使用数据库Java的RestApi

Question

I'm learning how to create web services with RESTful Api.

I have a sample database and I want to get data from this database using rest api.

Here is my code:

@GET
@Produces(MediaType.APPLICATION_JSON)
public ArrayList<UserModel> getJson() throws ClassNotFoundException, SQLException {
    Connection connection = DatabaseConnection.getConnection();
    Statement stm = connection.createStatement();
    String sql = "select * from user";
    ResultSet rs = stm.executeQuery(sql);
    ArrayList<UserModel> res = new ArrayList<>();
    while(rs.next())
    {
        UserModel user = new UserModel();
        user.setId(rs.getInt("id"));
        user.setNome(rs.getString("nome")); 
        res.add(user);
    }
    return res;
}

Is there a better or quicker way to obtain data from a database and return the resultSet without the conversation in an ArrayList ?

Answer 1

I think this is already a good, quick and short example. You could restrict the statement to the columns you need to avoid unnecessary data to be loaded:

String sql = "select id, nome from user";