java学生管理系统，使用文件存储数据。初始版
1、student类，以字符形式储存数据。
public class student {
String code;
String name;
String sex;
String age;
String scoreChinese;
String scoreMath;
String scoreEnglish;
}2、 Main类，初始化对象，打开menu界面。
class Main {
public static void main(String[] args) throws IOException {
//建立学生管理系统
Manage m1 = new Manage();
m1.readFile();
while (m1.flag) {
m1.menu();
}
System.out.println("您已经退出系统");
}
}3、Judge类，对输入的数据格式进行判断。
class Judge {//判断学生数量
static boolean judgeNum(String str) {
char[] ch = str.toCharArray();
for (int i = 0; i < ch.length; i++) {
if (ch[i] < 48 | ch[i] > 57)
return false;
}
if (Integer.parseInt(str) < 0 | Integer.parseInt(str) > Manage.N - Manage.n)
return false;
return true;
}
static boolean judgeCode(String str) {
char[] ch = str.toCharArray();
for (int i = 0; i < ch.length; i++) {
if (ch[i] < 48 | ch[i] > 57) {
return false;
}
}
for (int i = 0; i < Manage.n; i++) {
if (str.equals(Manage.getCode(i)))
return false;
}
return true;
}
static boolean judgeAge(String str) {//判断年龄
char[] ch = str.toCharArray();
for (int i = 0; i < ch.length; i++) {
if (ch[i] < 48 | ch[i] > 57) {
return false;
}
}
if (Integer.parseInt(str) < 0 | Integer.parseInt(str) > 100)
return false;
return true;
}
static boolean judgeScore(String str) {//判断分数
char[] ch = str.toCharArray();
if (ch[0] == 46)
return false;
for (int i = 0; i < ch.length; i++) {
if (ch[i] != 46) {
if (ch[i] < 48 | ch[i] > 57)
return false;
}
}
return true;
}
static boolean judgeSex(String str) {//判断性别
if (str.equals("F") | str.equals("f") | str.equals("M") | str.equals("m"))
return true;
return false;
}
}4、功能类，提供主要功能
void meau()；菜单功能，用户可以选择一项进行操作。
void help()；帮助菜单，为用户提供简单的使用方法。
void insert()；插入学生信息，并将学生信息存入文档。
void modify()；修改学生信息，并将学生信息存入文档。
void display()；显示功能，显示当前已有学生的信息。
void del()；删除功能，按照学号或者姓名可以删除，若姓名相等，则删 除学号靠前的学生信息。
void seek()；查找功能。
void sort()；排序工能，将学生对象排序，并按学号升序重新将信息写入文件。
void readFile()；读档功能，读取已有学生的信息。
TIPS: 本人能力有限，对文件操作不够了解故在文件读取函数中采用了清空原有文件数据，简化操作，如需更改请更改void readFile()；
class Manage {
boolean flag = true;//运行开始或者结束标志变量
static int N = 100;
static student[] stu = new student[N];
static int n = 0;
int m = 0;
Scanner sc = new Scanner(System.in);
void menu() throws IOException {
String num;
System.out.println("*************************************************");
System.out.println(" * 学生管理系统 *");
System.out.println(" * 系统功能菜单 *");
System.out.println("*************************************************");
System.out.println("0.系统帮助及说明 1.刷新学生信息");
System.out.println("2.查询学生信息 3.修改学生信息");
System.out.println("4.增加学生信息 5.按学号删除信息");
System.out.println("6.显示当前信息 7.保存当前学生信息");
System.out.println("8.退出系统");
System.out.println("*************************************************");
System.out.println("请选择菜单编号：");
num = sc.next();
switch (num) {
case "0":
help();
break;
case "2":
seek();
break;
case "3":
modify();
break;
case "4":
insert();
break;
case "5":
del();
break;
case "6":
display();
break;
case "8":
flag = false;
sc.close();
break;
default:
System.out.println("请重新在 0--8 之间选择");
}
}
void help() {
System.out.println("0.欢迎进入系统帮助界面！");
