使用对象数组实现学生管理系统

 1 package day04test;
 2 import com.sun.org.apache.bcel.internal.classfile.Code;
 3 import day04_2.Stu;
 4 
 5 import java.util.Scanner;
 6 
 7 /**
 8  * @author liuwenlong
 9  * @create 2020-06-30 17:28:04
10  */
11 public class TestStuMgr {
12 
13     public static Scanner input = new Scanner(System.in);
14     //记录插入学生的总数量
15     public static int i = 0;
16 
17 
18 
19     public static void main(String[] args) {
20 
21         boolean isLogin = false;
22         do{
23             System.out.println("==================欢迎进入学生管理系统后台=================");
24             System.out.println("账号：");
25             String myuserName = input.next();
26             System.out.println("密码：");
27             String myPassWord = input.next();
28 
29             System.out.println("请输入验证码：");
30             //获取验证码
31             String verificationCode = CodeUtil.genCode();
32             System.out.println("验证码："+verificationCode);
33             String myVerificationCode = input.next();
34 
35             User user = new User();
36             if (user.getUserName().equals(myuserName) &&user.getPassword().equals(myPassWord)
37                     &&verificationCode.equalsIgnoreCase(myVerificationCode)){
38                 //定义10学生的数组
39                 System.out.println("登录成功");
40                 Student[] stu = new Student[10];
41                 boolean isExit = true; //判断是否结束
42 
43                 do {
44                     System.out.println("=====================学生管理系统=====================");
45                     System.out.println("【1】 添加学生");
46                     System.out.println("【2】 修改学生");
47                     System.out.println("【3】 删除学生");
48                     System.out.println("【4】 显示学生");
49                     System.out.println("【5】 分数统计");
50                     System.out.println("【6】 退出系统");
51 
52                     System.out.println("请输入相应功能（序号）：");
53                     int option = input.nextInt();
54                     switch (option) {
55                         case 1:
56                             StuService.addStudent(stu);
57                             break;
58                         case 2:
59                             StuService.updateStudent(stu);
60                             break;
61                         case 3:
62                             StuService.delByStuNo(stu);
63                             break;
64                         case 4:
65                             StuService.printfStuInfo(stu);
66                             break;
67                         case 5:
68                             StuService.printScoreInfo(stu);
69                             break;
70                         case 6:
71                             System.out.println("确认退出吗？(y/n)"); //退出
72                             String optionExit = input.next();
73                             if ("y".equalsIgnoreCase(optionExit)) {
74                                 isExit = false;
75                                 System.out.println("退出");
76                             } else {
77                                 System.out.println("您取消了退出！");
78                             }
79                             break;
80                         default:                                           //输入有误
81                             System.out.println("输入有误，请重新输入[1-6]");
82                     }
83                 } while (isExit);
84             }else {
85                 //账号获密码错误 继续循环 输入密码
86                 isLogin=true;
87             }
88         }while (isLogin);
89 
90     }
91 
92 }

 1 package day04test;
 2 
 3 /**
 4  * @author liuwenlong
 5  * @create 2020-06-30 17:28:35
 6  */
 7 public class Student {
 8     private String stuNo;
 9     private String name;
10     private  int score;
11     private  String pwd;
12 
13     public Student() {
14     }
15 
16     public Student(String stuNo, String name, int score, String pwd) {
17         this.stuNo = stuNo;
18         this.name = name;
19         this.score = score;
20         this.pwd = pwd;
21     }
22 
23     public String getStuNo() {
24         return stuNo;
25     }
26 
27     public void setStuNo(String stuNo) {
28         this.stuNo = stuNo;
29     }
30 
31     public String getName() {
32         return name;
33     }
34 
35     public void setName(String name) {
36         this.name = name;
37     }
38 
39     public int getScore() {
40         return score;
41     }
42 
43     public void setScore(int score) {
44         this.score = score;
45     }
46 
47     public String getPwd() {
48         return pwd;
49     }
50 
51     public void setPwd(String pwd) {
52         this.pwd = pwd;
53     }
54 
55     //打印信息
56     public void showInfo(){
57         System.out.println("学号："+this.stuNo+",姓名："+this.name+",成绩："+this.score);
58     }
59 }

