java《学生成绩管理系统》功能介绍以及代码实现
学生成绩管理系统
一、程序结构
二、各模块的功能及程序说明。
关于我的任务部分：定义菜单函数，先打印菜单，再用switch语句给用户选择，应用实例化输入流对象，调用函数完成菜单页面的打印和选择；写一个判断是否录入数据的类，通过if语句实现判断；定义增加函数，通过数组的引用，调用接口实现增加功能；查看即打印功能实现。本软件采用文件方式写入，通过对类的封装来实现格式的整齐，方便查看以及修改，以此提升软件的清晰性，为了提升软件健壮性和可靠性，还使用了throw IOEcxption抛出异常。使用scanner内置的方法next()、nextInt()，接口的直接调用，保证程序的正常运行。
三、源代码
package class10;
import java.util.Scanner;//导入java输入流
import java.lang.*;
import java.io.*;
import java.util.ArrayList;
import java.util.Collections;
public class Student implements Comparable {
private static Student s[] = new Student[1024];
int n = 0;
private String name; // 姓名
private int num; // 学号
private String classAge; // 班级
private double math; // 高等数学
private double english; //大学英语
private double java; // java
private double computer; // 计算机应用基础
private double aver; // 平均分
private double Max; // 最高分
private double Min; // 最低分
// 判断是否录入数据
// throws IOException 这个异常被抛到方法外 在这个方法外被捕获 抛出异常
//throws IOException表示此方法有抛出IOException异常的可能性
public void judge() throws IOException {
int i;
char ch;
String str;
Scanner In = new Scanner(System.in);
if (n == 0) {
System.out.print("你还没有录入任何学生，是否录入(Y/N):");
str = In.next();
ch = str.charAt(0); // charAt() 方法用于返回指定索引处的字符。索引范围为从 0 到 length() - 1。
while (ch != 'Y' && ch != 'y' && ch != 'N' && ch != 'n') {
System.out.print("输入有误，请重新输入:");
str = In.next();
ch = str.charAt(0);
}
if (ch == 'Y' || ch == 'y') {
this.add(); // 增加数据
}
if (ch == 'N' || ch == 'n') {
this.menu();
}
}
}
// 定义菜单函数
public void menu() throws IOException
{
int a;// 定义switch语句变量
Scanner in = new Scanner(System.in); // 实例化输入流对象
System.out.println("*********学生信息管理系统功能表*********");
System.out.println("***** 1.增加 *****");
System.out.println("***** 2.查看 *****");
System.out.println("***** 3.修改 *****");
System.out.println("***** 4.删除 *****");
System.out.println("***** 5.显示 *****");
System.out.println("***** 6.排序 *****");
System.out.println("***** 7.作者 *****");
System.out.println("***** 0.退出 *****");
System.out.println("****************************************");
System.out.print("请选择(0~7):");
a = in.nextInt();
while (a < 0 || a > 7) {
System.out.print("输入超出范围，请重新输入:");
a = in.nextInt();
}
switch (a) {
case 1:
this.add(); // 增加
break;
case 5:
this.show(); // 显示即打印
break;
case 3:
this.modif(); // 修改信息
break;
case 4:
this.delete(); // 删除
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;
}
}
// 定义增加函数
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(" 录入的学生信息列表\r\n\r\n学号 姓名 班级 高等数学 大学英语 java课程设计 计算机应用基础\r\n");
Scanner In = new Scanner(System.in);
while (t == 1) {
System.out.print("请输入学生学号:");
num1 = In.nextInt();
for (i = 0; i < n; i++) {
while (s[i].num == num1) {
System.out.println("已存在此学号，请重新输入");
System.out.print("请输入学号:");
num1 = In.nextInt();
}
}
s[n].num = num1;
str2 = String.valueOf(num1); // 返回参数的字符串表示形式
fw.write(str2 + " "); // 写入学号
System.out.println();
System.out.print("请输入学生姓名:");
s[n].name = In.next();
fw.write(s[n].name + " ");
System.out.println();
System.out.print("请输入学生班级:");
s[n].classAge = In.next();
fw.write(s[n].classAge + " ");
System.out.println();
System.out.print("请输入学生高等数学成绩:");
s[n].math = In.nextDouble();
fw.write(s[n].math + " ");
System.out.println();
System.out.print("请输入学生大学英语成绩:");
s[n].english = In.nextDouble();
fw.write(s[n].english + " ");
System.out.println();
System.out.print("请输入学生java成绩:");
s[n].java = In.nextDouble();
fw.write(s[n].java + " ");
System.out.println();
System.out.print("请输入学生计算机应用基础成绩:");
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("是否继续添加(Y/N)");
str = In.next();
ch = str.charAt(0);
while (ch != 'N' && ch != 'n' && ch != 'Y' && ch != 'y') {
System.out.print("输入有误，请重新输入:");
str = In.next();
ch = str.charAt(0);
}
if (ch == 'N' || ch == 'n') {
fw.close();
break;
}
}
System.out.println();
System.out.print("是否返回主菜单(Y/N)");
str1 = In.next();
ch1 = str1.charAt(0);
while (ch1 != 'Y' && ch1 != 'y' && ch1 != 'N' && ch1 != 'n') {
System.out.print("输入有误，请重新输入:");
