[hardwired]

Code:

import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
import javax.swing.table.*;

public class MainSortTest implements ActionListener
{
    JButton b1,b2;
    JTable table;
    JComboBox combo;

    public MainSortTest()
    {
        String[] columnNames = {"First Name","Last Name","Age","Test Scores"};
        String[] combodata   = {"First Name","Last Name","Age","Test Scores"};
        // Smith       Dave        12      75
        // Johnson     Bill        14      72
        // Anderson    Sara        11      92
        // Hoyez       Kara        16      83
        // Cruz        Kyle        13      84
//        String[] test = {"","","","",""};
        b1=new JButton("0-9/A-Z");
        b2=new JButton("9-0/Z-A");
        b1.addActionListener(this);
        b2.addActionListener(this);
        combo = new JComboBox(combodata);
        combo.setSelectedIndex(3);
        combo.setEditable(false);
        // The combo selectedIndex == table headerColumn index
        // so there is no need for an ActionListener.
//        combo.addActionListener(this);
        Object[][] rowData = {
            {"Dave", "Smith",    new Integer(12), new Integer(75)},
            {"Bill", "Johnson",  new Integer(14), new Integer(72)},
            {"Sara", "Anderson", new Integer(11), new Integer(92)},
            {"Kara", "Hoyez",    new Integer(16), new Integer(83)},
            {"Kyle", "Cruz",     new Integer(13), new Integer(84)}
        };           
        table = new JTable(new DefaultTableModel(rowData,columnNames));

        JFrame f1 = new JFrame();
        f1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        Container c1 = f1.getContentPane();
        c1.add(new JScrollPane(table));
        JPanel p1 = new JPanel();
//        p1.setSize(400,170);
        p1.add(combo);
        p1.add(b1);
        p1.add(b2);
        c1.add(p1, "Last");
        f1.setSize(400,170);
        f1.setLocation(200,200);
        f1.setVisible(true);
    }

    public static void main(String[] args)
    {
        new MainSortTest();
    }

    public void actionPerformed(ActionEvent event)
    {
        int index = combo.getSelectedIndex();
        JButton button = (JButton)event.getSource();
        boolean ascending = button == b1;
        if(index < 2)
            sortStrings(index, ascending);
        else
            sortIntegers(index, ascending);
    }

    private void sortStrings(int col, boolean ascending)
    {
        // Collect the values in the column.
        TableModel model = table.getModel();
        String[] colValues = new String[model.getRowCount()];
        int[] rowIndices = new int[model.getRowCount()];
        for(int j = 0; j < colValues.length; j++)
        {
            colValues[j] = (String)model.getValueAt(j, col);
            rowIndices[j] = j;
        }

        // Sort both arrays.
        for(int j = 0; j < colValues.length; j++)
        {
            String datum = colValues[j];
            int replaceIndex = j;
            for(int k = j+1; k < colValues.length; k++)
            {
                int n = colValues[k].compareTo(datum);
                if( (ascending && n < 0) || (!ascending && n > 0) )
                {
                    datum = colValues[k];
                    replaceIndex = k;
                }

            }
            if(replaceIndex != j)
            {
                String temp = colValues[j];
                colValues[j] = colValues[replaceIndex];
                colValues[replaceIndex] = temp;
                int tempIndex = rowIndices[j];
                rowIndices[j] = rowIndices[replaceIndex];
                rowIndices[replaceIndex] = tempIndex;
            }
        }
        sortRows(rowIndices);
    }

    private void sortIntegers(int col, boolean ascending)
    {
        TableModel model = table.getModel();
        Integer[] colValues = new Integer[model.getRowCount()];
        int[] rowIndices = new int[model.getRowCount()];
        for(int j = 0; j < colValues.length; j++)
        {
            colValues[j] = (Integer)model.getValueAt(j, col);
            rowIndices[j] = j;
        }

        // Sort arrays.
        for(int j = 0; j < colValues.length; j++)
        {
            Integer datum = colValues[j];
            int replaceIndex = j;
            for(int k = j+1; k < colValues.length; k++)
            {
                int n = colValues[k].compareTo(datum);
                if( (ascending && n < 0) || (!ascending && n > 0) )
                {
                    datum = colValues[k];
                    replaceIndex = k;
                }

            }
            if(replaceIndex != j)
            {
                Integer temp = colValues[j];
                colValues[j] = colValues[replaceIndex];
                colValues[replaceIndex] = temp;
                int tempIndex = rowIndices[j];
                rowIndices[j] = rowIndices[replaceIndex];
                rowIndices[replaceIndex] = tempIndex;
            }
        }
        sortRows(rowIndices);
    }

    private void sortRows(int[] indices)
    {
        Object[][] data = getSortedData(indices);
        Object[] colIds = getColumnIdentifiers();
        DefaultTableModel model = (DefaultTableModel)table.getModel();
        model.setDataVector(data, colIds);
        model.fireTableStructureChanged();
    }

    private Object[][] getSortedData(int[] indices)
    {
        DefaultTableModel model = (DefaultTableModel)table.getModel();
        int rows = model.getRowCount();
        int cols = model.getColumnCount();
        Object[][] data = new Object[rows][cols];
        for(int j = 0; j < rows; j++)
        {
            for(int k = 0; k < cols; k++)
                data[j][k] = model.getValueAt(indices[j], k);
        }
        return data;
    }

    private Object[] getColumnIdentifiers()
    {
        TableColumnModel model = table.getColumnModel();
        int cols = model.getColumnCount();
        Object[] colIds = new Object[cols];
        for(int j = 0; j < cols; j++)
            colIds[j] = model.getColumn(j).getIdentifier();
        return colIds;
    }
}