  1 package day04test;
  2 
  3 import day04_2.Stu;
  4 
  5 import java.util.Arrays;
  6 import java.util.Scanner;
  7 
  8 /**
  9  * @author liuwenlong
 10  * @create 2020-06-30 17:27:42
 11  */
 12 public class StuService {
 13     public static Scanner input = new Scanner(System.in);
 14 
 15     /**
 16      * 显示学生信息
 17      */
 18     public static void printStuInfo(Student[] stu) {
 19         System.out.println("序号\t\t学号\t\t名字\t\t分数");
 20         System.out.println("-----------------------------------------------");
 21         for (int j = 0; j < stu.length; j++) {
 22             if (stu[j] == null) {
 23                 continue;
 24             }
 25             System.out.println((j + 1) + "\t\t\t" + stu[j].getStuNo() + "\t\t" + stu[j].getName() + "\t\t" + stu[j].getScore() + "");
 26         }
 27     }
 28 
 29 
 30     /**
 31      * 添加学生
 32      */
 33     public static void addStudent(Student[] stu) {
 34 
 35         System.out.println("=======================添加学生=====================");
 36         System.out.println("请输入学生的学号：");
 37         String myStuNo = input.next();
 38 
 39         System.out.println("请输入学生的姓名：");
 40         String myName = input.next();
 41 
 42         System.out.println("请输入学生的成绩：");
 43         int myScore = input.nextInt();
 44 
 45         System.out.println("请输入学生的密码：");
 46         String myPwd = input.next();
 47 
 48         Student s1 = new Student(myStuNo, myName, myScore, myPwd);
 49         stu[TestStuMgr.i] = s1;
 50         TestStuMgr.i++;
 51     }
 52 
 53 
 54     /**
 55      * 修改学生
 56      */
 57     public static void updateStudent(Student[] stu) {
 58         System.out.println("请输入要修改的学生的学号：");
 59         String myUpdateStuNo = input.next();
 60         for (int k = 0; k < stu.length - 1; k++) {
 61             if (stu[k].getStuNo().equals(myUpdateStuNo)) {
 62                 System.out.println("请重新输入【" + stu[k].getName() + "】同学的成绩：");
 63                 int myUpdateScore = input.nextInt();
 64                 stu[k].setScore(myUpdateScore);
 65 
 66                 System.out.println("请重新输入【" + stu[k].getName() + "】同学的密码：");
 67                 String myUpdatePwd = input.next();
 68                 stu[k].setPwd(myUpdatePwd);
 69                 //修改完毕后直接退出
 70                 return;
 71             }
 72         }
 73     }
 74 
 75 
 76     /**
 77      * 删除学生
 78      */
 79     public static void delByStuNo(Student[] stu) {
 80         System.out.println("------------------------------------------------");
 81         System.out.println("请输入要删除的学号：");
 82         String DelStuNo = input.next(); //要删除的学号
 83 
 84 
 85         for (int k = 0; k < TestStuMgr.i; k++) {
 86             //遍历数组，查找和输入的学号相同的记录下来，然后删除此内容
 87             //定位到当前值，然后从后往前覆盖，最后面的一个给一个空值，然后i-1
 88             if (stu[k].getStuNo().equals(DelStuNo)) {
 89                 int j;
 90                 for (j = k; j < TestStuMgr.i - 1; j++) {
 91                     //后一项赋给前一项，把要删除的那一列覆盖
 92                     stu[j] = stu[(j + 1)];
 93                 }
 94                 stu[TestStuMgr.i - 1] = null;
 95                 TestStuMgr.i--;
 96             }
 97         }
 98         System.out.println("删除成功！");
 99     }
100 
101 
102     /**
103      * 显示学生信息
104      */
105     public static void printfStuInfo(Student[] stu) {
106         //先判断是否为空
107         if (stu !=null&&stu.length>0){
108             System.out.println("序号\t\t学号\t\t名字\t\t分数\t\t名次");
109             System.out.println("--------------------------------------------------------");
110             mySort(stu);//使用自定义排序 进行对数组排序----
111             for (int j = 0; j < TestStuMgr.i; j++) {
112                 if (stu[j] == null) {
113                     continue;
114                 }
115                 System.out.println((j + 1) + "\t\t\t" + stu[j].getStuNo() + "\t\t" + stu[j].getName() + "\t\t" + stu[j].getScore() + "\t\t\t第" + (j + 1) + "名");
116             }
117         }
118 
119     }
120 
121 
122     /**
123      * 分数统计
124      */
125     public static void printScoreInfo(Student[] stu) {
126         int maxScore = stu[0].getScore();
127         int minScore = stu[0].getScore();
128         int sumScore = stu[0].getScore();
129         int maxIndex = 0;
130         int minIndex = 0;
131         double avgScore = 0;  //统计平均分
132         for (int j = 1; j < TestStuMgr.i; j++) {
133             sumScore += stu[j].getScore();
134             if (stu[j].getScore() > maxScore) {
135                 maxScore = stu[j].getScore();
136                 maxIndex = j;
137             }
138             if (stu[j].getScore() < minScore) {
139                 minScore = stu[j].getScore();
140                 minIndex = j;
141             }
142         }
143 
144         avgScore = (sumScore / (TestStuMgr.i));
145         System.out.println("最高分\t\t\t最低分\t\t\t平均分");
146         System.out.println("---------------------------------------------");
147         System.out.println(" " + maxScore + "(" + stu[maxIndex].getName() + ")" + "\t\t" + minScore + "(" + stu[minIndex].getName() + ")" + "\t\t" + avgScore + "\n\n");
148     }
149 
150     //根据分数降序
151     public static void mySort(Student[] stu) {
152         int i, j;
153         Student temp[] = new Student[10];
154         for (i = 0; i < TestStuMgr.i - 1; i++) {
155             for (j = 0; j < TestStuMgr.i - i - 1; j++) {
156                 //使用冒泡对成绩排序
157                 if (stu[j].getScore() < stu[j + 1].getScore()) {
158                     temp[j] = stu[j];
159                     stu[j] = stu[j + 1];
160                     stu[j + 1] = temp[j];
161                 }
162             }
163         }
164     }
165 
166 
167 }

