Question

This function returns ArrayList that contains some data from DB:

public ArrayList<ArrayList<Object>> executeQuery(String host, String database,
            String sqlStatement)

I need to populate JTable with this ArrayList. For instance, one of possible outputs could be (3 rows, 4 columns):

[[1, 10, 1, 2], [2, 11, 2, 1], [3, 12, 3, 1]]

I know that a table model should be created, but what if the columns are not known prior?

Answer 1

You can use the methods of DatabaseMetaData to find the number and names of a table’s attributes. You can use Class Literals as Runtime-Type Tokens to populate your data structure dynamically. Also consider programming to the interface, e.g List<List<Number>> or List<List<Integer>>.