Java servlet：如何在重定向时删除头“referer”？

Question

response.setHeader("Referer", null);
response.sendRedirect(url)

import java.io.IOException;
import java.util.Map;
import java.util.TreeMap;
import java.util.Map.Entry;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;

import org.springframework.stereotype.Component;
import org.springframework.web.filter.OncePerRequestFilter;

@Component
public class HeaderFilter extends OncePerRequestFilter {

@Override
protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
        throws ServletException, IOException {
    filterChain.doFilter(new HeaderHttpRequestWrapper(request), new HeaderHttpResponsetWrapper(response));

}

private static class HeaderHttpRequestWrapper extends HttpServletRequestWrapper {

    public HeaderHttpRequestWrapper(HttpServletRequest request) {
        super(request);

    }

    @Override
    public String getHeader(String name) {
        if ("Referer".equalsIgnoreCase(name))
            return "";
        return super.getHeader(name);
    }

}

private static class HeaderHttpResponsetWrapper extends HttpServletResponseWrapper {

    public HeaderHttpResponsetWrapper(HttpServletResponse response) {
        super(response);

    }

    @Override
    public void sendRedirect(String location) throws IOException {
        // TODO Auto-generated method stub
        super.sendRedirect(location);
    }

    @Override
    public void addHeader(String name, String value) {
        if ("Referer".equalsIgnoreCase(name))
            return;
        super.addHeader(name, value);
    }

    @Override
    public void setHeader(String name, String value) {
        if ("Referer".equalsIgnoreCase(name))
            return;
        super.setHeader(name, value);
    }

}

Answer 1

在响应上根本没有设置referer标头。它是在请求上设定的。通过重定向，您基本上是在指示客户机自己创建一个全新的请求。该请求是在客户端创建的，而不是在服务器端创建的。

真正的技术问题是，您根本无法从服务器端更改请求头。然而，响应标头在服务器端肯定是可以修改的，因为实际上是服务器本身创建它们。

您最接近的选择是重定向到一个代理，它碰巧是您自己的或者您完全控制的代理，然后让代理剥离请求头。或者，只让servlet本身充当代理。