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...谢谢使用!");
System.exit(0);
}
}
// 查看即打印功能实现
public void look() throws IOException {
int i;
this.judge();
Scanner input = new Scanner(System.in);
System.out.print("请输入要查看的学号:");
i = input.nextInt();
System.out.println(s[i].toString());
System.out.println("系统返回主菜单!");
this.menu();
}
// 删除信息功能实现
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("请输入要删除的学号:");
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; // 如果找到将数组下标j给t
}
}
if (k == 0) {
System.out.println("对不起！你要删除的学号不存在！");
System.out.println("系统将返回主菜单！");
this.menu();
}
if (k == 1) {
System.out.println("你要删除的学生信息如下:");// 打印管理员要删除的学生信息
System.out.println(s[t].toString());
System.out.println();
System.out.print("你确定要删除(Y/N):");
str = pin.next();
ch = str.charAt(0);
while (ch != 'Y' && ch != 'y' && ch != 'N' && ch != 'n') {
System.out.print("输入有误，请重新输入:");
str = pin.next();
ch = str.charAt(0);
}
if (ch == 'N' || ch == 'n') {
System.out.println();
System.out.println("系统返回主菜单！");
this.menu();
}
if (ch == 'Y' || ch == 'y') {
for (j = t; j < n - 1; j++) {
s[j] = s[j + 1]; // 删除的实现，将数组中后面的元素向前移
}
n--;
System.out.println("数据成功删除!");
System.out.println("系统返回主菜单!");
this.menu();
}
}
}
public void writer() throws IOException {
System.out.println("张国琛+张澳+文子豪");
}
// 显示所有数据功能实现
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 从输入流读取数据的下一个字节，返回的字节的值是一个0~255之间的整数。到达流的末尾返回-1。
System.out.print((char) a);
}
fr.close();
System.out.println("系统返回主菜单！");
System.out.println();
this.menu();
}
// 修改数据信息功能
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("请输入要修改的学号:");
num2 = pin.nextInt();
for (j = 0; j < n; j++) {
if (s[j].num == num2) {
k = 1;
t = j;
}
}
if (k == 0) {
System.out.println("对不起！你要修改的学号不存在！");
System.out.println("系统将返回主菜单！");
this.menu();
}
if (k == 1) {
System.out.println("你要修改的学生信息如下:");// 打印管理员要删除的学生信息
System.out.println(s[t].toString());
System.out.println();
System.out.print("你确定要修改(Y/N):");
str = pin.next();
ch = str.charAt(0);
while (ch != 'Y' && ch != 'y' && ch != 'N' && ch != 'n') {
System.out.print("输入有误，请重新输入:");
str = pin.next();
ch = str.charAt(0);
}
if (ch == 'N' || ch == 'n') {
System.out.println();
System.out.println("系统返回主菜单！");
this.menu();
}
while (c == 1) {
if (ch == 'Y' || ch == 'y') {
System.out.println("****************************************");
System.out.println("***** 1.修改学号 *****");
System.out.println("***** 2.修改班级 *****");
System.out.println("***** 3.修改姓名 *****");
System.out.println("***** 4.修改高等数学 *****");
System.out.println("***** 5.修改大学英语 *****");
System.out.println("***** 6.修改java *****");
System.out.println("***** 7.修改计算机应用基础 *****");
System.out.println("****************************************");
System.out.print("请选择:");
moi = pin.nextInt();
switch (moi) {
case 1:
System.out.print("请输入新的学号:");
num3 = pin.nextInt();
s[t].num = num3;
System.out.println();
break;
case 2:
System.out.print("请输入新的班级:");
str1 = pin.next();
s[t].classAge = str1;
break;
case 3:
System.out.print("请输入新的姓名:");
str2 = pin.next();
s[t].name = str2;
break;
case 4:
System.out.print("请输入新的高等数学成绩:");
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("请输入新的大学英语成绩:");
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("请输入新的java成绩:");
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("请输入新的计算机应用基础成绩:");
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("数据已成功修改！");
}
System.out.print("是否继续修改(Y/N)");
str = pin.next();
ch = str.charAt(0);
System.out.println();
while (ch != 'Y' && ch != 'y' && ch != 'N' && ch != 'n') {
System.out.print("输入有误，请重新输入:");
str = pin.next();
ch = str.charAt(0);
}
if (ch == 'N' || ch == 'n') {
break;
}
}
}
System.out.println();
System.out.println("系统返回主菜单！");
this.menu();
}
// 最高分最低分实现
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 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();
}
// 重写
public int compareTo(Student o) {
return (int)(o.aver - this.aver);
}
// main 函数
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、运行结果演示
