Question

I want to send a JSON like this:

{"reverseme" : "Reverse Me!" }

So I created this Java:

JSONObject jsonToSend = new JSONObject()
    .put("reverseme", "Reverse ME!")

If I transform it to String and send it to my api I have no problems:

HttpClient client = new HttpClient();
HttpPost post = new HttpPost("http://192.168.0.10/api");

List<NameValuePair> postData= new ArrayList<NameValuePair>();
postParams.add(new BasicNameValuePair("json", jsonToSend.toString()));

post.setEntity(new UrlEncodedFormEntity(postData));

There it will go to my PHP API is as simple as this (i’m testing some things):

<?php 
$JSON = json_decode($_POST['json'], true);

print(
    json_encode( Array(
        'reversed' : strrev($JSON['reverseme'])
    ))
); ?>

Finally, Java Code to read the response is this:

HttpResponse httpresponse = client.execute(post);
String jsonstringresponse = EntityUtils.toString(httpresponse.getEntity()); 
JSONObject jsonresponse = new JSONObject(jsonstringresponse);

It gives me this StackTrace:

org.json.JSONException: A JSONObject text must begin with '{' at character 1 of "{\"reversed\": "!EM esreveR"}"
    at org.json.JSONTokener.syntaxError(JSONTokener.java:448)
    at org.json.JSONObject.<init>(JSONObject.java:178)
    at org.json.JSONObject.<init>(JSONObject.java:246)
 -> at com.example.test.MainActivity.onClick(MainActivity.java:67)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:521)
    at android.view.View$1.onClick(View.java:2026)
...

Of course I, as you can see on StackTrace’s last line I have some Android UI that read from a EditText and put JSONresult to a TextView.

The problem is that from server it comes:

"{\"reversed\": "!EM esreveR"}"

What is the problem here? Why does json_encode escape every character? Is it Charset problem or some need of cleaning or what?

Thanks on any advise.

---

UPDATE 1
On Apache error log I found this line:

[error] PHP Warning:  json_encode(): Invalid UTF-8 sequence in argument in /var/www/controllers/api.inc.php on line 4.

I have thought that it could be even a PHP misconfiguration?

---

UPDATE 2

json_encode was receiving a Spanish String, that’s the reason of that error: Reading “Atención” gives error because of ‘ó’.

I’m temporally using stripslashes() and deleting first and last character to make it work.

Answer 1

Was a Server configuration fault and that the PHP was saved on ISO-8859-1 charset so PHP messed with 3 different charsets.