學生成績管理系統
一、程序結構
二、各模塊的功能及程序說明。
關於我的任務部分:定義菜單函數,先打印菜單,再用switch語句給用戶選擇,應用實例化輸入流對象,調用函數完成菜單頁面的打印和選擇;寫一個判斷是否錄入數據的類,通過if語句實現判斷;定義增加函數,通過數組的引用,調用接口實現增加功能;查看即打印功能實現。本軟件採用文件方式寫入,通過對類的封裝來實現格式的整齊,方便查看以及修改,以此提升軟件的清晰性,爲了提升軟件健壯性和可靠性,還使用了throw IOEcxption拋出異常。使用scanner內置的方法next()、nextInt(),接口的直接調用,保證程序的正常運行。
三、源代碼
package class10;
import java.util.Scanner;//導入java輸入流
import java.lang.*;
import java.io.*;
import java.util.ArrayList;
import java.util.Collections;
public class Student implements Comparable<Student> {
private static Student s[] = new Student[1024];
int n = 0;
private String name; // 姓名
private int num; // 學號
private String classAge; // 班級
private double math; // 高等數學
private double english; //大學英語
private double java; // java
private double computer; // 計算機應用基礎
private double aver; // 平均分
private double Max; // 最高分
private double Min; // 最低分
// 判斷是否錄入數據
// throws IOException 這個異常被拋到方法外 在這個方法外被捕獲 拋出異常
//throws IOException表示此方法有拋出IOException異常的可能性
public void judge() throws IOException {
int i;
char ch;
String str;
Scanner In = new Scanner(System.in);
if (n == 0) {
System.out.print("你還沒有錄入任何學生,是否錄入(Y/N):");
str = In.next();
ch = str.charAt(0); // charAt() 方法用於返回指定索引處的字符。索引範圍爲從 0 到 length() - 1。
while (ch != 'Y' && ch != 'y' && ch != 'N' && ch != 'n') {
System.out.print("輸入有誤,請重新輸入:");
str = In.next();
ch = str.charAt(0);
}
if (ch == 'Y' || ch == 'y') {
this.add(); // 增加數據
}
if (ch == 'N' || ch == 'n') {
this.menu();
}
}
}
// 定義菜單函數
public void menu() throws IOException
{
int a;// 定義switch語句變量
Scanner in = new Scanner(System.in); // 實例化輸入流對象
System.out.println("*********學生信息管理系統功能表*********");
System.out.println("***** 1.增加 *****");
System.out.println("***** 2.查看 *****");
System.out.println("***** 3.修改 *****");
System.out.println("***** 4.刪除 *****");
System.out.println("***** 5.顯示 *****");
System.out.println("***** 6.排序 *****");
System.out.println("***** 7.作者 *****");
System.out.println("***** 0.退出 *****");
System.out.println("****************************************");
System.out.print("請選擇(0~7):");
a = in.nextInt();
while (a < 0 || a > 7) {
System.out.print("輸入超出範圍,請重新輸入:");
a = in.nextInt();
}
switch (a) {
case 1:
this.add(); // 增加
break;
case 5:
this.show(); // 顯示即打印
break;
case 3:
this.modif(); // 修改信息
break;
case 4:
this.delete(); // 刪除
break;
case 2:
this.look(); // 查看
break;
case 6:
this.SortANDprint(); // 排序
break;
case 7:
this.writer(); //作者
break;
case 0:
System.exit(0); // 退出
break;
}
}
// 定義增加函數
public void add() throws IOException
{
String str, str1, str2;
int i, num1, t = 1;
char ch, ch1;
FileWriter fw = new FileWriter("C:\\Users\\Lenovo\\Desktop\\C++大法.txt", true);
fw.write(" 錄入的學生信息列表\r\n\r\n學號 姓名 班級 高等數學 大學英語 java課程設計 計算機應用基礎\r\n");
Scanner In = new Scanner(System.in);
while (t == 1) {
System.out.print("請輸入學生學號:");
num1 = In.nextInt();
for (i = 0; i < n; i++) {
while (s[i].num == num1) {
System.out.println("已存在此學號,請重新輸入");
System.out.print("請輸入學號:");
num1 = In.nextInt();
}
}
s[n].num = num1;
str2 = String.valueOf(num1); // 返回參數的字符串表示形式
fw.write(str2 + " "); // 寫入學號
System.out.println();
System.out.print("請輸入學生姓名:");
s[n].name = In.next();
fw.write(s[n].name + " ");
System.out.println();
System.out.print("請輸入學生班級:");
s[n].classAge = In.next();
fw.write(s[n].classAge + " ");
System.out.println();
System.out.print("請輸入學生高等數學成績:");
s[n].math = In.nextDouble();
fw.write(s[n].math + " ");
System.out.println();
System.out.print("請輸入學生大學英語成績:");
s[n].english = In.nextDouble();
fw.write(s[n].english + " ");
System.out.println();
