java获得真实IP代码，javaip代码,在有代理服务器的情况下，

java获得真实IP代码，javaip代码,在有代理服务器的情况下，

在有代理服务器的情况下，需要通过X-FORWARDED-FOR http头来获得真实的用户ip：

public final class HTTPUtils {    private static final String HEADER_X_FORWARDED_FOR =        "X-FORWARDED-FOR";    public static String remoteAddr(HttpServletRequest request) {        String remoteAddr = request.getRemoteAddr();        String x;        if ((x = request.getHeader(HEADER_X_FORWARDED_FOR)) != null) {            remoteAddr = x;            int idx = remoteAddr.indexOf(',');            if (idx > -1) {                remoteAddr = remoteAddr.substring(0, idx);            }        }        return remoteAddr;    }}