我的代码显示不出用户信息 大神看看那里错了
import java.util.ArrayList;
import javax.servlet.annotation.WebListener;
import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;
import Entity.User;
import SessionUtil.SessionUtil;
@WebListener
public class MyHttpSession implements HttpSessionListener {
private int number = 0;
@Override
public void sessionCreated(HttpSessionEvent arg0) {
number++;
arg0.getSession().getServletContext().setAttribute("Number", number);
}
@Override
public void sessionDestroyed(HttpSessionEvent arg0) {
number--;
arg0.getSession().getServletContext().setAttribute("Number", number);
ArrayList<User> userlist = null;//在线用户List
userlist = (ArrayList<User>) arg0.getSession().getServletContext()
.getAttribute("userlist");
String sessionid = arg0.getSession().getId();
if (SessionUtil.getUserBySessionId(userlist,sessionid)!=null) {
userlist.remove(SessionUtil.getUserBySessionId(userlist, sessionid));
System.out.println("删除的sessionId为："+sessionid);
}
}
}public class MyServletRequest implements ServletRequestListener {
private ArrayList<User> userlist;
@Override
public void requestDestroyed(ServletRequestEvent arg0) {
}
public void requestInitialized(ServletRequestEvent arg0) {
//不是第一次登录就可以从上下文中获取userlist
userlist = (ArrayList<User>)arg0.getServletContext().getAttribute("userlist");
//第一次登录
if(userlist==null){
userlist = new ArrayList<User>();
}
HttpServletRequest request = (HttpServletRequest) arg0.getServletRequest();
//得到session id
String sessionIdString = request.getSession().getId();
//如果userlist有改id 则不加入userlist 没有则创建一个user 加入userlist中
if(SessionUtil.getUserBySessionId(userlist,sessionIdString)==null){
User user = new User();
user.setSessionIdString(sessionIdString);
user.setSessionTime(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()));
user.setUserurl(request.getRemoteAddr());
userlist.add(user);
System.out.println("加入的用户sessionId为："+sessionIdString);
}
//添加userList到application（ServletContext的对象
arg0.getServletContext().setAttribute("userlist",userlist);
}
}jsp页面：
<body>
当前在线用户人数:${Number }<br/>
<%
ArrayList<Entity.User> userlist = (ArrayList<Entity.User>)request.getServletContext().getAttribute("userlist");
if(userlist!=null){
for(int i = 0 ; i < userlist.size() ; i++){
Entity.User user = userlist.get(i);
%>
IP:<%=user.getSessionIdString() %>,FirstTime:<%=user.getSessionTime() %>,SessionId:<%=user.getUserurl() %> <br/>
<%}
}
else{
out.println("无用户");
}%>
</body>public class SessionUtil {
public static Object getUserBySessionId(ArrayList<User> userList, String sessionIdString) {
for (int i = 0; i < userList.size(); i++) {
User user = userList.get(i);
if (user.getSessionIdString().equals(sessionIdString)) {
return user;
}
}
return null;
}
}
