session常用方法示例

女爷i 2022-06-06 23:28 192阅读 0赞

功能描述：login.jsp  输入name登录，进入main.jsp，在main.jsp可以重新登陆,也可以注销当前用户。

<%@ 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 'login.jsp' starting page</title>
    
      </head>
      
      <body>
        SessionId:<%=session.getId() %><br><br>
        IsNew:<%=session.isNew() %><br><br>
        MaxInactiveInterval:<%=session.getMaxInactiveInterval() %><br><br>
        CreationTime:<%=session.getCreationTime() %><br><br>
        LastAccessedTime:<%=session.getLastAccessedTime() %><br><br>
        <form action="<%=basePath%>session/main.jsp">
        username:<input type="text" name="username" 
           <% Object obj=session.getAttribute("username");
             if(obj==null){
            	 obj="";
             }%>
                        value=<%=obj.toString()%>>
        <input type="submit" value="提交">
        </form>
      </body>
    </html>

main.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 'main.jsp' starting page</title>
    
      </head>
      
      <body>
        SessionId:<%=session.getId() %><br><br>
        IsNew:<%=session.isNew() %><br><br>
        MaxInactiveInterval:<%=session.getMaxInactiveInterval() %><br><br>
        CreationTime:<%=session.getCreationTime() %><br><br>
        LastAccessedTime:<%=session.getLastAccessedTime() %><br><br>
     
          用户名:<%=request.getParameter("username") %><br>
       <a href="<%=basePath%>session/login.jsp?username=<%session.setAttribute("username",request.getParameter("username"));%>">返回登录页</a><br>
        <a href="<%=basePath%>session/logout.jsp?username=<%session.setAttribute("username",request.getParameter("username"));%>">注销</a><br>
       
      </body>
    </html>

logout.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 'login.jsp' starting page</title>
    
      </head>
      
      <body>
        SessionId:<%=session.getId() %><br><br>
        IsNew:<%=session.isNew() %><br><br>
        MaxInactiveInterval:<%=session.getMaxInactiveInterval() %><br><br>
        CreationTime:<%=session.getCreationTime() %><br><br>
        LastAccessedTime:<%=session.getLastAccessedTime() %><br><br>
        <form action="<%=basePath%>session/main.jsp">
        bye:<input type="text" name="username" 
           <% Object obj=session.getAttribute("username");
             if(obj==null){
            	 obj="";
             }%>
                        value=<%=obj.toString()%>>
        <a href="<%=basePath%>session/login.jsp">返回登录页</a><br>
        <%session.invalidate(); %>
        </form>
      </body>
    </html>

测试：

进入login.jsp,并输入内容:

![Center][]

点击提交，进入main.jsp:

![Center 1][]

点击main.jsp中的"返回登录页"按钮：

![Center 2][]

点击main.jsp中的"注销"按钮：

![Center 3][]

点击logout.jsp中的“返回登录页”按钮：

![Center 4][]

[Center]: /images/20220607/45963f12394841ae8581e62e65690761.png
[Center 1]: /images/20220607/5492ba02ee2048fa81c6de2d928dda4f.png
[Center 2]: /images/20220607/d8a5d433fa5844049ebfa4524111bcf4.png
[Center 3]: /images/20220607/dc98033112384d858bd0dbda1a875f31.png
[Center 4]: /images/20220607/e90a4ccf460d4b969b0b6570bb69fce3.png