从http协议中获得客户端ip

import javax.servlet.http.HttpServletRequest;

import org.apache.log4j.Logger;

public final class InternetProtocol {

private static Logger log = Logger.getLogger(InternetProtocol.class);
/**
 * 构造函数.
 */
private InternetProtocol() {
}

/**
 * 获取客户端IP地址.<br>
 * 支持多级反向代理
 * 
 * @param request
 *            HttpServletRequest
 * @return 客户端真实IP地址
 */
public static String getRemoteAddr(final HttpServletRequest request) {
    try{
        String remoteAddr = request.getHeader("X-Forwarded-For");
        // 如果通过多级反向代理，X-Forwarded-For的值不止一个，而是一串用逗号分隔的IP值，此时取X-Forwarded-For中第一个非unknown的有效IP字符串
        if (isEffective(remoteAddr) && (remoteAddr.indexOf(",") > -1)) {
            String[] array = remoteAddr.split(",");
            for (String element : array) {
                if (isEffective(element)) {
                    remoteAddr = element;
                    break;
                }
            }
        }
        if (!isEffective(remoteAddr)) {
            remoteAddr = request.getHeader("X-Real-IP");
        }
        if (!isEffective(remoteAddr)) {
            remoteAddr = request.getRemoteAddr();
        }
        return remoteAddr;
    }catch(Exception e){
        log.error("get romote ip error,error message:"+e.getMessage());
        return "";
    }
}

/**
 * 获取客户端源端口
 * @param request
 * @return
 */
public static Long getRemotePort(final HttpServletRequest request){
    try{
        String port = request.getHeader("remote-port");
        if( StringUtil.isNotEmptyString(port )) {
            try{
                return Long.parseLong(port);
            }catch(NumberFormatException ex){
                log.error("convert port to long error , port:    "+port);
                return 0l;
            }
        }else{
            return 0l;
        }        
    }catch(Exception e){
        log.error("get romote port error,error message:"+e.getMessage());
        return 0l;
    }
}

/**
 * 远程地址是否有效.
 * 
 * @param remoteAddr
 *            远程地址
 * @return true代表远程地址有效，false代表远程地址无效
 */
private static boolean isEffective(final String remoteAddr) {
    boolean isEffective = false;
    if ((null != remoteAddr) && (!"".equals(remoteAddr.trim()))
            && (!"unknown".equalsIgnoreCase(remoteAddr.trim()))) {
        isEffective = true;
    }
    return isEffective;
}

}

本地测试localhost会出现0:0:0:0:0:0:0:1