 1 package day04test;
 2 
 3 /**
 4  * 生成验证码
 5  * @author liuwenlong
 6  * @create 2020-06-30 17:27:54
 7  */
 8 public class CodeUtil {
 9     public static String genCode(){
10         char arr[] = new char[4];
11         int i = 0;
12         while (true) {
13             char ch = (char) (int) (Math.random() * 124);
14             if (ch >= 'A' && ch <= 'Z') {
15                 arr[i++] = ch;
16             }
17             if (ch >= 'a' && ch <= 'z') {
18                 arr[i++] = ch;
19             }
20             if (ch >= '0' && ch <= '9') {
21                 arr[i++] = ch;
22             }
23 
24             if (i == 4) {
25                 break;
26             }
27         }
28 
29         //将数组转为字符串
30         String yzm = new String(arr);
31         return yzm;
32     }
33 }

 1 package day04test;
 2 
 3 /**存放用户名和密码
 4  * @author liuwenlong
 5  * @create 2020-06-30 17:28:29
 6  */
 7 public class User {
 8     private String userName="admin";
 9     private String password="admin";
10 
11     public User() {
12     }
13 
14     public User(String userName, String password) {
15         this.userName = userName;
16         this.password = password;
17     }
18 
19     public String getUserName() {
20         return userName;
21     }
22 
23     public void setUserName(String userName) {
24         this.userName = userName;
25     }
26 
27     public String getPassword() {
28         return password;
29     }
30 
31     public void setPassword(String password) {
32         this.password = password;
33     }
34 }