Android, PHP and UTF-8 problems

Question

I am doing some experiments with android and PHP, the mobile device is a client posting some code via a HTTP POST method to the PHP. I am using the following code:

            URL url = new URL(host + webapp + syncURL);

            HttpURLConnection con = (HttpURLConnection) url.openConnection();
            con.setRequestMethod("POST");
            con.setRequestProperty("Accept-Charset", "UTF-8");
            con.setFixedLengthStreamingMode(postParams.getBytes().length);
            con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded; charset=utf-8");

            con.setDoOutput(true);

            //send the POST out
            PrintWriter out = new PrintWriter(con.getOutputStream());
            out.print(postParams);
            out.close();

The variable postParams is in the following form:

Parámetros: hora=22%3A15%3A02&precision=25.1520004272461&fecha=2013-09-18&data=%5B%22S%C3%AD%22%5D

The original data is hora=22:15:02,precision=25.1520004272461,fecha=2013-09-18 and data=["Sí"] stored as a key-value in a Map object.

For transform the Map in postParams I use the following code:

        StringBuilder parametersAsQueryString = new StringBuilder();
        try {
            if (parameters != null) {
                boolean firstParameter = true;

                for (String parameterName : parameters.keySet()) {
                    if (!firstParameter) {
                        parametersAsQueryString.append(PARAMETER_DELIMITER);
                    }

                    Log.d(LOG_TAG, "Parámetro: " + parameterName + ", value: " + parameters.get(parameterName));

                    // Agregamos el nombre del parámetro
                    parametersAsQueryString.append(parameterName).append(PARAMETER_EQUALS_CHAR);

                    // Agregamos el valor del parámetro
                    try {
                        parametersAsQueryString
                            .append(URLEncoder.encode(parameters.get(parameterName), "UTF-8"));
                    } catch(NullPointerException npe) {
                        parametersAsQueryString
                                .append(URLEncoder.encode("", "UTF-8"));
                    }

                    firstParameter = false;
                }
            }
        } catch (UnsupportedEncodingException uee) {
            Log.d(LOG_TAG, "Error: " + uee);

But, in the data in the database is show as ["SÃ"] . The database is a PostgreSQL database with encoding UTF-8 , so I don't believe that the problem be there. Could someone help me? Thanks in advance.

Answer 1

Maybe Special characters are not allowed from android-to-webservice and viceversa.

If you have any special character/letter then you need to replace it with respective escape character sequence. Have a look here

I had the same problem with some french characters eg á and i solved it by replacing á with \á

eg if you want to print "Parámetros" then simply do.

String str="Parámetros";
str=str.replace("á","\u00e1");
Log.i("MyClass",str);

Now you can pass str between two platforms!

Answer 2

Since String objects in Java don't handle utf-8, what you need to do is to send the data to PHP as a byteArray, you can use the ByteArrayWriter object instead of

PrintWriter out = new PrintWriter(con.getOutputStream());

You can use

ByteArrayWriter = new ByteArrayWriter(con.getOutputStream());

since in your header you already specify utf-8 encoding, PHP should understand it, just make sure to send the data as bytes