1. import java.util.Random;
2.
3. public class PasswordGenerator {
4.
5.     private static final String CAPITAL_LETTERS =
6.
7.             "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
8.
9.     private static final String SMALL_LETTERS =
10.
11.             "abcdefghijklmnopqrstuvwxyz";
12.
13.     private static final String DIGITS = "0123456789";
14.
15.     private static final String SPECIAL_CHARS =
16.
17.             "~!@#$%^&*()_+=`{}[]\\|':;.,/?<>";
18.
19.     private static final String ALL_CHARS =
20.
21.             CAPITAL_LETTERS + SMALL_LETTERS + DIGITS + SPECIAL_CHARS;
22.
23.     private static Random rnd = new Random();
24.
25.    public static void main(String[] args) {
26.
27.     StringBuilder password = new StringBuilder();
28.
29.     for (int i=1; i<=2; i++) {
30.
31.         char capitalLetter = generateChar(CAPITAL_LETTERS);
32.
33.         insertAtRandomPosition(password, capitalLetter);
34.
35.     }
36.
37.     for (int i=1; i<=2; i++) {
38.
39.         char smallLetter = generateChar(SMALL_LETTERS);
40.
41.         insertAtRandomPosition(password, smallLetter);
42.
43.     }
44.
45.     char digit = generateChar(DIGITS);
46.
47.     insertAtRandomPosition(password, digit);
48.
49.     for (int i=1; i<=3; i++) {
50.
51.         char specialChar = generateChar(SPECIAL_CHARS);
52.
53.         insertAtRandomPosition(password, specialChar);
54.
55.     }
56.
57.     int count = rnd.nextInt(8);
58.
59.     for (int i=1; i<=count; i++) {
60.
61.         char specialChar = generateChar(ALL_CHARS);
62.
63.         insertAtRandomPosition(password, specialChar);
64.
65.     }
66.
67.
68.
69.     System.out.println(password);
70.
71. }
72.
73.
74.
75. private static void insertAtRandomPosition(
76.
77.         StringBuilder password, char character) {
78.
79.     int randomPosition = rnd.nextInt(password.length()+1);
80.
81.     password.insert(randomPosition, character);
82.
83. }
84.
85.
86.
87. private static char generateChar(String availableChars) {
88.
89.     int randomIndex = rnd.nextInt(availableChars.length());
90.
91.     char randomChar = availableChars.charAt(randomIndex);
92.
93.     return randomChar;
94.
95.
96.     }
97. }