获取用户ID

1. public String getIpAddr(HttpServletRequest request) { 
2.        String ip = request.getHeader("x-forwarded-for"); 
3.        if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) { 
4.            ip = request.getHeader("Proxy-Client-IP"); 
5.        } 
6.        if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) { 
7.            ip = request.getHeader("WL-Proxy-Client-IP"); 
8.        } 
9.        if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) { 
10.            ip = request.getRemoteAddr(); 
11.        } 
12.        return ip; 
13.    }