用Java来获取访问者真实的IP地址

叁歲伎倆 2022-05-27 07:48 181阅读 0赞

# 主要说明 #

在JSP里，获取客户端的IP地址的方法是：request.getRemoteAddr()，这种方法在大部分情况下都是有效的。但是在通过了Apache,Squid等反向代理软件就不能获取到客户端的真实IP地址了。如果使用了反向代理软件，用request.getRemoteAddr()方法获取的IP地址是：127.0.0.1或192.168.1.110，而并不是客户端的真实ＩＰ。

经过代理以后，由于在客户端和服务之间增加了中间层，因此服务器无法直接拿到客户端的 IP，服务器端应用也无法直接通过转发请求的地址返回给客户端。但是在转发请求的HTTP头信息中，增加了X－FORWARDED－FOR信息。用以跟踪原有的客户端IP地址和原来客户端请求的服务器地址。当我们访问index.jsp/时，其实并不是我们浏览器真正访问到了服务器上的index.jsp文件，而是先由代理服务器去访问index.jsp ，代理服务器再将访问到的结果返回给我们的浏览器，因为是代理服务器去访问index.jsp的，所以index.jsp中通过request.getRemoteAddr()的方法获取的IP实际上是代理服务器的地址，并不是客户端的IP地址。

# （一）方法一　 #

于是可得出获得客户端真实IP地址的方法一：

public String getRemortIP(HttpServletRequest request) \{    
    if (request.getHeader("x-forwarded-for") == null) \{    
        return request.getRemoteAddr();    
    \}    
    return request.getHeader("x-forwarded-for");

# （二）方法二 #

获得客户端真实IP地址的方法二：  
public String getIpAddr(HttpServletRequest request) \{    
    String ip = request.getHeader("x-forwarded-for");    
    if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) \{    
        ip = request.getHeader("Proxy-Client-IP");    
    \}    
    if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) \{    
        ip = request.getHeader("WL-Proxy-Client-IP");    
    \}    
    if(ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) \{    
        ip = request.getRemoteAddr();    
    \}    
    return ip;    
\}

可是，如果通过了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP值，究竟哪个才是真正的用户端的真实IP呢？

答案是取X-Forwarded-For中第一个非unknown的有效IP字符串。如：  
X-Forwarded-For：192.168.1.110, 192.168.1.120, 192.168.1.130, 192.168.1.100

用户真实IP为： 192.168.1.110

# （三）方法三，参考网友代码 #

import javax.servlet.http.HttpServletRequest;  
      
    /** 
     * 自定义访问对象工具类 
     *  
     * 获取对象的IP地址等信息 
     * @author X-rapido 
     * 
     */  
    public class CusAccessObjectUtil {  
      
        /** 
         * 获取用户真实IP地址，不使用request.getRemoteAddr();的原因是有可能用户使用了代理软件方式避免真实IP地址, 
    *  
         * 可是，如果通过了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP值，究竟哪个才是真正的用户端的真实IP呢？ 
         * 答案是取X-Forwarded-For中第一个非unknown的有效IP字符串。 
         *  
         * 如：X-Forwarded-For：192.168.1.110, 192.168.1.120, 192.168.1.130, 
         * 192.168.1.100 
         *  
         * 用户真实IP为： 192.168.1.110 
         *  
         * @param request 
         * @return 
         */  
        public static String getIpAddress(HttpServletRequest request) {  
            String ip = request.getHeader("x-forwarded-for");  
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
                ip = request.getHeader("Proxy-Client-IP");  
            }  
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
                ip = request.getHeader("WL-Proxy-Client-IP");  
            }  
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
                ip = request.getHeader("HTTP_CLIENT_IP");  
            }  
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
                ip = request.getHeader("HTTP_X_FORWARDED_FOR");  
            }  
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
                ip = request.getRemoteAddr();  
            }  
            return ip;  
        }  
          
    }

/\*\*

\*获取端口

\*/

public void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
       String uri = request.getRequestURI();//返回请求行中的资源名称
       String url = request.getRequestURL().toString();//获得客户端发送请求的完整url
       String ip = request.getRemoteAddr();//返回发出请求的IP地址
       String params = request.getQueryString();//返回请求行中的参数部分
       String host=request.getRemoteHost();//返回发出请求的客户机的主机名
       int port =request.getRemotePort();//返回发出请求的客户机的端口号。
       System.out.println(ip);
       System.out.println(url);
       System.out.println(uri);
       System.out.println(params);
       System.out.println(host);
       System.out.println(port);
    }

