1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
public class User {
    private String username;
    private String password;
    private String id;
    private String phoneNumber;

    public User() {
    }
    
    public User(String username, String password, String id, String phoneNumber) {
        this.username = username;
        this.password = password;
        this.id = id;
        this.phoneNumber = phoneNumber;
    }
    
    public String getUsername() {
        return username;
    }
    
    public void setUsername(String username) {
        this.username = username;
    }
    
    public String getPassword() {
        return password;
    }
    
    public void setPassword(String password) {
        this.password = password;
    }
    
    public String getId() {
        return id;
    }
    
    public void setId(String id) {
        this.id = id;
    }
    
    public String getPhoneNumber() {
        return phoneNumber;
    }
    
    public void setPhoneNumber(String phoneNumber) {
        this.phoneNumber = phoneNumber;
    }

}
----------------------------------------------------------
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
public class Student {
    private String id;
    private String name;
    private int age;
    private String homeAddress;
    public Student() {

    }
    public Student(String id, String name, int age, String homeAddress) {
        this.id = id;
        this.name = name;
        this.age = age;
        this.homeAddress = homeAddress;
    }
    
    public String getId() {
        return id;
    }
    
    public void setId(String id) {
        this.id = id;
    }
    
    public String getName() {
        return name;
    }
    
    public void setName(String name) {
        this.name = name;
    }
    
    public int getAge() {
        return age;
    }
    
    public void setAge(int age) {
        this.age = age;
    }
    
    public String getHomeAddress() {
        return homeAddress;
    }
    
    public void setHomeAddress(String homeAddress) {
        this.homeAddress = homeAddress;
    }

}
------------------------------------------------------------------
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
import java.util.ArrayList;
import java.util.Random;
import java.util.Scanner;

public class userTest_reallyimportant {
    public static void main(String[] args) {
        ArrayList<User> list = new ArrayList<>();
        Scanner sc = new Scanner(System.in);
        while (true) {
            System.out.println("欢迎来到学生管理系统");
            System.out.println("请选择操作:1.登录 2.注册 3.忘记密码 4.退出");
            String choose = sc.next();
            switch (choose) {
                case "1" -> login(list);
                case "2" -> register(list);
                case "3" -> forgetPassword(list);
                case "4" -> System.exit(0);
                default -> System.out.println("输入有误,请重新输入");
            }
        }
    }
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
public static void login(ArrayList<User> list) {
    Scanner sc = new Scanner(System.in);
    for (int i = 0; i < 3; i++) {
        System.out.println("请输入用户名:");
        String username = sc.next();
        boolean flag = contains(list, username);
        if (!flag) {
            System.out.println("用户名不存在,请输入正确用户名");
            return;
        }
        System.out.println("请输入密码:");
        String password = sc.next();
        while (true) {
            String code = getcode();
            System.out.println("验证码为:" + code);
            System.out.println("请输入验证码:");
            String code1 = sc.next();
            if (!code.equalsIgnoreCase(code1)) {
                System.out.println("验证码错误,请重新输入");
                continue;
            } else {
                break;
            }
        }
        User u = new User(username, password, null, null);
        boolean flag1 = checkcode(list, u);
        if (!flag1) {
            if (i == 2) {
                System.out.println("三次密码错误,账号被锁定");
                return;//结束方法
            } else {
                System.out.println("密码错误,请重新输入你还有" + (2 - i) + "次机会");
            }
        } else {
            System.out.println("登录成功");
            StudentTest_important ss=new StudentTest_important();
            ss.starttest();
            break;
        }
    }

}

public static void register(ArrayList<User> list) {
    Scanner sc = new Scanner(System.in);
    String username;
    while (true) {
        System.out.println("请输入用户名:");
        username = sc.next();
        boolean flag = contains(list, username);
        if (flag) {
            System.out.println("用户名已存在,请重新输入");
            continue;
        } else {
            boolean flag1 = checkname(username);
            if (flag1) {
                break;
            } else {
                System.out.println("用户名不符合要求,请重新输入");
                continue;
            }
        }
    }
    String password;
    while (true) {
        System.out.println("请输入密码:");
        password = sc.next();
        System.out.println("请输入确认密码:");
        String password1 = sc.next();
        if (password.equals(password1)) {
            break;
        } else {
            System.out.println("两次密码不一致,请重新输入");
            continue;
        }
    }
    String id;
    while (true) {
        System.out.println("请输入身份证号:");
        id = sc.next();
        boolean flag2 = checkid(id);
        if (flag2) {
            break;
        } else {
            System.out.println("身份证号不符合要求,请重新输入");
            continue;
        }
    }
    String phoneNumber;
    while (true) {
        System.out.println("请输入手机号:");
        phoneNumber = sc.next();
        boolean flag3 = checksecnumber(phoneNumber);
        if (flag3) {
            break;
        } else {
            System.out.println("手机号不符合要求,请重新输入");
            continue;
        }
    }
    User u = new User(username, password, id, phoneNumber);
    list.add(u);
    System.out.println("注册成功");
}

