java web项目获取nginx反向代理后的客户端的真实ip

在ngxin代理的配置文件的location块中添加如下配置

            proxy_set_header Host $host;
	    proxy_set_header X-Real-IP $remote_addr;
	    proxy_set_header REMOTE-HOST $remote_addr;
	    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

整体如下

 location / {
	    proxy_pass http://127.0.0.1:8080;
        proxy_set_header Host $host;
	    proxy_set_header X-Real-IP $remote_addr;
	    proxy_set_header REMOTE-HOST $remote_addr;
	    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        root   html;
        index  index.html index.htm;
}

java获取真实地址的方法如下

    private static final String UNKNOWN = "unknown";
    private static final String LOCALHOST = "127.0.0.1";
    private static final String SEPARATOR = ",";

    public String getIpAddr(HttpServletRequest request) {
        String ipAddress;
        try {
            ipAddress = request.getHeader("x-forwarded-for");
            if (ipAddress == null || ipAddress.length() == 0 || UNKNOWN.equalsIgnoreCase(ipAddress)) {
                ipAddress = request.getHeader("Proxy-Client-IP");
            }
            if (ipAddress == null || ipAddress.length() == 0 || UNKNOWN.equalsIgnoreCase(ipAddress)) {
                ipAddress = request.getHeader("WL-Proxy-Client-IP");
            }
            if (ipAddress == null || ipAddress.length() == 0 || UNKNOWN.equalsIgnoreCase(ipAddress)) {
                ipAddress = request.getRemoteAddr();
                if (LOCALHOST.equals(ipAddress)) {
                    InetAddress inet = null;
                    try {
                        inet = InetAddress.getLocalHost();
                    } catch (UnknownHostException e) {
                        e.printStackTrace();
                    }
                    ipAddress = inet.getHostAddress();
                }
            }
            // 对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
            // "***.***.***.***".length()
            if (ipAddress != null && ipAddress.length() > 15) {
                if (ipAddress.indexOf(SEPARATOR) > 0) {
                    ipAddress = ipAddress.substring(0, ipAddress.indexOf(","));
                }
            }
        } catch (Exception e) {
            ipAddress = "";
        }
        return ipAddress;
    }