CODEWITHSUNDEEP
javaswingnetbeansjtabledefaulttablemodel
John Vasiliou
John Vasiliou

Reputation: 997

jTable not showing anything after grabbing data from database

I have been trying to get data from my Derby database and populate a jTable created by the Netbeans GUI builder.

I have an account class where the following code is kept:

public static DefaultTableModel buildTableModel() throws SQLException {
    Vector<Vector<Object>> data = new Vector<Vector<Object>>();
    Vector columns = new Vector();
    PreparedStatement ps = null;
    ResultSet rs = null;
    try {
        String stmt = "SELECT * FROM APP.DATAVAULT";
        ps = Main.getPreparedStatement(stmt);
        rs = ps.executeQuery();
        ResultSetMetaData metaData = rs.getMetaData();

        // names of columns
        Vector<String> columnNames = new Vector<String>();
        int columnCount = metaData.getColumnCount();
        for (int column = 1; column <= columnCount; column++) {
            columnNames.add(metaData.getColumnName(column));
        }
        // data of the table
        while (rs.next()) {
            Vector<Object> vector = new Vector<Object>();
            for (int columnIndex = 1; columnIndex <= columnCount; columnIndex++) {
                vector.add(rs.getObject(columnIndex));
            }
            data.add(vector);
        }
    } finally {
        try {
            ps.close();
        } catch (Exception e) {
        }
        try {
            rs.close();
        } catch (Exception e) {
        }
    }
    DefaultTableModel tableModel = new DefaultTableModel(data, columns);
    return tableModel;
}

As you can see it returns a DefaultTableModel with two parameters, data and columns.

Then, within my GUI class I have the following:

My field:

Account acc = new Account();

Constructor:

public SPPMainGUI() throws SQLException {
    initComponents();
    datavaultjTable.setModel(acc.buildTableModel());
}

My main method:

public static void main(String args[]) {
    java.awt.EventQueue.invokeLater(new Runnable() {
        @Override
        public void run() {
            try {
                new SPPMainGUI().setVisible(true);
            } catch (SQLException ex) {
                Logger.getLogger(SPPMainGUI.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
    });
}

The code is set to populate my jTable with ALL data from the datavault table, no matter what user is logged in.

I have data in my datavault table:

enter image description here

And this is what my jTable looks like when I run my program and log in successfully:

enter image description here

This is what it SHOULD look like, but populated:

enter image description here

Where am I going wrong in my code? I've been stumped on this for 2 weeks now.

Upvotes: 3

Views: 5100

Answers (1)

Reimeus
Reimeus

Reputation: 159754

You need to add your columnNames to your columns header data, otherwise nothing will appear in your JTable:

for (int column = 1; column <= columnCount; column++) {
   ...
}
columns.add(columnNames); <--- add this line

Rather than have a redundant variable for this data, you could simply use columnNames for your model instead:

DefaultTableModel tableModel = new DefaultTableModel(data, columnNames);

Upvotes: 2

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