Servlet does not receive the post parameters after Redirect (Response code 302)

Question

I want to access my web site that first requires a basic authorization, and then post the parameters (search keyword) to my home page.

My code can pass the basic authorization and will get the response text, however I cannot get the search result but get the home page code instead.

As such, I printed the parameters.size() and it return 0, so I doubt the HttpClient redirect method does not pass the parameters after basic authorization.

Following my code, which is trying to get the search result:

List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("search_keyword", "test"));
params.add(new BasicNameValuePair("search_size", "50"));

DefaultHttpClient httpclient = new DefaultHttpClient();
httpclient.setRedirectStrategy(new DefaultRedirectStrategy() {                
    public boolean isRedirected(HttpRequest request, HttpResponse response, HttpContext context) throws ProtocolException  {
        boolean isRedirect=false;
        try {
            isRedirect = super.isRedirected(request, response, context);
        } catch (ProtocolException e) {
            throw e;
        }
        if (!isRedirect) {
            int responseCode = response.getStatusLine().getStatusCode();
            if (responseCode == 301 || responseCode == 302) {
                return true;
            }
        }
        return isRedirect;
    }
});

String encoding = Base64Encoder.encode("admin:password");   
HttpPost httppost = new HttpPost("http://127.0.0.1/MySystem/home");
httppost.setHeader("Authorization", "Basic " + encoding);   
httppost.setEntity(new UrlEncodedFormEntity(params, "UTF-8"));

//Execute and get the response.
HttpResponse response = httpclient.execute(httppost);
int responseCode = response.getStatusLine().getStatusCode();

switch(responseCode) {
    case HttpURLConnection.HTTP_OK:
        HttpEntity entity = response.getEntity();
        List<NameValuePair> parameters = new ArrayList<NameValuePair>(URLEncodedUtils.parse(entity));
        System.out.println("parameters size: "+parameters.size());
        for(NameValuePair p:parameters)
            System.out.println("parameter: "+ p.getName() + p.getValue());
        if(entity != null) {
            responseText = EntityUtils.toString(entity);
            System.out.println("responseText: ");
            System.out.println(responseText);
        }
        break;
    default:
        throw new Exception("Failed to pass the basic authorization. Response code: "+responseCode);
}

Updated:

The following condition will return true:

if (responseCode == 301 || responseCode == 302) {
   return true;
}

Answer 1

Ok, I found a workaround. Basically, although 302 will redirect me to another page, the basic authorization session is passed in the current httpclient .

The solution is to reuse the httpclient under the case HttpURLConnection.HTTP_OK: and also close the entity bufferreader in order to prevent the "connection still allocated" Exception.

Here is the sample code:

String line;
BufferedReader br = new BufferedReader(new InputStreamReader(entity.getContent()));
StringBuilder sb = new StringBuilder();
while ((line = br.readLine()) != null) {
    sb.append(line);
}

br.close();
responseText = sb.toString();
....

HttpPost httppost2 = new HttpPost("http://127.0.0.1/MySystem/home");
httppost2.setHeader("Authorization", "Basic " + encoding);
httppost2.setEntity(new UrlEncodedFormEntity(params, "UTF-8"));
HttpResponse response2 = httpclient.execute(httppost2);
HttpEntity entity2 = response2.getEntity();