Java自動計算表格某一數字列的和

Java自動計算表格某一數字列的和（一）：

1. package com.han;
3. import java.awt.BorderLayout;
4. import java.awt.Container;
5. import java.util.Vector;
7. import javax.swing.JFrame;
8. import javax.swing.JLabel;
9. import javax.swing.JOptionPane;
10. import javax.swing.JPanel;
11. import javax.swing.JScrollPane;
12. import javax.swing.JTable;
13. import javax.swing.JTextField;
14. import javax.swing.event.TableModelEvent;
15. import javax.swing.event.TableModelListener;
16. import javax.swing.table.DefaultTableModel;
18. /**
19. * 自動計算表格某一數字列的和
20. * @author HAN
21. *
22. */
23. public class TabelModelEvent_2 extends JFrame {
25. /**
26. *
27. */
28. private static final long serialVersionUID = 7045416728019138021L;
30. float sum = 0;
32. public TabelModelEvent_2() {
33. // TODO Auto-generated constructor stub
34. final Container container = getContentPane();
35. JScrollPane scrollPane = new JScrollPane();
36. Vector<String> tableNames = new Vector<String>();
37. tableNames.add("數字列");
38. Vector<Vector<String>> tableValues = new Vector<Vector<String>>();
39. for (int i = 0; i < 4; i++) {
40. Vector<String> vector = new Vector<String>();
41. vector.add(null);
42. tableValues.add(vector);
43. }
44. final DefaultTableModel defaultTabelModel = new DefaultTableModel(
45. tableValues, tableNames);
46. JTable table = new JTable(defaultTabelModel);
47. scrollPane.setViewportView(table);
48. container.add(scrollPane, BorderLayout.CENTER);
49. JPanel panel = new JPanel();
50. JLabel label = new JLabel("數字列總和：");
51. final JTextField textField = new JTextField(10);
52. panel.add(label);
53. panel.add(textField);
54. container.add(panel, BorderLayout.SOUTH);
56. defaultTabelModel.addTableModelListener(new TableModelListener() {
58. @Override
59. public void tableChanged(TableModelEvent e) {
60. // TODO Auto-generated method stub
61. if (e.getType() == TableModelEvent.UPDATE) {
62. int row = e.getFirstRow();
63. int column = e.getColumn();
65. // keep that every cell value is float or null.
66. try {
67. Float.parseFloat((String) defaultTabelModel.getValueAt(
68. row, column));
69. } catch (NumberFormatException e1) {
70. JOptionPane.showMessageDialog(container,
71. "Your input object is not a float type");
72. defaultTabelModel.setValueAt(null, row, column);
73. } catch (NullPointerException e2) {
74. // do nothing
75. }
77. for (int i = 0; i < 4; i++) {
78. Object cellValue = defaultTabelModel.getValueAt(i, 0);
79. if (cellValue != null) {
81. float floatValue = Float
82. .parseFloat((String) cellValue);
83. sum += floatValue;
85. }
86. }
87. }
88. textField.setText(new Float(sum).toString());
89. sum = 0;
90. }
92. });
93. }
95. /**
96. * @param args
97. */
98. public static void main(String[] args) {
99. // TODO Auto-generated method stub
100. TabelModelEvent_2 frame = new TabelModelEvent_2();
101. frame.setTitle("自動計算表格某一數字列的和");
102. frame.pack();
103. frame.setVisible(true);
104. frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
105. }
107. }