    }

step2.jsp:

step3.java:

package com.sa.shopping;
    
    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;
    import javax.servlet.http.HttpSession;
    
    public class step3 extends HttpServlet {
    
    
    	public void doPost(HttpServletRequest request, HttpServletResponse response)
    			throws ServletException, IOException {
    
                 String receiver=request.getParameter("receiver");
                 String addr=request.getParameter("addr");
                 HttpSession session=request.getSession();
                 session.setAttribute("receiver", receiver);
                 session.setAttribute("addr", addr);
         		String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+request.getContextPath()+"/";
        		response.sendRedirect(basePath+"/shopping/step3.jsp");
    	}
    
    }

step3.jsp:

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
    <%
    String path = request.getContextPath();
    String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
    %>
    
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
    <html>
      <head>
        <base href="<%=basePath%>">
        
        <title>My JSP 'step1.jsp' starting page</title>
        
    
      </head>
      
      <body>
        <h4>信息总览</h4>
        <form action="<%=basePath%>servlet/pay" method="post">
          <%String[] books=(String[])session.getAttribute("book"); %>
            商品:<%=Arrays.asList(books) %><br>
       收件人:<%=session.getAttribute("receiver") %><br>
       地址:<%=session.getAttribute("addr") %><br>
           <input type="submit" value="付款">
        </form>
      </body>
    </html>

测试:

![Center][]

![Center 1][]

![Center 2][]

[Center]: /images/20220607/fdd5064988f2483891b4cf1a058739b2.png
[Center 1]: /images/20220607/89d411a991d64596b0b96775a1a2f1f2.png
[Center 2]: /images/20220607/05843d9ee05c43a3b1e0679177398813.png