Spring 在DelegatingFilterProxy中设置HTTP标头

我有一个过滤器，我正在使用Springs delegatingFilterProxy拦截web服务的传入请求。根据是否设置了标志，我希望允许请求继续，否则我希望设置一个请求头，当端点检查该头时，它将指示是否允许请求继续。我想将代码放在过滤器中，以抽象检查标志的逻辑

我如何修改过滤器中的请求头（简单的代码示例会更好），这是可以接受的做法，还是应该从过滤器发送响应，而不是将决策下推到端点

   public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
if(somecondition)
    set request header and forward to endpoint
else 
    forward to endpoint without extra header

---

谢谢

您需要创建一个伪造请求来解决它

冒牌货请求

import java.util.ArrayList;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

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

public class FakeHeadersRequest extends HttpServletRequestWrapper {

    private Map<String, List<String>> headers = new HashMap<String, List<String>>();

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

    @Override
    public String getHeader(String name) {
        if (headers.containsKey(name)) {
            return headers.get(name).get(0);
        }

        return super.getHeader(name);
    }

    public void addHeader(String header, String value) {
        List<String> list = headers.get(header);
        if (list == null) {
            list = new ArrayList<String>();
            headers.put(header, list);
        }
        list.add(value);
    }

    public void setHeader(String header, String value) {
        List<String> list = new ArrayList<String>();
        headers.put(header, list);
        list.add(value);
    }

    @SuppressWarnings({ "rawtypes", "unchecked" })
    @Override
    public Enumeration getHeaderNames() {
        List<String> list = new ArrayList<String>();

        HttpServletRequest request = (HttpServletRequest) getRequest();
        Enumeration<String> e = request.getHeaderNames();
        while (e.hasMoreElements()) {
            list.add(e.nextElement());
        }

        list.addAll(headers.keySet());

        return Collections.enumeration(list);
    }
}

---

另外

请求属性更适合此用途

ServletRequest.get/setAttribute（）

。您有什么理由不能使用它们吗？

谢谢，这就是我需要的。奇怪的是，当我设置标题时，jersey类中只有标题名可用。这很有用，但是我需要能够访问标题内容

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;

public class FakeHeaderFilter implements Filter {
    public void init(FilterConfig filterConfig) {
    }

    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException {
        boolean condition = false;
        if (condition && request instanceof HttpServletRequest) {
            FakeHeadersRequest req = new FakeHeadersRequest(
                    (HttpServletRequest) request);
            req.setHeader("new-header", "some-value");
            chain.doFilter(req, response);
        } else {
            chain.doFilter(request, response);
        }

    }

    public void destroy() {
    }

}