Spring 限制用户重复登录

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;

import xxxxx.TSUser;

/**
*
* @author yuki_ho
*
*/
public class SessionUserListener implements HttpSessionListener{

// key为sessionId，value为HttpSession，使用static，定义静态变量，使之程序运行时，一直存在内存中。
private static Map<String, HttpSession> sessionMap = new HashMap<String, HttpSession>(500);

/**
* HttpSessionListener中的方法，在创建session
*/
@Override
public void sessionCreated(HttpSessionEvent event) {
// TODO Auto-generated method stub
}

/**
* HttpSessionListener中的方法，回收session时,删除sessionMap中对应的session
*/
@Override
public void sessionDestroyed(HttpSessionEvent event) {
getSessionMap().remove(event.getSession().getId());
}

/**
* 得到在线用户会话集合
*/
public static List<HttpSession> getUserSessions() {
List<HttpSession> list = new ArrayList<HttpSession>();
Iterator<String> iterator = getSessionMapKeySetIt();
while (iterator.hasNext()) {
String key = iterator.next();
HttpSession session = getSessionMap().get(key);
list.add(session);
}
return list;
}

/**
* 得到用户对应会话map，key为用户ID,value为会话ID
*/
public static Map<String, String> getUserSessionMap() {
Map<String, String> map = new HashMap<String, String>();
Iterator<String> iter = getSessionMapKeySetIt();
while (iter.hasNext()) {
String sessionId = iter.next();
HttpSession session = getSessionMap().get(sessionId);
TSUser user = (TSUser) session.getAttribute("LOCAL_CLINET_USER");
if (user != null) {
map.put(user.getId(), sessionId);
}
}
return map;
}

/**
* 移除用户Session
*/
public synchronized static void removeUserSession(String userId) {
Map<String, String> userSessionMap = getUserSessionMap();
if (userSessionMap.containsKey(userId)) {
String sessionId = userSessionMap.get(userId);
getSessionMap().get(sessionId).invalidate();
getSessionMap().remove(sessionId);
}
}

/**
* 增加用户到session集合中
*/
public static void addUserSession(HttpSession session) {
getSessionMap().put(session.getId(), session);
}

/**
* 移除一个session
*/
public static void removeSession(String sessionID) {
getSessionMap().remove(sessionID);
}

public static boolean containsKey(String key) {
return getSessionMap().containsKey(key);
}

/**
* 判断该用户是否已重复登录，使用
* 同步方法，只允许一个线程进入，才好验证是否重复登录
* @param user
* @return
*/
public synchronized static boolean checkIfHasLogin(TSUser user) {
Iterator<String> iter = getSessionMapKeySetIt();
while (iter.hasNext()) {
String sessionId = iter.next();
HttpSession session = getSessionMap().get(sessionId);
TSUser sessionuser = (TSUser) session.getAttribute("LOCAL_CLINET_USER");  // 这是你设置 保存用户对应session名
if (sessionuser != null) {
if (sessionuser.getId().equals(user.getId())){
return true;
}
}
}
return false;
}

/**
* 获取在线的sessionMap
*/
public static Map<String, HttpSession> getSessionMap() {
return sessionMap;
}

/**
* 获取在线sessionMap中的SessionId
*/
public static Iterator<String> getSessionMapKeySetIt() {
return getSessionMap().keySet().iterator();
}

}

<listener>
<listener-class>xxxxx.listener.SessionUserListener</listener-class>
</listener>

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

public class ContextHolderUtils {
/**
* SpringMvc下获取request
*
* @return
*/
public static HttpServletRequest getRequest() {
HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
return request;

}
/**
* SpringMvc下获取session
*
* @return
*/
public static HttpSession getSession() {
HttpSession session = getRequest().getSession();
return session;

}

}

import java.util.Map;

import javax.servlet.http.HttpSession;

import xxxxx.ContextHolderUtils;
import xxxxx.TSUser;
import org.springframework.stereotype.Service;

import xxxxx.listener.SessionUserListener;
import xxxxx.listener.service.SessionUserI;

/**
*
* @author yuki_ho
*
*/
@Service("sessionUser")
public class SessionUserImpl implements SessionUserI{

/**
* 登录时使用 --  检查是否重复登录并把在线的 替换成 自己
*/
@Override
public void changeLogin4Me(TSUser tsUser) {
Boolean hasLogin = SessionUserListener.checkIfHasLogin(tsUser);
HttpSession session = ContextHolderUtils.getSession();
if(hasLogin)
SessionUserListener.removeUserSession(tsUser.getId());
SessionUserListener.addUserSession(session);
}

/**
* 使用 拦截器时 -- 检查是否当前 session用户
*/
@Override
public Boolean checkLoginIsMe(TSUser tsUser) {
if(null==tsUser)
return false;
Map<String,String> SessionUser=	SessionUserListener.getUserSessionMap();
String curSession=SessionUser.get(tsUser.getId());
HttpSession session = ContextHolderUtils.getSession();
if(curSession.equals(session.getId()))
return true;
return false;
}

}

Boolean flag	 =sessionUser.checkLoginIsMe(tsuer);
if(!flag)	{
session.removeAttribute("LOCAL_CLINET_USER");
response.sendRedirect("loginController.do?login");
return false;
}