javaweb学习6_Httpsession接口常用的方法及HttpServletRequest接口中session方法Demo
1.HttpSession 常用方法
getId()
getCreationTime()
getLastAccessedTime()
setMaxInactiveInterval()
getMaxInactiveInterval()
isNew() 如果客户端请求消息中返回了一个与Servlet程序当前获得的HttpSession对象的会话标识号相同的会话标识号,则认为这个HttpSession对象不是新建的。
invalidate()
getServletContext()
setAttribute()
getAttribute()
removeAttribute()
getAttributeNames()
2.HttpServletRequest接口中的Session方法
getSession()
public HttpSession getSession(boolean create)
public HttpSession getSession()
isRequestedSessionIdValid()
isRequestedSessionIdFromCookie()
isRequestedSessionIdFromURL()
3. 综合Dome
总结理解 session 的方法
代码:login.jsp hello.jsp, logoff.jsp
1)login.jsp
1 <%@ page language="java" contentType="text/html; charset=UTF-8" 2 pageEncoding="UTF-8"%> 3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 4 <html> 5 <head> 6 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 7 <title>session login JSP</title> 8 </head> 9 <body> 10 11 SessionId :<%= session.getId() %> 12 <br><br> 13 14 IsNew:<%= session.isNew() %> 15 <br><br> 16 17 MaxInactiveInterval:<%= session.getMaxInactiveInterval() %> 18 <br><br> 19 20 CreateTime:<%= session.getCreationTime() %> 21 <br><br> 22 23 LastAccessTime:<%= session.getLastAccessedTime() %> 24 <br><br> 25 <% 26 Object username = session.getAttribute("username"); 27 if(username == null){ 28 username = ""; 29 } 30 %> 31 32 <form action="./hello.jsp" method="post"> 33 34 username:<input type="text" name="username" value="<%= username %>"/> 35 <input type="submit" value="submit"/> 36 </form> 37 38 </body> 39 </html>
效果图:
经过注销后的 login界面
2) hello.jsp
1 <%@ page language="java" contentType="text/html; charset=UTF-8" 2 pageEncoding="UTF-8"%> 3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 4 <html> 5 <head> 6 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 7 <title>session login JSP</title> 8 </head> 9 <body> 10 11 SessionId :<%= session.getId() %> 12 <br><br> 13 14 IsNew:<%= session.isNew() %> 15 <br><br> 16 17 MaxInactiveInterval:<%= session.getMaxInactiveInterval() %> 18 <br><br> 19 20 CreateTime:<%= session.getCreationTime() %> 21 <br><br> 22 23 LastAccessTime:<%= session.getLastAccessedTime() %> 24 <br><br> 25 26 hello : <%= request.getParameter("username") %> 27 <% 28 session.setAttribute("username", request.getParameter("username")); 29 %> 30 <br><br> 31 <a href="login.jsp">重新登录</a> 32 33 <a href="logoff.jsp">注销</a> 34 </body> 35 </html>
效果图:
logoff.jsp
1 <%@ page language="java" contentType="text/html; charset=UTF-8" 2 pageEncoding="UTF-8"%> 3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 4 <html> 5 <head> 6 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 7 <title>logoff JSP</title> 8 </head> 9 <body> 10 11 SessionId :<%= session.getId() %> 12 <br><br> 13 14 IsNew:<%= session.isNew() %> 15 <br><br> 16 17 MaxInactiveInterval:<%= session.getMaxInactiveInterval() %> 18 <br><br> 19 20 CreateTime:<%= session.getCreationTime() %> 21 <br><br> 22 23 LastAccessTime:<%= session.getLastAccessedTime() %> 24 <br><br> 25 26 Bye : <%= session.getAttribute("username") %> 27 28 <br><br> 29 30 <a href="login.jsp">重新登录</a> 31 32 <% 33 session.invalidate(); 34 %> 35 36 37 </body> 38 </html>
效果图: