登录用户监听

package com.nbw.login;

import java.util.Date;

import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpSessionBindingEvent;
import javax.servlet.http.HttpSessionBindingListener;

import com.nbw.database.DBAccess;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class OnLineUsersListener implements HttpSessionBindingListener {

private String userIP;

public void valueBound(HttpSessionBindingEvent arg0) {
}

public void valueUnbound(HttpSessionBindingEvent arg0) {
HttpSession session = arg0.getSession();
String userId = arg0.getName();
       
        Connection conn = null;
Statement stmt = null;
ResultSet rs = null;
Statement stmt2 = null;
try {
conn = DBAccess.getConnection();
stmt = conn.createStatement();
            String sql = "select t.userid from sys_user t where t.userid = '"+userId+"'";
            rs = stmt.executeQuery(sql);
            if(rs.next()){
                String userid = rs.getString(1);
                if(null != userid && !"".equals(userid)){
                    stmt2 = conn.createStatement();
                    String sql2 = "update sys_user t set t.STATE = '0',t.last_log_ip = null, t.STATE_CHANGE_TIME = sysdate where t.userid = '"+userid+"'";
                    stmt2.execute(sql2);
                    stmt2.close();
                }
            }
            rs.close();
            stmt.close();
            conn.close();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (stmt2 != null) {
stmt2.close();
}
if (rs != null) {
rs.close();
}
if (stmt != null) {
stmt.close();
}
if (conn != null) {
conn.close();
}
} catch (SQLException e) {
System.out.println("error" + e.getMessage());
}
}
}

public void setUserIP(String userIP) {
this.userIP = userIP;
}

public String getUserIP() {
return userIP;
}
}


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  OnLineUsersListener onLineUsersListener = new OnLineUsersListener();
            onLineUsersListener.setUserIP(remoteIP);
            this.getRequest().getSession().setAttribute((String)userHash.get("userid"), onLineUsersListener);