How to get JSON from webview with dynamic URL?

Question

I need to get JSON out of server response. I use WebView.loadUrl() and get HTML page with JSON in body in response. It shows in webView, but how can I access it from the code?

UPDATE: Important notice, I have dynamic URL.

Is there a reason you need to display the page with WebView? It's easy to get JSON from a response if you just get it directly using an `HttpURLConnection`. — NoChinDeluxe, Oct 12 '15 at 14:38
I use webview because I connect to api which requests mine app's ID + I need to open one webpage from it first. — aleien, Oct 12 '15 at 14:44

score 1 · Accepted Answer · edited May 23 '17 at 10:27

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I think that you don't need a WebView for that. You have to use a HTTP Client for requesting the server.

A good one is OkHttp or you can use only Android-Stuff, check the doc.

If you realy would like to use a WebView, check this answer.

edited May 23 '17 at 10:27

Community

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answered Oct 12 '15 at 14:41

Kevin Robatel

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Thank you for the answer! I'll try that immediately. Also, can I use retrofit to get JSON? – aleien Oct 12 '15 at 14:49
Yes you can. JSON is just some text. After you should use a library for reading the JSON easily like GSON from Google, see http://stackoverflow.com/a/31743324/244702 – Kevin Robatel Oct 12 '15 at 14:53
Since I use dynamic url, it seems I can't rely on retrofit. But JavaScript method worked perfectly, thanks! – aleien Oct 12 '15 at 15:42

score 0 · Answer 2 · answered Oct 12 '15 at 14:48

You can make a request to a server and give it your APP ID via a JSONObject (or whatever it requires). I'm pretty sure you don't need a WebView to accomplish this. Here's an example of some code I used for a similar operation. Here, I stored a device ID as well as some other access credentials in a JSONObject. I then pass that to a server to request a response, I then receive a JSON response in a plain String format.

//open connection to the server
URL url = new URL("your_url");
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();

//set request properties
httpURLConnection.setDoOutput(true); //defaults request method to POST
httpURLConnection.setDoInput(true);  //allow input to this HttpURLConnection
httpURLConnection.setRequestProperty("Content-Type", "application/json"); //header params
httpURLConnection.setRequestProperty("Accept", "application/json"); //header params
httpURLConnection.setFixedLengthStreamingMode(jsonToSend.toString().getBytes().length); //header param "content-length"

//open output stream and POST our JSON data to server
OutputStreamWriter outputStreamWriter = new OutputStreamWriter(httpURLConnection.getOutputStream());
outputStreamWriter.write(jsonToSend.toString()); //whatever you're sending to the server
outputStreamWriter.flush(); //flush the stream when we're finished writing to make sure all bytes get to their destination

//prepare input buffer and get the http response from server
StringBuilder stringBuilder = new StringBuilder();
int responseCode = httpURLConnection.getResponseCode();

//Check to make sure we got a valid status response from the server,
//then get the server JSON response if we did.
if(responseCode == HttpURLConnection.HTTP_OK) {

    //read in each line of the response to the input buffer
    BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(httpURLConnection.getInputStream(),"utf-8"));
    String line;
    while ((line = bufferedReader.readLine()) != null) {
        stringBuilder.append(line).append("\n");
    }

    //You've now got the JSON, which can be accessed just as a
    //String -- stringBuilder.toString() -- or converted to a JSONObject

    bufferedReader.close(); //close out the input stream

How to get JSON from webview with dynamic URL?

2 Answers2