Keycloak Java login

gistfile1.txt

final String content = "client_id=" + appName + "&username=" + user + "&password=" + password + "&grant_type=password"
final byte[] rawContent = content.getBytes(PlatformConstants.CHARSET);
final URI url = new URI(authEndpoint + "/auth/realms/" + realmName + "/protocol/openid-connect/token");
final HttpURLConnection connection = new DefaultHttpURLConnectionFactory().create(url);
connection.setRequestMethod(RequestMethod.POST.getRawName());
connection.setRequestProperty("charset", "UTF-8");
connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
connection.setRequestProperty("Content-Length", rawContent.length + "");
connection.setDoOutput(true);
connection.setDoInput(true);
try {
    final OutputStream w = connection.getOutputStream();
    w.write(rawContent);
    w.close();
} catch (IOException e) {
    throw new DolphinRuntimeException("Looks like the security server is not reachable", e);
}

final int responseCode = connection.getResponseCode();
if(responseCode == 401) {
    throw new DolphinRuntimeException("Invalid login!");
}

final ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
try {
    final InputStream is = connection.getInputStream();
    int read = is.read();
    while (read != -1) {
        byteArrayOutputStream.write(read);
        read = is.read();
    }
} catch (FileNotFoundException e) {
    throw new DolphinRuntimeException("Maybe the realm or application is not defined in the keycloak server", e);
}
final byte[] rawInput = byteArrayOutputStream.toByteArray();
final String input = new String(rawInput);

final Gson gson = PlatformClient.getService(Gson.class);
final KeycloakOpenidConnectResult result = gson.fromJson(input, KeycloakOpenidConnectResult.class);