@ApiMethod(name = "addUser")
public UserResponse addUser(User userDetails) {
    UserResponse response = new UserResponse();
    String query = "{ call myDbName.mySPName(?,?,?) }";
    ResultSet rs;

    try{
    String url = null;
    if (SystemProperty.environment.value() == SystemProperty.Environment.Value.Production) {
        // Connecting from App Engine.
        // Load the class that provides the "jdbc:google:mysql://"
        // prefix.
        try {
            Class.forName("com.mysql.jdbc.GoogleDriver");
            url ="jdbc:google:mysql://my-project-name:myDbName?user=root";
        }catch (ClassNotFoundException ex){}
    } else {
        // Connecting from an external network.
        try{
        Class.forName("com.mysql.jdbc.Driver");
        url = "jdbc:mysql://mysql-google-cloud-ip:3306?user=root";
        }catch (ClassNotFoundException ex){}
    }
    Connection conn = DriverManager.getConnection(url);

         CallableStatement stmt = conn.prepareCall(query);
        stmt.setString(1, userDetails.getUserId());
        stmt.setString(2, userDetails.getUserEmail());
        stmt.setString(3, userDetails.getUserName());
        stmt.executeUpdate();
        response.setResult(1);
    }
    catch (SQLException ex) {
        System.out.println(ex.getMessage());
        response.setResult(0);
        log.severe(ex.getMessage()+ex.getStackTrace());
    }
    return response;
}