第五次学习笔记

1 import java.awt.BorderLayout;

2 import java.awt.Color;

3 import java.awt.Font;

4 import java.awt.event.ActionEvent;

5 import java.awt.event.ActionListener;

6 import java.io.File;

7 import java.util.HashMap;

8 import javax.swing.JComboBox;

9 import javax.swing.JFrame;

10 import javax.swing.JLabel;

11 import javax.swing.JPanel;

12 import javax.swing.JScrollPane;

13 import javax.swing.JTextArea;

14 import javax.swing.border.EmptyBorder;

15

16 /

17 * 文件排序系统。

18 *

19 * @author

20

21 /

22 public class FileUtils {

23

24 /

25 * 用于存储分类后的文件。

26 * key:后缀名， value:StringBuilder存储对应的文件。

27 */

28 private HashMap resultMap = new HashMap();

29

30 /**

31 * 监听文件目录。

32 *

33 * @param dir 目录。

34 * @throws IllegalAccessException 访问非法异常。

35 */

36 public void listenDirectory(File dir) throws IllegalAccessException {

37 if (!dir.exists()) {

38 throw new IllegalAccessException("目录" + dir + "不存在。");

39 }

40

41 if (!dir.isDirectory()) {

42 throw new IllegalArgumentException(dir + "不是目录");

43 }

44

45 String[] fileNames = dir.list();

46 resultMap.put("all", new StringBuilder()); //默认所有文件。

47 resultMap.put("folder", new StringBuilder()); //文件夹形式。

48

49 //后缀。

50 String suffix;

51 for (String fileName : fileNames) {

52 resultMap.get("all").append(fileName + "\n");

53 if (fileName.indexOf(".") > 0) {

54 suffix = fileName.substring(fileName.indexOf("."), fileName.length());

55

56 if (!resultMap.containsKey(suffix)) {

57 StringBuilder stringBuilder = new StringBuilder();

58 stringBuilder.append(fileName + "\n");

59 resultMap.put(suffix, stringBuilder);

60 } else {

61 resultMap.get(suffix).append(fileName + "\n");

62 }

63 } else {

64 resultMap.get("folder").append(fileName + "\n");

65 }

66 }

67

68 buildGUI();

69 }

70

71 /**

72 * 搭建GUI。

73 */

74 public void buildGUI() {

75 final JTextArea fileList = new JTextArea();

76 fileList.setText(resultMap.get("all").toString());

77 String[] likes = new String[resultMap.keySet().size()];

78 resultMap.keySet().toArray(likes);

79 final JComboBox combox = new JComboBox(likes);

80

81 JFrame frm = new JFrame();

82 frm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

83

84 JPanel contentPane = new JPanel();

85 contentPane.setBorder(new EmptyBorder(6, 10, 10, 10));

86 contentPane.setLayout(new BorderLayout(5, 5));

87 contentPane.add(combox, BorderLayout.NORTH);

88

89 JPanel pane = new JPanel();

90 pane.setLayout(new BorderLayout(8, 8));

91

92 JLabel label = new JLabel(" File lists :");

93 label.setFont(new Font("Serif", Font.PLAIN, 16));

94

95 fileList.setForeground(new Color(140, 171, 226));

96 fileList.setBackground(Color.white);

97 fileList.setSelectedTextColor(new Color(87, 49, 134));

98 fileList.setForeground(Color.black);

99

100 JScrollPane scrollPane = new JScrollPane(fileList);

101 scrollPane.setColumnHeaderView(label);

102

103 pane.add(scrollPane, BorderLayout.CENTER);

104 contentPane.add(pane, BorderLayout.CENTER);

105 frm.add(contentPane);

106 frm.setBounds(500, 300, 300, 400);

107 frm.setVisible(true);

108

109 //JComboBox事件监听。

110 combox.addActionListener(new ActionListener() {

111 @Override

112 public void actionPerformed(ActionEvent e) {

113 try {

114 // 获取组合框的item

115 String item = (String) combox.getItemAt(combox.getSelectedIndex());

116 fileList.setText(resultMap.get(item).toString());

117 } catch (Exception e1) {

118 e1.printStackTrace();

119 }

120 }

121 });

122 }

123

124 public static void main(String[] args) {

125 String path = "D:\";

126 try {

127 new FileUtils().listenDirectory(new File(path));

128 } catch (IllegalAccessException e) {

129 e.printStackTrace();

130 }

131 }

132 }