# （四）网友总结的几种方法: #

/** * 获取客户端ip地址(可以穿透代理) * * @param request * @return */
        public static String getRemoteAddr(HttpServletRequest request) {
            String ip = request.getHeader("X-Forwarded-For");
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getHeader("Proxy-Client-IP");
            }
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getHeader("WL-Proxy-Client-IP");
            }
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getHeader("HTTP_CLIENT_IP");
            }
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getHeader("HTTP_X_FORWARDED_FOR");
            }
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                ip = request.getRemoteAddr();
            }
            return ip;
        }
        private static final String[] HEADERS_TO_TRY = { 
            "X-Forwarded-For",
            "Proxy-Client-IP",
            "WL-Proxy-Client-IP",
            "HTTP_X_FORWARDED_FOR",
            "HTTP_X_FORWARDED",
            "HTTP_X_CLUSTER_CLIENT_IP",
            "HTTP_CLIENT_IP",
            "HTTP_FORWARDED_FOR",
            "HTTP_FORWARDED",
            "HTTP_VIA",
            "REMOTE_ADDR",
            "X-Real-IP"};
    
        /*** * 获取客户端ip地址(可以穿透代理) * @param request * @return */
        public static String getClientIpAddress(HttpServletRequest request) {
            for (String header : HEADERS_TO_TRY) {
                String ip = request.getHeader(header);
                if (ip != null && ip.length() != 0 && !"unknown".equalsIgnoreCase(ip)) {
                    return ip;
                }
            }
            return request.getRemoteAddr();
        }
        /*** * 获取客户端ip地址(可以穿透代理) * @param request * @return */
        public static String getClientIpAddr(HttpServletRequest request) {  
            String ip = request.getHeader("X-Forwarded-For");  
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
                ip = request.getHeader("Proxy-Client-IP");  
            }  
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
                ip = request.getHeader("WL-Proxy-Client-IP");  
            }  
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
                ip = request.getHeader("HTTP_X_FORWARDED_FOR");  
            }  
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
                ip = request.getHeader("HTTP_X_FORWARDED");  
            }  
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
                ip = request.getHeader("HTTP_X_CLUSTER_CLIENT_IP");  
            }  
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
                ip = request.getHeader("HTTP_CLIENT_IP");  
            }  
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
                ip = request.getHeader("HTTP_FORWARDED_FOR");  
            }  
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
                ip = request.getHeader("HTTP_FORWARDED");  
            }  
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
                ip = request.getHeader("HTTP_VIA");  
            }  
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
                ip = request.getHeader("REMOTE_ADDR");  
            }  
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
                ip = request.getRemoteAddr();  
            }  
            return ip;  
        }
        public static String getIpAddr(HttpServletRequest request) {
            String ip = request.getHeader("X-Real-IP");
            if (null != ip && !"".equals(ip.trim())
                    && !"unknown".equalsIgnoreCase(ip)) {
                return ip;
            }
            ip = request.getHeader("X-Forwarded-For");
            if (null != ip && !"".equals(ip.trim())
                    && !"unknown".equalsIgnoreCase(ip)) {
                // get first ip from proxy ip
                int index = ip.indexOf(',');
                if (index != -1) {
                    return ip.substring(0, index);
                } else {
                    return ip;
                }
            }
            return request.getRemoteAddr();
        }

我使用的是spring MVC框架,测试的控制器代码如下:

package com.web.controller;
    
    import java.util.HashMap;
    import java.util.Map;
    
    import javax.servlet.http.HttpServletRequest;
    
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.ResponseBody;
    
    import com.common.util.SystemHWUtil;
    import com.common.util.WebServletUtil;
    import com.string.widget.util.ValueWidget;
    import com.util.JSONPUtil;
    /*** * 用于测试跨域 * @author huangweii * 2015年5月29日 */
    @Controller
    @RequestMapping("/cors")
    public class CORSController {
        @ResponseBody
        @RequestMapping(value = "/simple",produces=SystemHWUtil.RESPONSE_CONTENTTYPE_JSON_UTF)
        public String corsJsonSimple(HttpServletRequest request,String callback){
            String content;
            Map map=new HashMap();
            map.put("username", "黄威");
            map.put("age", "27");
            map.put("address", "beijing");
            content=HWJacksonUtils.getJsonP(map, callback);
            System.out.println("getIpAddr:"+WebServletUtil.getIpAddr(request));
            System.out.println("getRemoteAddr:"+WebServletUtil.getRemoteAddr(request));
            System.out.println("getClientIpAddr:"+WebServletUtil.getClientIpAddr(request));
            System.out.println("getClientIpAddress:"+WebServletUtil.getClientIpAddress(request));
            return content;
        }
    
    }