System.out.println("1.初次进入系统后，请选择增加学生信息；");
System.out.println("2.按照菜单提示键入数字代号；");
System.out.println("3.增加学生信息后，切记保存；");
System.out.println("4.注意！本系统仅能对输入信息进行更改保存，打开系统会初始化原数据文件内容");
System.out.println("5.谢谢您的使用！");
}
void insert() throws IOException {
int j = n;
System.out.print("请输入待增加学生数；");
String str = sc.next();
if (!Judge.judgeNum(str)) {
System.out.println("输入数据有误请重新输入");
return;
}
m = Integer.parseInt(str);
for (int i = j; i < j + m; i++) {
stu[i] = new student();
}
do { //输入学号判断
System.out.println("请输入第" + (j - n + 1) + "个学生的学号");
stu[j].code = sc.next();
if (!Judge.judgeCode(stu[j].code)) {
System.out.println("输入有误或者学号已存在，请重新输入该学生信息");
continue;
}
System.out.println("请输入第" + (j - n + 1) + "个学生的姓名");
stu[j].name = sc.next();
System.out.println("请输入第" + (j - n + 1) + "个学生的年龄");
stu[j].age = sc.next();
if (!Judge.judgeAge(stu[j].age)) {
System.out.println("输入有误，请重新输入该学生的信息");
continue;
}
System.out.println("请输入第" + (j - n + 1) + "个学生的性别，男生使用F/f,女生使用M/m");
stu[j].sex = sc.next();
if (!Judge.judgeSex(stu[j].sex)) {
System.out.println("输入有误，请重新输入该学生的信息");
continue;
}
System.out.println("请输入第" + (j - n + 1) + "个学生的语文成绩");
stu[j].scoreChinese = sc.next();
if (!Judge.judgeScore(stu[j].scoreChinese)) {
System.out.println("输入有误，请重新输入该学生的信息");
continue;
}
System.out.println("请输入第" + (j - n + 1) + "个学生的英语成绩");
stu[j].scoreEnglish = sc.next();
if (!Judge.judgeScore(stu[j].scoreEnglish)) {
System.out.println("输入有误，请重新输入该学生的信息");
continue;
}
System.out.println("请输入第" + (j - n + 1) + "个学生的数学成绩");
stu[j].scoreMath = sc.next();
if (!Judge.judgeScore(stu[j].scoreMath)) {
System.out.println("输入有误，请重新输入该学生的信息");
continue;
}
//将信息存入文档
FileWriter fw = new FileWriter("student.txt", true);
String strTemp = (stu[j].code + " " + stu[j].name + " "
+ stu[j].age + " " + stu[j].sex + " " + stu[j].scoreChinese + " " +
stu[j].scoreEnglish + " " + stu[j].scoreMath + " \r\n");
fw.write(strTemp);
fw.close();
j++;
} while (j < n + m);
n += m;
System.out.println("信息添加成功！");
sort();//按学号升序进行排列
}
void modify() throws IOException {
boolean flag = true;
System.out.print("请输入要修改的学生学号：");
String str = sc.next();
int t;//修改学生的学生下标数值
//需要修改的学生字符数据
for (int i = 0; i < n; i++) {
if (stu[i].code.equals(str)) {
if (stu[i].code.equals(str)) {//定义str储存修改前学生的信息
t = i;
String dataOldStudent = (stu[t].code + " " + stu[t].name + " "
+ stu[t].age + " " + stu[t].sex + " " + stu[t].scoreChinese + " " +
stu[t].scoreEnglish + " " + stu[t].scoreMath + " \r\n");
flag = false;
System.out.println("---------------------------------");
System.out.println("1.修改姓名");
System.out.println("2.修改年龄");
System.out.println("3.修改性别");
System.out.println("4.修改语文成绩");
System.out.println("5.修改英语成绩");
System.out.println("6.修改数学成绩");
System.out.println("7.保存修改信息并退出本菜单");
System.out.println("---------------------------------");
while (true) {
System.out.println("请选择子菜单代号");
String item = sc.next();
switch (item) {
case "1":
System.out.println("请输入新的名字：");
stu[i].name = sc.next();
break;
case "2":
System.out.println("请输入新的年龄：");
stu[i].age = sc.next();
