1.  package task3;
2.
3.  import java.awt.EventQueue;
4.  import java.awt.event.ActionEvent;
5.  import java.awt.event.ActionListener;
6.  import java.io.File;
7.  import java.io.FileInputStream;
8.  import java.io.FileNotFoundException;
9.  import java.io.IOException;
10.
11. import javax.swing.JButton;
12. import javax.swing.JFileChooser;
13. import javax.swing.JFrame;
14. import javax.swing.JPanel;
15. import javax.swing.border.EmptyBorder;
16.
17. public class Task3 extends JFrame {
18.
19.     private static final long serialVersionUID = 1L;
20.     private JPanel contentPane;
21.     private long lenOld;
22.     private long lenNew;
23.     private File file;
24.     static char[] Alph;
25.     static double[] cum_freq;
26.     static String tab;
27.     private static char[] chars;
28.
29.     static double low = 0.0;
30.     static double high = 1.0;
31.
32.     private static void encode_symbol(int symbol) {
33.         double range = high - low;
34.         high = low + range * cum_freq[symbol];
35.         if (symbol == 0) {
36.             low = low + range * 0;
37.         } else {
38.             low = low + range * cum_freq[symbol - 1];
39.         }
40.         System.out.println(low + " - " + high);
41.     }
42.
43.     private static void sortik(double[] arr) {
44.         for (int i = arr.length - 1; i > 0; i--) {
45.             for (int j = 0; j < i; j++) {
46.                 if (arr[j] < arr[j + 1]) {
47.                     double tmp = arr[j];
48.                     arr[j] = arr[j + 1];
49.                     arr[j + 1] = tmp;
50.                 }
51.             }
52.         }
53.     }
54.
55.     private static void encode(String source) {
56.         char[] etap = source.toCharArray();
57.         tab = "";
58.         for (int i = 0; i < etap.length - 1; i++) {
59.             if (tab.contains(source.substring(i, i + 1))) {
60.                 continue;
61.             } else {
62.                 tab += etap[i];
63.             }
64.         }
65.         int nums = tab.length();
66.         int counter = 0;
67.         Alph = new char[nums];
68.         cum_freq = new double[nums];
69.         double[] cum = new double[nums];
70.         char[] table = tab.toCharArray();
71.         for (int i = 0; i < tab.length(); i++) {
72.             Alph[i] = table[i];
73.             System.out.println(Alph[i]);
74.         }
75.         chars = source.toCharArray();
76.         for (int i = 0; i < nums; i++) {
77.             for (int j = 0; j < chars.length; j++) {
78.                 if (Alph[i] == chars[j])
79.                     counter++;
80.             }
81.             cum[i] = (double) counter / chars.length;
82.             counter = 0;
83.         }
84.         sortik(cum);
85.
86.         counter = 0;
87.         for (int i = 0; i < nums; i++) {
88.             counter = i;
89.             if (counter == 0) {
90.                 cum_freq[i] = cum[i];
91.             } else {
92.                 while (counter >= 0) {
93.                     cum_freq[i] += cum[counter];
94.                     counter--;
95.                 }
96.             }
97.         }
98.     }
99.
100.        public Task3() {
101.            setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
102.            setSize(360, 200);
103.            contentPane = new JPanel();
104.            contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
105.            setContentPane(contentPane);
106.            contentPane.setLayout(null);
107.
108.            JButton btnEncode = new JButton("Шифр");
109.
110.            JButton btnChoose = new JButton("Файл");
111.            btnChoose.addActionListener(new ActionListener() {
112.                public void actionPerformed(ActionEvent arg0) {
113.                    JFileChooser fileopen = new JFileChooser();
114.                    int ret = fileopen.showDialog(null, "Открыть файл");
115.                    if (ret == JFileChooser.APPROVE_OPTION) {
116.                        file = fileopen.getSelectedFile();
117.                        String name = file.getName();
118.                        if (name.contains(".txt")) {
119.                            System.out.println("Имя файла " + name);
120.                            btnEncode.setEnabled(true);
121.                            lenOld = file.length();
122.                            System.out.println("Старый размер " + lenOld + "b");
123.                        } else {
124.                            System.out.println("Ошибка");
125.                        }
126.                    }
127.                }
128.            });
129.            btnChoose.setBounds(110, 6, 89, 23);
130.            contentPane.add(btnChoose);
131.
132.            btnEncode.addActionListener(new ActionListener() {
133.                public void actionPerformed(ActionEvent arg0) {
134.                    String path = file.getPath();
135.                    String textOld = "";
136.
137.                    try {
138.                        @SuppressWarnings("resource")
139.                        FileInputStream inFile = new FileInputStream(path);
140.                        byte[] str = new byte[inFile.available()];
141.                        inFile.read(str);
142.                        textOld = new String(str);
143.                        encode(textOld);
144.                    } catch (FileNotFoundException e) {
145.                        System.out.println("Ошибка");
146.                        System.out.println("Ошибка");
147.                        e.printStackTrace();
148.                    } catch (IOException e) {
149.                        System.out.println("Ошибка");
150.                        System.out.println("Ошибка");
151.                        e.printStackTrace();
152.                    }
153.
154.                    lenNew = file.length();
155.                    System.out.println("Новый размер " + lenNew + "b");
156.                    System.out.println((lenOld - lenNew) + "b");
157.
158.                    btnEncode.setEnabled(false);
159.
160.                    btnChoose.setEnabled(false);
161.                }
162.            });
163.            btnEncode.setBounds(110, 36, 89, 23);
164.            btnEncode.setEnabled(false);
165.            contentPane.add(btnEncode);
166.        }
167.
168.        public static void main(String[] args) {
169.            EventQueue.invokeLater(new Runnable() {
170.                public void run() {
171.                    try {
172.                        Task3 frame = new Task3();
173.                        frame.setVisible(true);
174.                    } catch (Exception e) {
175.                        e.printStackTrace();
176.                    }
177.                }
178.            });
179.        }
180.    }