如何从过滤器重定向到另一台主机？

Question

如何将请求从过滤器转发到另一个 URL 并返回结果？

我正在使用Filter 和HttpClient.execute() 方法来转发请求。这样的方式对吗？

代码如下：

public void doFilter(ServletRequest req, ServletResponse response, FilterChain chain)
...
HttpRequestBase method = null;
URI uri = null;
if (isPost) {
    method = new HttpPost();
} else {
    method = new HttpGet();
}

uri = new URI(newUrl);    

Enumeration<String> headerNames = request.getHeaderNames();

 while (headerNames.hasMoreElements()) {
    String header = headerNames.nextElement();    
    method.setHeader(header, request.getHeader(header));    
}
method.setURI(uri);

HttpResponse downstreamResponse = httpClient.execute(method);

ByteArrayOutputStream baos = new ByteArrayOutputStream(2048);
downstreamResponse.getEntity().writeTo(baos);
OutputStream responseStream = response.getOutputStream();
responseStream.write(responseBytes);

Answer 1

在你的

doFilter(ServletRequest req, ServletResponse res,
            FilterChain chain) 

你会收到ServletResponse

所以您可以将其转换为 HttpServletResponse

HttpServletResponse httpResponse = (HttpServletResponse) res;
httpResponse.sendRedirect("/login.jsp");