获取Web请求客户端的IP，

RestfulWsHelper.java

public abstract class RestfulWsHelper {

	 private final static String HEADER_NAME_REMOTE_IP = RestfulWsHelper.class.getSimpleName() + ".__REMOTE_CLIENT_ID__";
	
	 public final static String UNKNOW_CLIENT_IP = "UNKNOWN";
	 final static String[] SEARCHING_HEADERS = new String[] {
																"x-forwarded-for",
																"Proxy-Client-IP",
																"WL-Proxy-Client-IP"
														};
	
	 final static  String[] DEFAULT_HOST_IPS = new String[] {"127.0.0.1", "0:0:0:0:0:0:0:1"}; 

	 
	 /**
	 * @param request
	 */
	public static Headers<String> getAdditionalHeaders(HttpServletRequest request) {
		 
		Headers<String> additionals = new Headers<String>();
		additionals.add(HEADER_NAME_REMOTE_IP, getRemoteClientIpAddressFromRequest(request));
		return additionals;
	}
	
	/**
	 * @param request
	 * @return
	 */
	public static String getRemoteHostIp(HttpRequest request) {
		
		return getFirstHeaderValue(request, HEADER_NAME_REMOTE_IP );
	}
	
	/**
	 * @param request
	 * @param headerName
	 * @return
	 */
	private static String getFirstHeaderValue(HttpRequest request, String headerName) {
		
		String value = null;
		if(request.getHttpHeaders() !=null) {
			List<String> hs = request.getHttpHeaders().getRequestHeader(HEADER_NAME_REMOTE_IP);
			if(hs !=null && !hs.isEmpty()) {
				value = hs.iterator().next();
			}
		}
		return value ;
	}
	 
	/**
	 * @param request
	 * @return
	 */
	public static String getRemoteClientIpAddressFromRequest(HttpServletRequest request) {
		
		if(request == null) {
			return UNKNOW_CLIENT_IP;
		}
		
		
		String ipAddress = null; 
		for (String sh : SEARCHING_HEADERS) {
			if(isNotEmpty(request.getHeader(sh))) {
				ipAddress = sh;
				break;
			}
		}
		
		if(!isNotEmpty(ipAddress)) {
			ipAddress = request.getRemoteAddr();
			for (String hip : DEFAULT_HOST_IPS) {
				if(ipAddress.equals(hip)) { //It's from local machine.
					try {
						ipAddress = InetAddress.getLocalHost().getHostAddress();
					} catch (UnknownHostException e) { 
						//Ignore!
					}
					break;
				}
			} 
		}
		
		//Return ipAddress.
		if(ipAddress ==null) { 
			ipAddress =  UNKNOW_CLIENT_IP;
		}else if(ipAddress!=null){
			if(ipAddress.length()>15 && ipAddress.indexOf(",")>0){ //If there're multiple proxy servers.
				ipAddress = ipAddress.substring(0,ipAddress.indexOf(","));
			}
		} 
		return ipAddress;
	}
	
	
	/**
	 * @param input
	 * @return
	 */
	private static boolean isNotEmpty(String input) {
		return input!=null && input.trim().length()>0;
	}
}