Passing JSON data from PHP script to Android

Question

On the PHP end, I'm getting a JSON Object that we're sending back to Android. The PHP code is straightforward and just echos the JSON object like I have seen in almost every tutorial.

This line creates an exception every other query. Am I doing something very wrong?

JSONObject json = jsonParser.makeHttpRequest(signInURL,
                    "POST", params1);

 04-15 21:40:44.787: E/AndroidRuntime(6325): java.lang.RuntimeException: An error occured while executing doInBackground()

I'm following these instructions:

How json will be used in our application.

• When android application will execute, it will connect android device to PHP Script.
• PHP Script will fetch data from the database. It will encode it into json format and send it to the device.
• Now, android application will get these encoded data. It will parse the data and display it on android device.

In our Android application,

• Use a HttpPost to get the data,
• Convert response to string
• Parse JSON data, and use it as you want

Edit: The problem was actually just PHP warnings that needed to be fixed. Thanks everyone!

Answer 1

set internet permission in AndroidManifest.xml :

<uses-permission android:name="android.permission.INTERNET"></uses-permission>   

Http request from android to server

public String httpRequest(String url, String query, int methodtype){

    try {
        String reqUrl = url + query;

        switch (methodtype) {
            case 1:
                HttpGet httpGet = new HttpGet(reqUrl);
                httpResponse = httpClient.execute(httpGet);
                break;
            case 2:
                HttpPost httpPost = new HttpPost(reqUrl);
                httpResponse = httpClient.execute(httpPost);
                break;

        }



        HttpEntity httpEntity = httpResponse.getEntity();
        instrObj = httpEntity.getContent();

    } catch (UnsupportedEncodingException e) {
        //HandleException
    } catch (ClientProtocolException e) {
        //HandleException
    } catch (IOException e) {
        //HandleException
    }

    try {
        BufferedReader reader = new BufferedReader(new InputStreamReader(instrObj, "iso-8859-1"), 8);
        StringBuilder sb = new StringBuilder();
        String line = null;
        while ((line = reader.readLine()) != null) {
            sb.append(line + "\n");
        }
        instrObj.close();
        json = sb.toString();

    } catch (Exception e) {

    }       
    return json;
}

For posting the form data to the server HttpPost is used and to retreive the data from server HttpGet is used....

Answer 2

Try this piece of code

try {
    URL Url = new URL(" --------");
    HttpURLConnection connection = (HttpURLConnection) Url.openConnection();
    connection.connect();

    int responseCode = connection.getResponseCode();
    if (responseCode == HttpURLConnection.HTTP_OK) {
        InputStream inputStream = connection.getInputStream();
        Reader reader = new InputStreamReader(inputStream);

        int contentLength = connection.getContentLength();
        char[] charArray = new char[contentLength];
        reader.read(charArray);

        JSONObject jsonResponse = new JSONObject(charArray.toString());
    }
    else {
        Log.i("", "HTTP Response Code: " + responseCode);
    }
}
catch (Exception e) {
}

Answer 3

It sometimes happens for not setting the internet permission.

To set internet permission do this:

 <uses-permission android:name="android.permission.INTERNET"></uses-permission>

Hope this helps.. :)