Select all rows in a table using JTable

Question

How do I select all rows in a table without the user selecting them with mouse? For example, I have at a table called InputTable. Using ActionListener/TableModelListener, I can get the selected rows (when the user clicks on them) in a table somewhat in this way:

int[] rows = inputTable.getSelectedRows();

I would now like to select all the rows in the Input table and assign it to say, int [] rows1. Is there a command like getSelectedRows() where I can select all the rows without the user interaction? I know that there is a SelectAll() but I want something specific to the rows alone.

Answer 1

I think you are trying to progamatically select rows of a JTable.

The JTable is just a display mechanism. Instead of selecting rows in the table (view), you select rows in the SelectionModel, so have a look at this small example I made:

import java.util.ArrayList;
import javax.swing.*;
import javax.swing.table.DefaultTableModel;

public class Test extends JFrame {

    public static void main(String[] args) throws Exception {
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                new Test().createAndShowUI();
            }
        });
    }

    private void createAndShowUI() {
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        initComponents(frame);
        frame.pack();
        frame.setVisible(true);
    }

    private void initComponents(JFrame frame) {

        String data[][] = {
            {"1", "2", "3"},
            {"4", "5", "6"},
            {"7", "8", "9"},
            {"10", "11", "12"}
        };

        String col[] = {"Col 1", "Col 2", "Col 3"};

        DefaultTableModel model = new DefaultTableModel(data, col);
        JTable table = new JTable(model);

        //call method to select rows (select all rows)
        selectRows(table, 0, table.getRowCount());

        //call method to return values of selected rows
        ArrayList<Integer> values = getSelectedRowValues(table);

        //prints out each values of the selected rows
        for (Integer integer : values) {
            System.out.println(integer);
        }

        frame.getContentPane().add(new JScrollPane(table));
    }

    private void selectRows(JTable table, int start, int end) {
        // Use this mode to demonstrate the following examples
        table.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
        // Needs to be set or rows cannot be selected
        table.setRowSelectionAllowed(true);
        // Select rows from start to end if start is 0 we change to 1 or leave it (used to preserve coloums headers)
        table.setRowSelectionInterval(start, end - 1);
    }

    /**
     * Will return all selected rows values
     *
     * @param table
     * @return ArrayList<Intger> values of each selected row for all coloumns
     */
    private ArrayList<Integer> getSelectedRowValues(JTable table) {
        ArrayList<Integer> values = new ArrayList<>();
        int[] vals = table.getSelectedRows();
        for (int i = 0; i < vals.length; i++) {
            for (int x = 0; x < table.getColumnCount(); x++) {
                System.out.println(table.getValueAt(i, x));
                values.add(Integer.parseInt((String) table.getValueAt(i, x)));
            }
        }
        return values;
    }
}

The magic happens here:

    private void selectRows(JTable table, int start, int end) {
        // Use this mode to demonstrate the following examples
        table.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
        // Needs to be set or rows cannot be selected
        table.setRowSelectionAllowed(true);
        // Select rows from start to end if start is 0 we change to 1 or leave it (used to preserve coloums headers)
        table.setRowSelectionInterval(start, end - 1);
    }

For more examples have a look here shows you how to use SelectionModel on JTable for rows and colomns