如何将HttpServletResponse传播到客户端？

Question

We're working on a new web application to replace an old one that is commonly being used by our company. They both will ultimately have the exact same API. What we'd like to do initially is test out the new functionality by having clients send requests to the new web app, but then have our new web app propagate their requests to the old web app and send the old web app's http responses back to our clients (so that from client point of view, nothing has changed).

What I'd like to do is get the exact HttpServletResponse object that we're getting back from the old web app and send that back to clients of the new web app. What is the best way of performing this? I know that once I can retrieve the HttpServletResponse, I can just set it equal to the one we have as a parameter to our functions (API handlers) in our new web app's REST controller, but I'm having trouble retrieving it.

Is there any way of retrieving the HttpServlet response via Spring's RestTemplate?

Answer 1

You can use org.apache.commons.httpclient.HttpClient

It has public int executeMethod(HttpMethod method) where you can define request and after checking status is success

you can use all the HttpMethod methods.

InputStream getResponseBodyAsStream()
Header[] getResponseHeaders();

and pass to your response. Like this

public static void main(String[] args) throws Exception {
    HttpClient client = new HttpClient();
    GetMethod method = new GetMethod("http://The old service url");
    method.addRequestHeader("X-Username", "user");
    method.addRequestHeader("X-Password", "password");
    // Execute the HTTP GET request
    int status = client.executeMethod(method);
    if(status == 200){
        InputStream in = method.getResponseBodyAsStream();
        OutputStream out=the out of your response
        IOUtils.copy(in, out);
        in.close();
        out.flush();
        out.close();
    }
}