1 /**
2 * Created by xc on 2019/11/23
3 * 生成随机密码：6位数字
4 */
5 public class Test7_4 {
6
7 public static void main(String[] args) {
8 System.out.println(randomPassword());//382630
9 }
10
11 public static String randomPassword() {
12 char[] chars = new char[6];
13 Random rnd = new Random();
14 for (int i = 0; i < 6; i++) {
15 chars[i] = (char) ('0' + rnd.nextInt(10));
16 }
17 return new String(chars);
18 }
19
20 }
1 /**
2 * Created by xc on 2019/11/23
3 * 生成随机密码：简单8位
4 * 8位密码，字符可能由大写字母、小写字母、数字和特殊符号组成
5 */
6 public class Test7_5 {
7
8 private static final String SPECIAL_CHARS = "!@#$%^&*_=+-/";
9
10 public static void main(String[] args) {
11 System.out.println(randomPassword());//ejgY^14*
12 }
13
14 private static char nextChar(Random rnd) {
15 switch (rnd.nextInt(4)) {
16 case 0:
17 return (char) ('a' + rnd.nextInt(26));
18 case 1:
19 return (char) ('A' + rnd.nextInt(26));
20 case 2:
21 return (char) ('0' + rnd.nextInt(10));
22 default:
23 return SPECIAL_CHARS.charAt(rnd.nextInt(SPECIAL_CHARS.length()));
24 }
25 }
26
27 public static String randomPassword() {
28 char[] chars = new char[8];
29 Random rnd = new Random();
30 for (int i = 0; i < 8; i++) {
31 chars[i] = nextChar(rnd);
32 }
33 return new String(chars);
34 }
35
36 }
1 /**
2 * Created by xc on 2019/11/23
3 * 生成随机密码：复杂8位
4 */
5 public class Test7_6 {
6
7 private static final String SPECIAL_CHARS = "!@#$%^&*_=+-/";
8
9 public static void main(String[] args) {
10 System.out.println(randomPassword());//Q*82-/zQ
11 }
12
13 private static int nextIndex(char[] chars, Random rnd) {
14 int index = rnd.nextInt(chars.length);
15 while (chars[index] != 0) {
16 index = rnd.nextInt(chars.length);
17 }
18 return index;
19 }
20
21 private static char nextSpecialChar(Random rnd) {
22 return SPECIAL_CHARS.charAt(rnd.nextInt(SPECIAL_CHARS.length()));
23 }
24
25 private static char nextUpperlLetter(Random rnd) {
26 return (char) ('A' + rnd.nextInt(26));
27 }
28
29 private static char nextLowerLetter(Random rnd) {
30 return (char) ('a' + rnd.nextInt(26));
31 }
32
33 private static char nextNumLetter(Random rnd) {
34 return (char) ('0' + rnd.nextInt(10));
35 }
36
37 public static String randomPassword() {
38 char[] chars = new char[8];
39 Random rnd = new Random();
40 chars[nextIndex(chars, rnd)] = nextSpecialChar(rnd);
41 chars[nextIndex(chars, rnd)] = nextUpperlLetter(rnd);
42 chars[nextIndex(chars, rnd)] = nextLowerLetter(rnd);
43 chars[nextIndex(chars, rnd)] = nextNumLetter(rnd);
44 for (int i = 0; i < 8; i++) {
45 if (chars[i] == 0) {
46 chars[i] = nextChar(rnd);
47 }
48 }
49 return new String(chars);
50 }
51
52 private static char nextChar(Random rnd) {
53 switch (rnd.nextInt(4)) {
54 case 0:
55 return (char) ('a' + rnd.nextInt(26));
56 case 1:
57 return (char) ('A' + rnd.nextInt(26));
58 case 2:
59 return (char) ('0' + rnd.nextInt(10));
60 default:
61 return SPECIAL_CHARS.charAt(rnd.nextInt(SPECIAL_CHARS.length()));
62 }
63 }
64
65 }