if (!Judge.judgeAge(stu[i].age)) {
System.out.println("输入有误，请重新输入该学生的信息");
}
break;
case "3":
System.out.println("请输入新的性别：");
stu[i].sex = sc.next();
break;
case "4":
System.out.println("请输入新的语文成绩：");
stu[i].scoreChinese = sc.next();
if (!Judge.judgeScore(stu[i].scoreChinese)) {
System.out.println("输入有误，请重新输入该学生的信息");
}
break;
case "5":
System.out.println("请输入新的英语成绩：");
stu[i].scoreEnglish = sc.next();
if (!Judge.judgeScore(stu[i].scoreEnglish)) {
System.out.println("输入有误，请重新输入该学生的信息");
}
break;
case "6":
System.out.println("请输入新的数学成绩：");
stu[i].scoreMath = sc.next();
if (!Judge.judgeScore(stu[i].scoreMath)) {
System.out.println("输入有误，请重新输入该学生的信息");
}
break;
case "7":
if (!flag) {
String dataNewStudent = (stu[t].code + " " + stu[t].name + " "
+ stu[t].age + " " + stu[t].sex + " " + stu[t].scoreChinese + " " +
stu[t].scoreEnglish + " " + stu[t].scoreMath + " ");
File f = new File("Student.txt");
long length = f.length();
FileReader fr = new FileReader("Student.txt");
char[] ch = new char[(int) length];
fr.read(ch);
fr.close();
String str1 = new String(ch);
str1 = str1.replace(dataOldStudent, dataNewStudent); //进行修改操作
FileWriter fw = new FileWriter("student.txt");//将新字符串写进文件
fw.write(str1);
fw.close();
}
return;
default:
System.out.println("请在 1--7 之间选择");
}
}
}
}
}
if (flag)
System.out.println("该学生不在系统中");
}
void display() {
System.out.println("共有" + n + "位学生信息；");
if (n != 0) {
System.out.println("学生学号 学生姓名 年龄 性别 语文成绩 英语成绩 数学成绩 ");
System.out.println("---------------------------------------------------------------------------------");
for (int i = 0; i < n; i++) {
System.out.println(stu[i].code + " \t\t\t\t\t" + stu[i].name + " \t\t\t"
+ stu[i].age + " \t\t" + stu[i].sex + " \t\t" + stu[i].scoreChinese + " \t\t" +
stu[i].scoreEnglish + " \t\t" + stu[i].scoreMath);
}
}
}
void del() throws IOException {
System.out.println("请输入要删除学生的学号：");
String code = sc.next();
boolean flag = false;
for (int i = 0; i < n; i++) {
if (stu[i].code.equals(code)) {
flag = true;
String dataStudent = (stu[i].code + " " + stu[i].name + " "
+ stu[i].age + " " + stu[i].sex + " " + stu[i].scoreChinese + " " +
stu[i].scoreEnglish + " " + stu[i].scoreMath);
if (i == n - 1) {//删除最后一个同学
stu[i] = null;
n -= 1;
} else {//删除的不是最后一个同学
for (int j = 1; i < n; j++) {
stu[j] = stu[j + 1];
}
stu[n - 1] = null;
n -= 1;
}
File f = new File("student.txt");
long length = f.length();
FileReader fr = new FileReader("student.txt");
char[] ch = new char[(int) length];
fr.read(ch);
fr.close();
String str = new String(ch);
str = str.replace(dataStudent, " ");//删除操作
FileWriter fw = new FileWriter("student.txt");//写入新文件
fw.write(str);
fw.close();
}
}
if (flag == false)
System.out.println("该学号不存在！");
if (flag == true)
System.out.println("删除成功");
}
void seek() {//查找算法
int i;
String item, code, name;
boolean flag = false;
System.out.println("---------------------------------------------");
System.out.println("1.按学号查询");
System.out.println("2.按姓名查询");
System.out.println("3.退出本菜单");
System.out.println("---------------------------------------------");
while (true) {