System.out.print("請輸入學生java成績:");
s[n].java = In.nextDouble();
fw.write(s[n].java + " ");
System.out.println();
System.out.print("請輸入學生計算機應用基礎成績:");
s[n].computer = In.nextDouble();
fw.write(s[n].computer + " ");
s[n].aver = (s[n].math + s[n].english + s[n].java + s[n].computer) / 4; // 平均分
fw.write(s[n].aver + " ");
MaxMin(n);
fw.write(s[n].Max + " ");
fw.write(s[n].Min + "\r\n");
++n;
System.out.println();
System.out.print("是否繼續添加(Y/N)");
str = In.next();
ch = str.charAt(0);
while (ch != 'N' && ch != 'n' && ch != 'Y' && ch != 'y') {
System.out.print("輸入有誤,請重新輸入:");
str = In.next();
ch = str.charAt(0);
}
if (ch == 'N' || ch == 'n') {
fw.close();
break;
}
}
System.out.println();
System.out.print("是否返回主菜單(Y/N)");
str1 = In.next();
ch1 = str1.charAt(0);
while (ch1 != 'Y' && ch1 != 'y' && ch1 != 'N' && ch1 != 'n') {
System.out.print("輸入有誤,請重新輸入:");
str1 = In.next();
ch1 = str1.charAt(0);
}
if (ch1 == 'Y' || ch1 == 'y') {
this.menu();
}
if (ch1 == 'N' || ch1 == 'n') {
System.out.println("正在退出...謝謝使用!");
System.exit(0);
}
}
// 查看即打印功能實現
public void look() throws IOException {
int i;
this.judge();
Scanner input = new Scanner(System.in);
System.out.print("請輸入要查看的學號:");
i = input.nextInt();
System.out.println(s[i].toString());
System.out.println("系統返回主菜單!");
this.menu();
}
// 刪除信息功能實現
public void delete() throws IOException
{
this.judge();
int j = 0, t = 0, k = 0, num1;
char ch;
String str;
Scanner pin = new Scanner(System.in);
System.out.print("請輸入要刪除的學號:");
num1 = pin.nextInt();
for (j = 0; j < n; j++) {
if (s[j].num == num1) {
k = 1; // flag 如果找到 k = 1
t = j; // 如果找到將數組下標j給t
}
}
if (k == 0) {
System.out.println("對不起!你要刪除的學號不存在!");
System.out.println("系統將返回主菜單!");
this.menu();
}
if (k == 1) {
System.out.println("你要刪除的學生信息如下:");// 打印管理員要刪除的學生信息
System.out.println(s[t].toString());
System.out.println();
System.out.print("你確定要刪除(Y/N):");
str = pin.next();
ch = str.charAt(0);
while (ch != 'Y' && ch != 'y' && ch != 'N' && ch != 'n') {
System.out.print("輸入有誤,請重新輸入:");
str = pin.next();
ch = str.charAt(0);
}
if (ch == 'N' || ch == 'n') {
System.out.println();
System.out.println("系統返回主菜單!");
this.menu();
}
if (ch == 'Y' || ch == 'y') {
for (j = t; j < n - 1; j++) {
s[j] = s[j + 1]; // 刪除的實現,將數組中後面的元素向前移
}
n--;
System.out.println("數據成功刪除!");
System.out.println("系統返回主菜單!");
this.menu();
}
}
}
public void writer() throws IOException {
System.out.println("張國琛+張澳+文子豪");
}
// 顯示所有數據功能實現
public void show() throws IOException {
FileReader fr = new FileReader("C:\\Users\\Lenovo\\Desktop\\C++大法.txt");
int a;
while ((a = fr.read()) != -1) {
// read()接口 從輸入流讀取數據的下一個字節,返回的字節的值是一個0~255之間的整數。到達流的末尾返回-1。
System.out.print((char) a);
}
fr.close();
System.out.println("系統返回主菜單!");
System.out.println();
this.menu();
}
// 修改數據信息功能
public void modif() throws IOException {
this.judge();
int j = 0, t = 0, k = 0, num2, num3, moi, c = 1;
char ch;
String str, str1, str2;
Double str3, str4, str5, str6;
Scanner pin = new Scanner(System.in);
System.out.print("請輸入要修改的學號:");
num2 = pin.nextInt();
for (j = 0; j < n; j++) {
if (s[j].num == num2) {
k = 1;
t = j;
}
}
if (k == 0) {
System.out.println("對不起!你要修改的學號不存在!");
System.out.println("系統將返回主菜單!");
this.menu();
}
if (k == 1) {
System.out.println("你要修改的學生信息如下:");// 打印管理員要刪除的學生信息
System.out.println(s[t].toString());
System.out.println();
System.out.print("你確定要修改(Y/N):");
str = pin.next();
ch = str.charAt(0);
while (ch != 'Y' && ch != 'y' && ch != 'N' && ch != 'n') {
System.out.print("輸入有誤,請重新輸入:");
str = pin.next();
ch = str.charAt(0);
}