public static void forgetPassword(ArrayList<User> list) {
    Scanner sc = new Scanner(System.in);
    System.out.println("请输入用户名:");
    String username = sc.next();
    boolean flag = contains(list, username);
    if (!flag) {
        System.out.println("用户名不存在,请输入正确用户名");
        return;
    }
    System.out.println("请输入身份证号:");
    String id = sc.next();
    System.out.println("请输入手机号:");
    String phoneNumber = sc.next();
    int index = getIndex(list, username);
    User u1 = list.get(index);
    User u = new User(username, null, id, phoneNumber);
    String password;
    while (true) {
        if (u1.getId().equals(u.getId()) && u1.getPhoneNumber().equals(u.getPhoneNumber())) {
            System.out.println("请输入新密码:");
            password = sc.next();
            System.out.println("请输入确认密码:");
            String password1 = sc.next();
            if (password.equals(password1)) {
                System.out.println("密码修改成功");
                break;
            } else {
                System.out.println("两次密码不一致,请重新输入");
                continue;
            }
        } else {
            System.out.println("身份证号或手机号错误,请重新输入");
            return;
        }
    }u1.setPassword(password);

}

public static int getIndex(ArrayList<User> list, String username) {
    for (int i = 0; i < list.size(); i++) {
        User u1 = list.get(i);
        if (u1.getUsername().equals(username)) {
            return i;
        }
    }
    return -1;
}

public static String getcode() {
    ArrayList<Character> list = new ArrayList<>();
    for (int i = 0; i < 26; i++) {
        list.add((char) ('a' + i));
        list.add((char) ('A' + i));
    }
    for (int i = 0; i < 10; i++) {
        list.add((char) ('0' + i));
    }
    StringBuilder sb = new StringBuilder();
    Random random = new Random();
    for (int i = 0; i < 5; i++) {
        int index;
        if (i == 4) {
            index = random.nextInt(10) + 52;
            sb.append(list.get(index));
        } else {
            index = random.nextInt(52);
            sb.append(list.get(index));
        }
    }
    for (int i = 0; i < sb.length(); i++) {
        int index = random.nextInt(5);
        char temp = sb.charAt(i);
        sb.setCharAt(i, sb.charAt(index));
        sb.setCharAt(index, temp);
    }
    return sb.toString();
}

public static boolean checkcode(ArrayList<User> list, User u) {
    for (int i = 0; i < list.size(); i++) {
        User u1 = list.get(i);
        if (u1.getUsername().equals(u.getUsername()) && u1.getPassword().equals(u.getPassword())) {
            return true;
        }
    }
    return false;
}

public static boolean contains(ArrayList<User> list, String username) {
    String username1;
    for (int i = 0; i < list.size(); i++) {
        username1 = list.get(i).getUsername();
        if (username1.equals(username)) {
            return true;
        }
    }
    return false;
}

public static boolean checkname(String username) {
    if (username.length() < 3 || username.length() > 13) {
        return false;
    }
    for (int i = 0; i < username.length(); i++) {
        char c = username.charAt(i);
        if (!((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9'))) {
            return false;
        }
    }
    for (int i = 0; i < username.length(); i++) {
        char c = username.charAt(i);
        if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) {
            return true;
        }
    }
    return false;
}

public static boolean checkid(String id) {
    for (int i = 0; i < id.length() - 1; i++) {
        char c = id.charAt(i);
        if (!(c >= '0' && c <= '9')) {
            return false;
        }
    }
    char c = id.charAt(id.length() - 1);
    if ((c >= '0' && c <= '9') || (c == 'x' || c == 'X')) {
        return true;
    }
    return false;
}