System.out.println("请选择子菜单编号：");
item = sc.next();
flag = false;
switch (item) {
case "1":
System.out.println("请输入要查询的学生的学号：");
code = sc.next();
for (i = 0; i < n; i++)
if (stu[i].code.equals(code)) {
flag = true;
System.out.println("学生学号 学生姓名 年龄 性别 语文成绩 英语成绩 数学成绩 ");
System.out.println("---------------------------------------------------------------------------------");
System.out.println(stu[i].code + " \t\t\t\t\t" + stu[i].name + " \t\t"
+ stu[i].age + " \t\t" + stu[i].sex + " \t\t" + stu[i].scoreChinese + " \t\t" +
stu[i].scoreEnglish + " \t\t" + stu[i].scoreMath);
}
if (false == flag)
System.out.println("该学号不存在！");
break;
case "2":
System.out.println("请输入要查询的学生的姓名：");
name = sc.next();
for (i = 0; i < n; i++)
if (stu[i].name.equals(name)) {
flag = true;
System.out.println("学生学号 学生姓名 年龄 性别 语文成绩 英语成绩 数学成绩 ");
System.out.println("---------------------------------------------------------------------------------");
System.out.println(stu[i].code + " \t\t\t\t\t" + stu[i].name + " \t\t"
+ stu[i].age + " \t\t" + stu[i].sex + " \t\t" + stu[i].scoreChinese + " \t\t" +
stu[i].scoreEnglish + " \t\t" + stu[i].scoreMath);
}
if (false == flag)
System.out.println("该姓名不存在！");
break;
case "3":
return;
default:
System.out.println("请在 1--3 之间选择");
}
}
}
static String getCode(int i) {//Judge类中使用
return stu[i].code;
}
void sort() throws IOException {
int[] code = new int[n];
int temp;
student stuTemp = new student();
for (int i = 0; i < n; i++) {
code[i] = Integer.parseInt(stu[i].code);
}
for (int i = 0; i < n - 1; i++) {//使用选择排序法对学生对象进行排序
for (int j = i + 1; j < n; j++) {
if (code[i] > code[j]) {
temp = code[i];
code[i] = code[j];
code[j] = temp;
stuTemp = stu[i];
stu[i] = stu[j];
stu[j] = stuTemp;
}
}
}
FileWriter fw = new FileWriter("student.txt");//按学号顺序将学生信息写入文件
for (int i = 0; i < n; i++) {
String strTemp = (stu[i].code + " " + stu[i].name + " "
+ stu[i].age + " " + stu[i].sex + " " + stu[i].scoreChinese + " " +
stu[i].scoreEnglish + " " + stu[i].scoreMath + " \r\n");
fw.write(strTemp);
}
fw.close();
}
void readFile() throws IOException {
File f = new File("student.txt");
try {
if (!f.exists()) {
f.createNewFile();
}
FileWriter fileWriter = new FileWriter(f);//打开文件清空文件原有内容
fileWriter.write("");
fileWriter.flush();
fileWriter.close();
} catch (IOException e) {
e.printStackTrace();
}
int length = (int) f.length();
if (length == 0)
return;
FileReader fr = new FileReader("student.txt");
char[] ch = new char[length];
fr.read(ch);
fr.close();
String str = new String(ch);
//将字符串分割成数组并初始化
String regex1 = "\\s{2}";
String regex2 = "\\p{Blank}";
String[] strArray = str.split(regex1);
n = strArray.length;
for (int i = 0; i < n; i++) {
stu[i] = new student();
}
//初始化对象
for (int i = 0; i < strArray.length; i++) {
String[] strArray2 = strArray[i].split(regex2);
stu[i].code = strArray2[0];
stu[i].name = strArray2[1];
stu[i].age = strArray2[2];
stu[i].sex = strArray2[3];
stu[i].scoreChinese = strArray2[4];
stu[i].scoreEnglish = strArray2[5];
stu[i].scoreMath = strArray2[6];
}
}
}源代码：
