Create Ticket from Java

[DbSchema]

I try to create a ticket from Java. I am not sure what I do wrong, maybe you can help me. I get an HTTP 400 error. Here is my code:

URL url = new URL ("https://support.dbschema.com/api/v1/tickets");
        HttpURLConnection con = (HttpURLConnection)url.openConnection();
        con.setRequestMethod("POST");
        con.setRequestProperty("Content-Type", "application/json; utf-8");
        con.setRequestProperty("Accept", "application/json");
        con.setDoOutput(true);
        String jsonInputString = "{\n" +
                "  'title': 'Help me!',\n" +
                "  'group': 'Technical',\n" +
                "  'customer': 'email_of_existing_customer@example.com',\n" +
                "  'article': {\n" +
                "    'subject': 'some subject',\n" +
                "    'body': 'some message',\n" +
                "    'type': 'note',\n" +
                "    'internal': false\n" +
                "  },\n" +
                "  'note': 'some note',\n" +
                "}";
        try( OutputStream os = con.getOutputStream() ) {
            byte[] input = jsonInputString.getBytes( StandardCharsets.UTF_8 );
            os.write(input, 0, input.length);
        }
        StringBuilder response = new StringBuilder();
        try( BufferedReader br = new BufferedReader( new InputStreamReader(con.getInputStream(), StandardCharsets.UTF_8 ))) {
            String line;
            while ((line = br.readLine()) != null) {
                response.append(line.trim());
            }
            System.out.println(response.toString());
        }

[MrGeneration]

Please use the template… it helps to know your system better.

* Used Zammad version: 
* Used Zammad installation source: (source, package, ...)
* Operating system: 
* Browser + version: 


### Expected behavior:

* 


### Actual behavior:

* 


### Steps to reproduce the behavior:

* 

Beside, those kind of issues normally have a error message in the production log. It might help, at least if “400 Bad request” is everything your script returns.