java获得真实IP代码

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：

 1 public final class HTTPUtils {
 2 
 3     private static final String HEADER_X_FORWARDED_FOR =
 4         "X-FORWARDED-FOR";
 5 
 6     public static String remoteAddr(HttpServletRequest request) {
 7         String remoteAddr = request.getRemoteAddr();
 8         String x;
 9         if ((x = request.getHeader(HEADER_X_FORWARDED_FOR)) != null) {
10             remoteAddr = x;
11             int idx = remoteAddr.indexOf(',');
12             if (idx > -1) {
13                 remoteAddr = remoteAddr.substring(0, idx);
14             }
15         }
16         return remoteAddr;
17     }
18 
19 }

 1 public final class HTTPUtils {
 2 
 3     private static final String HEADER_X_FORWARDED_FOR =
 4         "X-FORWARDED-FOR";
 5 
 6     public static String remoteAddr(HttpServletRequest request) {
 7         String remoteAddr = request.getRemoteAddr();
 8         String x;
 9         if ((x = request.getHeader(HEADER_X_FORWARDED_FOR)) != null) {
10             remoteAddr = x;
11             int idx = remoteAddr.indexOf(',');
12             if (idx > -1) {
13                 remoteAddr = remoteAddr.substring(0, idx);
14             }
15         }
16         return remoteAddr;
17     }
18 
19 }