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post – Android: Get response from a https url

Posted by: admin June 15, 2020 Leave a comment

Questions:

Greetings,

I’m developing an Android app and need to open a url (with POST parameters) over https and get the response.

There’s the added complication that I have a self-signed certificate. I also need to accept cookies.

Anyone have any ideas about where to get started?

Many thanks in advance,

How to&Answers:

Android comes with the apache commons http library included.
Setting up a https post request is quite easy:

HttpPost post = new HttpPost("https://yourdomain.com/yourskript.xyz");
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
nameValuePairs.add(new BasicNameValuePair("postValue1", "my Value"));
nameValuePairs.add(new BasicNameValuePair("postValue2", "2nd Value"));
post.setEntity(new UrlEncodedFormEntity(nameValuePairs));

HttpClient client = new DefaultHttpClient();
HttpResponse response = client.execute(post);
HttpEntity entity = response.getEntity();

String responseText = EntityUtils.toString(entity);

Android uses a version 4.x of the commons http library as all versions below 4.0 are out of their lifecycle.

I can’t tell exactly how to register a self-signed certificate to the HttpClient, but mybe the commons http documentation helps:

http://hc.apache.org/httpcomponents-client-ga/tutorial/html/connmgmt.html#d4e506

Answer:

I managed to get it all working asyncronously with both cookies and unsigned https.

I used the code here:

http://masl.cis.gvsu.edu/2010/04/05/android-code-sample-asynchronous-http-connections/

and modified for unsigned https using Brian Yarger’s code here:

Self-signed SSL acceptance on Android

(Add the above code to the beginning of run() in HttpConnection.java)

To get the cookies to work, I had to modify some code (POST snippet from HttpConnection.java):

         case POST:
            HttpPost httpPost = new HttpPost(url);
            httpPost.setEntity(new StringEntity(data));
            httpPost.addHeader("Cookie", Cookie.getCookie());
            response = httpClient.execute(httpPost);

            Header[] headers=response.getAllHeaders();
            for(int i=0;i<headers.length;i++){
                if(headers[i].getName().equalsIgnoreCase("Set-Cookie")){
                    //Log.i("i",headers[i].getName()+"---"+headers[i].getValue());
                    Cookie.setCookie(headers[i].getValue());
                    break;
                }
            }
            break;

Many thanks to everyone for pointing me in the direction,