Sending string data to PHP file on server: string

Question

I am attempting to send a string to a PHP file on a remote server using POST and `GET, the PHP then writes the string to a text file.

My code (below) compiles and runs without error, however when the submit button is pressed there is no action. I.e. the toast does not display and when I check the text file that is written to from my PHP file on the server, there is nothing.

Am I missing something very obvious that would cause this not to work? (note: "my_url" is there on purpose, that is not the error)

Android Code:

public class MainActivity extends AppCompatActivity {

    @Bind(R.id.tvTitle)
    TextView title;
    @Bind(R.id.etName)
    EditText name;
    @Bind(R.id.etEmail)
    EditText email;
    @Bind(R.id.etIdea)
    EditText idea;
    @Bind(R.id.btnSubmit)
    Button submit;

    String toSubmit = "";
    private static final int DEFAULT_BUFFER_SIZE = 1024 * 4;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);

        submit.setOnClickListener(new Button.OnClickListener() {
                    public void onClick(View v) {

                      try{
                            new MyTask().execute();
                        }catch(Exception e){
                            e.printStackTrace();
                        }
                    }
                });
    }

    public static long copyLarge(InputStream input, OutputStream output)
            throws IOException {
        byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
        long count = 0;
        int n = 0;
        while (-1 != (n = input.read(buffer))) {
            output.write(buffer, 0, n);
            count += n;
        }
        return count;
    }

    public static int copy(InputStream input, OutputStream output) throws IOException {
        long count = copyLarge(input, output);
        if (count > Integer.MAX_VALUE) {
            return -1;
        }
        return (int) count;
    }

    private class MyTask extends AsyncTask<String, Void, String>
    {
        boolean success = false;

        @Override
        protected String doInBackground(String... params) {

            StringBuilder respData = new StringBuilder();
            InputStream stream = null;
            OutputStream os = null;
            HttpURLConnection httpUrlConnection;
            URLConnection conn;
            URL url;

            try {

                url = new URL("my_url/recieveString.php");
                conn = url.openConnection();
                httpUrlConnection = (HttpURLConnection) conn;

                httpUrlConnection.setUseCaches(false);
                //httpUrlConnection.setRequestProperty("User-Agent", "App");
                httpUrlConnection.setConnectTimeout(30000);
                httpUrlConnection.setReadTimeout(30000);
                httpUrlConnection.setRequestMethod("POST");
                httpUrlConnection.setDoOutput(true);
                os = httpUrlConnection.getOutputStream();

                toSubmit = "test";

                stream = new ByteArrayInputStream(toSubmit.getBytes(StandardCharsets.UTF_8));

                copy(stream, os);

                httpUrlConnection.connect();

                int responseCode = httpUrlConnection.getResponseCode();

                if (200 == responseCode) {
                    InputStream is = httpUrlConnection.getInputStream();
                    InputStreamReader isr = null;
                    try {
                        isr = new InputStreamReader(is);
                        char[] buffer = new char[1024];
                        int len;
                        while ((len = isr.read(buffer)) != -1) {
                            respData.append(buffer, 0, len);
                        }
                    } finally {
                        if (isr != null) {
                            isr.close();
                            success = true;
                        }
                    }
                    is.close();
                } else {
                    // use below to get error stream
                    //inputStream = httpUrlConnection.getErrorStream();
                }
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                try {
                stream.close();
                os.flush();

                    os.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }

                return "done";
            }
        }

        @Override
        protected void onPostExecute(String result) {
            super.onPostExecute(result);
            Toast toast = Toast.makeText(getApplicationContext(), "Success", Toast.LENGTH_SHORT);

        }
    }

}

PHP file:

<?php 

$stringRecieved=$_GET["toSubmit"]; 

$file = 'list.txt';

// Write the contents to the file, 
file_put_contents($file, $stringRecieved, FILE_APPEND | LOCK_EX);
?>

Answer 1

If you are POSTing to the server the variable will not be in GET.

$stringRecieved = $_POST["toSubmit"];

Incidentally, it is usually a good idea to provide a wrapper and test that POST is actually being used; it's usually a good idea to sanitize input, and it's usually a good idea to make sure that access is coming from a valid source, none of which your PHP seems to be doing yet.