java如何从服务器端更改HttpServletRequest中的IP？

Question

很多人问如何从客户端更改de-IP，但我需要从服务器端进行更改（如果可能的话）

问题是我从HttpServletRequest获取IP。getRemoteAddr（），但是现在我们在IHS之前使用了代理，这个IP总是与代理IP一起提供，而不是真正的客户端IP

代理在请求中的新特定头中提供真实IP

好的，我知道这听起来很简单，我只改变获取IP的方式，并从代理提供的特定头获取IP。这是一个很好的解决方案，问题是我们必须更改很多类，我在考虑另一种可能的方式，例如，在基类的请求中，将这个IP与真实IP更改一次，然后每个人（扩展基类的人）都能正确地更新IP

那么，我能不能这样做

Answer 1

您需要添加一个过滤器来创建HttpServletRequestWrapper。调整部署描述符

各部分：

• ProxyFilter
• ProxyRequestWrapper
• 网络。xml
• ServletBehindProxy

代理过滤器：

package testingThings.wrapperAndFilter;

import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet Filter implementation class ProxyFilter
 */
public class ProxyFilter implements Filter {

    /**
     * Default constructor. 
     */
    public ProxyFilter() {
        // TODO Auto-generated constructor stub
    }

    /**
     * @see Filter#destroy()
     */
    public void destroy() {
        // TODO Auto-generated method stub
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        // delegate to the Http related doFilter method
        doFilter((HttpServletRequest)request, (HttpServletResponse)response, chain);        
    }

    public void doFilter(HttpServletRequest request, HttpServletResponse response, FilterChain chain) throws IOException, ServletException {
        // create a wrapper
        ProxyRequestWrapper replacementRequest = new ProxyRequestWrapper(request);

        // pass the request along the filter chain
        chain.doFilter(replacementRequest, response);
    }

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        // TODO Auto-generated method stub

    }
}

ProxyRequestWrapper:

package testingThings.wrapperAndFilter;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;

public class ProxyRequestWrapper extends HttpServletRequestWrapper {

    public ProxyRequestWrapper(HttpServletRequest request) {
        super(request);
    }

    @Override
    public String getRemoteAddr() {
        return getHeader("REAL-IP");
    }
}

网络。xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0">
  <filter>
    <filter-name>ProxyFilter</filter-name>
    <filter-class>testingThings.wrapperAndFilter.ProxyFilter</filter-class>
  </filter>
  <filter-mapping>
    <filter-name>ProxyFilter</filter-name>
    <url-pattern>/ServletBehindProxy</url-pattern>
  </filter-mapping>
</web-app>

ServletBehindProxy:

package testingThings.wrapperAndFilter;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class ServletBehindProxy
 */
@WebServlet("/ServletBehindProxy")
public class ServletBehindProxy extends HttpServlet {
    private static final long serialVersionUID = 1L;

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // show ip
        resp.getWriter().append(req.getRemoteAddr());
    }

}

要测试它，可以使用ModifyHeaders浏览器插件：