根据HttpServletRequest获取IP地址

public String getRemoteHost(javax.servlet.http.HttpServletRequest request){
    String ip = request.getHeader("x-forwarded-for");
    if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)){
        ip = request.getHeader("Proxy-Client-IP");
    }
    if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)){
        ip = request.getHeader("WL-Proxy-Client-IP");
    }
    if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)){
        ip = request.getRemoteAddr();
    }
    return ip.equals("0:0:0:0:0:0:0:1")?"127.0.0.1":ip;
}