public static boolean checksecnumber(String phoneNumber) {
    if (phoneNumber.length() != 11) {
        return false;
    }
    if (phoneNumber.startsWith("0")) return false;
    for (int i = 0; i < phoneNumber.length(); i++) {
        char c = phoneNumber.charAt(i);
        if (!(c >= '0' && c <= '9')) {
            return false;
        }
    }
    return true;
}
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
import java.util.ArrayList;
import java.util.Scanner;

public class StudentTest_important {
    public static void starttest() {
        ArrayList<Student> list = new ArrayList<>();
        loop:
        while (true) {
            System.out.println("------------欢迎来到学生管理系统------------");
            System.out.println("1.添加学生");
            System.out.println("2.删除学生");
            System.out.println("3.修改学生");
            System.out.println("4.查询学生");
            System.out.println("5.退出系统");
            System.out.println("请输入你的选择：");
            Scanner sc = new Scanner(System.in);
            String choose;
            choose = sc.next();
            switch (choose) {
                case "1" -> addStudent(list);
                case "2" -> deleteStudent(list);
                case "3" -> updateStudent(list);
                case "4" -> queryStudent(list);
                case "5" -> {
                    System.out.println("退出系统");
                    //break loop;
                    System.exit(0);
                }
                default -> System.out.println("输入有误，请重新输入");
            }
        }
    }
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
public static void addStudent(ArrayList<Student> list) {
    Scanner sc = new Scanner(System.in);
    Student st = new Student();
    while (true) {
        System.out.println("请输入学生学号：");
        String id = sc.next();
        boolean flag = contains(list, id);
        if (flag) {
            System.out.println("学号已存在，请重新输入");
        } else {
            System.out.println("学号不存在,请继续输入");
            st.setId(id);
            break;
        }
    }
    System.out.println("请输入学生姓名：");
    String name = sc.next();
    st.setName(name);
    System.out.println("请输入学生年龄：");
    int age = sc.nextInt();
    st.setAge(age);
    System.out.println("请输入学生家庭住址：");
    String homeAddress = sc.next();
    st.setHomeAddress(homeAddress);
    list.add(st);
    System.out.println("添加学生成功");
}

public static void deleteStudent(ArrayList<Student> list) {
    Scanner sc = new Scanner(System.in);
    System.out.println("请输入要删除的学生学号：");
    String id = sc.next();
    boolean flag = contains(list, id);
    if (flag) {
        for (int i = 0; i < list.size(); i++) {
            Student st = list.get(i);
            if (st.getId().equals(id)) {
                list.remove(i);
                System.out.println("删除成功");
                break;
            }
        }
    } else {
        System.out.println("学号不存在");
    }
}

public static void updateStudent(ArrayList<Student> list) {
    System.out.println("修改学生");
    Scanner sc = new Scanner(System.in);
    System.out.println("请输入要修改的学生学号：");
    String id = sc.next();
    boolean flag = contains(list, id);
    if (flag) {
        loop:for (int i = 0; i < list.size(); i++) {
            Student st = list.get(i);
            if (st.getId().equals(id)) {
                    System.out.println("请输入修改后的学号:");
                    st.setId(sc.next());
                    if (contains(list, st.getId())) {
                        System.out.println("请输入修改后的姓名:");
                        st.setName(sc.next());
                        System.out.println("请输入修改后的年龄:");
                        st.setAge(sc.nextInt());
                        System.out.println("请输入修改后的家庭住址:");
                        st.setHomeAddress(sc.next());
                        System.out.println("修改成功");
                        break loop;
                    }else {
                        System.out.println("学号不存在");
                        break;
                    }
            }
        }
    } else {
        System.out.println("学号不存在");
    }
}

public static void queryStudent(ArrayList<Student> list) {
    if (list.size() == 0) {
        System.out.println("无信息，请添加后重试");
        return;
    }
    System.out.println("学号\t\t姓名\t\t年龄\t\t家庭住址");
    for (int i = 0; i < list.size(); i++) {
        Student st = list.get(i);
        System.out.println(st.getId() + "\t\t" + st.getName() + "\t\t" + st.getAge() + "\t\t" + st.getHomeAddress());
    }
}

public static boolean contains(ArrayList<Student> list, String id) {
    for (int i = 0; i < list.size(); i++) {
        Student st = list.get(i);
        if (st.getId().equals(id)) {
            return true;
        }
    }
    return false;
}
}
总共两个类,两个大的测试方法组成