if (ch == 'N' || ch == 'n') {
System.out.println();
System.out.println("系統返回主菜單!");
this.menu();
}
while (c == 1) {
if (ch == 'Y' || ch == 'y') {
System.out.println("****************************************");
System.out.println("***** 1.修改學號 *****");
System.out.println("***** 2.修改班級 *****");
System.out.println("***** 3.修改姓名 *****");
System.out.println("***** 4.修改高等數學 *****");
System.out.println("***** 5.修改大學英語 *****");
System.out.println("***** 6.修改java *****");
System.out.println("***** 7.修改計算機應用基礎 *****");
System.out.println("****************************************");
System.out.print("請選擇:");
moi = pin.nextInt();
switch (moi) {
case 1:
System.out.print("請輸入新的學號:");
num3 = pin.nextInt();
s[t].num = num3;
System.out.println();
break;
case 2:
System.out.print("請輸入新的班級:");
str1 = pin.next();
s[t].classAge = str1;
break;
case 3:
System.out.print("請輸入新的姓名:");
str2 = pin.next();
s[t].name = str2;
break;
case 4:
System.out.print("請輸入新的高等數學成績:");
str3 = pin.nextDouble();
s[t].math = str3;
s[t].aver = (s[t].math + s[t].english + s[t].java + s[t].computer) / 4;
MaxMin(t);
break;
case 5:
System.out.print("請輸入新的大學英語成績:");
str4 = pin.nextDouble();
s[t].english = str4;
s[t].aver = (s[t].math + s[t].english + s[t].java + s[t].computer) / 4;
MaxMin(t);
break;
case 6:
System.out.print("請輸入新的java成績:");
str5 = pin.nextDouble();
s[t].java = str5;
s[t].aver = (s[t].math + s[t].english + s[t].java + s[t].computer) / 4;
MaxMin(t);
break;
case 7:
System.out.print("請輸入新的計算機應用基礎成績:");
str6 = pin.nextDouble();
s[t].computer = str6;
s[t].aver = (s[t].math + s[t].english + s[t].java + s[t].computer) / 4;
MaxMin(t);
break;
}
System.out.println("數據已成功修改!");
}
System.out.print("是否繼續修改(Y/N)");
str = pin.next();
ch = str.charAt(0);
System.out.println();
while (ch != 'Y' && ch != 'y' && ch != 'N' && ch != 'n') {
System.out.print("輸入有誤,請重新輸入:");
str = pin.next();
ch = str.charAt(0);
}
if (ch == 'N' || ch == 'n') {
break;
}
}
}
System.out.println();
System.out.println("系統返回主菜單!");
this.menu();
}
// 最高分最低分實現
public void MaxMin(int i) {
s[i].Max = s[i].math;
if(s[i].english > s[i].math) {
s[i].Max = s[i].english;
}
else if(s[i].java > s[i].math || s[i].java > s[i].english) {
s[i].Max = s[i].java;
}
else if(s[i].computer > s[i].math || s[i].computer > s[i].english || s[i].computer > s[i].java) {
s[i].Max = s[i].computer;
}
s[i].Min = s[i].math;
if(s[i].english < s[i].math) {
s[i].Min = s[i].english;
}
else if(s[i].java < s[i].math || s[i].java < s[i].english) {
s[i].Min = s[i].java;
}
else if(s[i].computer < s[i].math || s[i].computer < s[i].english || s[i].computer < s[i].java) {
s[i].Min = s[i].computer;
}
}
//求平均值
public String toString() {
return "Student [num =" + num + ", name =" + name + ", classAge = "
+ classAge + ", math = " + math + ", english = "
+ english + ", computer = " + computer + ", Java = "
+ java + ", aver = " + aver+ '\n' + "]";
}
// 排序方法
public void SortANDprint() throws IOException {
ArrayList<Student> Students = new ArrayList<>();
int i = 0;
for(i = 0; i < n; i++)
{
Students.add(s[i]);
}
Collections.sort(Students);
FileWriter fw = new FileWriter("C:\\Users\\Lenovo\\Desktop\\C++大法.txt", false);
for (Student s : Students) {
fw.write(s.toString());
System.out.println(s.toString());
}
fw.close();
menu();
}
// 重寫
public int compareTo(Student o) {
return (int)(o.aver - this.aver);
}
// main 函數
public static void main(String[] args) throws IOException {
Student stu = new Student();
for (int i = 0; i < 1024; i++) {
s[i] = new Student();
}
stu.menu();
}
}
四、運行結果演示