/*
This program is a part of the companion code for Core Java 8th ed.
(http://horstmann.com/corejava)
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.TableModel;
/**
* This program shows how to build a table from a table model.
* @version 1.02 2007-08-01
* @author Cay Horstmann
*/
public class InvestmentTable
{
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
JFrame frame = new InvestmentTableFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
});
}
}
/**
* This frame contains the investment table.
*/
class InvestmentTableFrame extends JFrame
{
public InvestmentTableFrame()
{
setTitle("InvestmentTable");
setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
TableModel model = new InvestmentTableModel(30, 5, 10);
JTable table = new JTable(model);
add(new JScrollPane(table));
}
private static final int DEFAULT_WIDTH = 600;
private static final int DEFAULT_HEIGHT = 300;
}
/**
* This table model computes the cell entries each time they are requested. The table contents shows
* the growth of an investment for a number of years under different interest rates.
*/
class InvestmentTableModel extends AbstractTableModel
{
/**
* Constructs an investment table model.
* @param y the number of years
* @param r1 the lowest interest rate to tabulate
* @param r2 the highest interest rate to tabulate
*/
public InvestmentTableModel(int y, int r1, int r2)
{
years = y;
minRate = r1;
maxRate = r2;
}
public int getRowCount()
{
return years;
}
public int getColumnCount()
{
return maxRate - minRate + 1;
}
public Object getValueAt(int r, int c)
{
double rate = (c + minRate) / 100.0;
int nperiods = r;
double futureBalance = INITIAL_BALANCE * Math.pow(1 + rate, nperiods);
return String.format("%.2f", futureBalance);
}
public String getColumnName(int c)
{
return (c + minRate) + "%";
}
private int years;
private int minRate;
private int maxRate;
private static double INITIAL_BALANCE = 100000.0;
}
|
