CODEWITHSUNDEEP
javaarraysswingmultidimensional-array
user2579312
user2579312

Reputation:

Fill multidimensional array from database Java

so I have this code:

public class Welcome extends JFrame {

private JPanel contentPane;
private JTable table;

/**
 * Launch the application.
 */
public static void main(String[] args) {
    EventQueue.invokeLater(new Runnable() {
        public void run() {
            try {
                Welcome frame = new Welcome();
                frame.setVisible(true);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });
}

/**
 * Create the frame.
 */
public Welcome() {
    setAlwaysOnTop(true);
    setResizable(false);
    setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
    setBounds(100, 100, 1024, 768);
    contentPane = new JPanel();
    contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
    setContentPane(contentPane);
    contentPane.setLayout(null);

    ScrollPane scrollPane = new ScrollPane();
    scrollPane.setScrollPosition(new Point(0, 0));
    scrollPane.setBounds(10, 10, 998, 719);
    contentPane.add(scrollPane);

    table = new JTable();
    table.setModel(new DefaultTableModel(
        new Object[][] {

        },
        new String[] {
            "First Name", "Last Name", "Cellphone"
        }
    ));
    table.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
    table.setFillsViewportHeight(true);
    table.setBounds(10, 10, 998, 718);
    contentPane.add(table);
}

}

What I am trying to do is fill the jtable with data from the database, but I don't know how. I am thinking of having a method outside of the initialize method, and create a multidimensional array in there for the jTable to reference. I am targeting this line of code:

new Object[][] {

}

How could I make a multidimensional Object array and populate it with data from the database?? The gui was done using eclipse window builder.

Thanks, Josh

Upvotes: 1

Views: 1679

Answers (2)

mKorbel
mKorbel

Reputation: 109823

How could I make a multidimensional Object array and populate it with data from the database?? The gui was done using eclipse window builder.

  • not I'm disagree everything is simpler, quite simple

  • Database Objects and JDBC methods returns by default (ResultSet) only columns and rows

  • JTable (its underlaying XxxTableModel) is about columns and rows only

  • Swing JComponents and its XxxModel are designated to be reusable, both model and view too

  • back to JDBC and XxxTableModel, my following sentences, all points will be about XxxTableModel

  • there no issue to add, remove, modify row(s), reset to null , modify cell value etc

  • ResultSet returns (if isn'm null) collections of rows and you would need to loop inside, row by row

  • each of row representing a new row for XxxTableModel

  • if isnt there real and important reason to start with DefaultTableModel

  • shortcut, but I'd be suggest to use Vector<Vector<Object>> for DefaultTableModel, and util.List or Vector<Vector<Object>> for AbstractTableModel as underlaying array

  • everything important that I don't want to wrote here is very godd described in Oracle tutorial How to use Tables

  • don't to use null layout, see Oracle tutorials Initial Thread and Event Dispatch Thread

Upvotes: 1

Lee Meador
Lee Meador

Reputation: 12985

There are two common ways to do this, three if you stretch a bit:

ONE

Change this line a bit:

new DefaultTableModel(
    loadTableData(),
    new String[] {
        "First Name", "Last Name", "Cellphone"
    }
)

Then you create a method there in the same class that calls the right classes and loads the database info and creates the 2D Object array containing it.

TWO

Add a place for the data and a way to set it:

private Object[] theData;

public setData(Object[] data) {
    theData = data;
}

Then that line we changed in ONE looks like this:

new DefaultTableModel(
    theData,
    new String[] {
        "First Name", "Last Name", "Cellphone"
    }
)

Finally, you have to have a different class with the main method in it that will load the data from the database, create the instance of the Welcome class and inject the database data by calling setData(loadedData). (This could be done by Spring or Guice as well. Or just call the setter.)

THREE

The third way is to create a whole new class that is a TableModel that knows how to read data from the database. You pass an instance of that class to the JTable and when the data is needed, it can be read.

This is documented lots of places on the web. I'd Google for "Java Swing TableModel database" to find some examples.

Upvotes: 1

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