90 lines
2.0 KiB
Java
90 lines
2.0 KiB
Java
package tableModel;
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import java.awt.*;
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import javax.swing.*;
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import javax.swing.table.*;
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/**
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* This program shows how to build a table from a table model.
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* @version 1.03 2006-05-10
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* @author Cay Horstmann
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*/
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public class InvestmentTable
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{
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public static void main(String[] args)
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{
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EventQueue.invokeLater(() ->
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{
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JFrame frame = new InvestmentTableFrame();
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frame.setTitle("InvestmentTable");
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frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
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frame.setVisible(true);
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});
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}
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}
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/**
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* This frame contains the investment table.
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*/
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class InvestmentTableFrame extends JFrame
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{
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public InvestmentTableFrame()
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{
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TableModel model = new InvestmentTableModel(30, 5, 10);
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JTable table = new JTable(model);
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add(new JScrollPane(table));
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pack();
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}
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}
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/**
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* This table model computes the cell entries each time they are requested. The table contents shows
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* the growth of an investment for a number of years under different interest rates.
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*/
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class InvestmentTableModel extends AbstractTableModel
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{
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private static double INITIAL_BALANCE = 100000.0;
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private int years;
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private int minRate;
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private int maxRate;
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/**
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* Constructs an investment table model.
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* @param y the number of years
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* @param r1 the lowest interest rate to tabulate
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* @param r2 the highest interest rate to tabulate
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*/
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public InvestmentTableModel(int y, int r1, int r2)
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{
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years = y;
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minRate = r1;
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maxRate = r2;
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}
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public int getRowCount()
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{
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return years;
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}
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public int getColumnCount()
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{
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return maxRate - minRate + 1;
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}
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public Object getValueAt(int r, int c)
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{
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double rate = (c + minRate) / 100.0;
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int nperiods = r;
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double futureBalance = INITIAL_BALANCE * Math.pow(1 + rate, nperiods);
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return String.format("%.2f", futureBalance);
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}
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public String getColumnName(int c)
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{
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return (c + minRate) + "%";
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}
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}
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