import java.io.File; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; import java.util.Scanner; public class student { String code; String name; String sex; String age; String scoreChinese; String scoreMath; String scoreEnglish; } class Main { public static void main(String[] args) throws IOException { //建立学生管理系统 Manage m1 = new Manage(); m1.readFile(); while (m1.flag) { m1.menu(); } System.out.println("您已经退出系统"); } } class Judge {//判断学生数量 static boolean judgeNum(String str) { char[] ch = str.toCharArray(); for (int i = 0; i < ch.length; i++) { if (ch[i] < 48 | ch[i] > 57) return false; } if (Integer.parseInt(str) < 0 | Integer.parseInt(str) > Manage.N - Manage.n) return false; return true; } static boolean judgeCode(String str) { char[] ch = str.toCharArray(); for (int i = 0; i < ch.length; i++) { if (ch[i] < 48 | ch[i] > 57) { return false; } } for (int i = 0; i < Manage.n; i++) { if (str.equals(Manage.getCode(i))) return false; } return true; } static boolean judgeAge(String str) {//判断年龄 char[] ch = str.toCharArray(); for (int i = 0; i < ch.length; i++) { if (ch[i] < 48 | ch[i] > 57) { return false; } } if (Integer.parseInt(str) < 0 | Integer.parseInt(str) > 100) return false; return true; } static boolean judgeScore(String str) {//判断分数 char[] ch = str.toCharArray(); if (ch[0] == 46) return false; for (int i = 0; i < ch.length; i++) { if (ch[i] != 46) { if (ch[i] < 48 | ch[i] > 57) return false; } } return true; } static boolean judgeSex(String str) {//判断性别 if (str.equals("F") | str.equals("f") | str.equals("M") | str.equals("m")) return true; return false; } } class Manage { boolean flag = true;//运行开始或者结束标志变量 static int N = 100; static student[] stu = new student[N]; static int n = 0; int m = 0; Scanner sc = new Scanner(System.in); void menu() throws IOException { String num; System.out.println("*************************************************"); System.out.println(" * 学生管理系统 *"); System.out.println(" * 系统功能菜单 *"); System.out.println("*************************************************"); System.out.println("0.系统帮助及说明 1.刷新学生信息"); System.out.println("2.查询学生信息 3.修改学生信息"); System.out.println("4.增加学生信息 5.按学号删除信息"); System.out.println("6.显示当前信息 7.保存当前学生信息"); System.out.println("8.退出系统"); System.out.println("*************************************************"); System.out.println("请选择菜单编号："); num = sc.next(); switch (num) { case "0": help(); break; case "2": seek(); break; case "3": modify(); break; case "4": insert(); break; case "5": del(); break; case "6": display(); break; case "8": flag = false; sc.close(); break; default: System.out.println("请重新在 0--8 之间选择"); } } void help() { System.out.println("0.欢迎进入系统帮助界面！"); System.out.println("1.初次进入系统后，请选择增加学生信息；"); System.out.println("2.按照菜单提示键入数字代号；"); System.out.println("3.增加学生信息后，切记保存；"); System.out.println("4.注意！本系统仅能对输入信息进行更改保存，打开系统会初始化原数据文件内容"); System.out.println("5.谢谢您的使用！"); } void insert() throws IOException { int j = n; System.out.print("请输入待增加学生数；"); String str = sc.next(); if (!Judge.judgeNum(str)) { System.out.println("输入数据有误请重新输入"); return; } m = Integer.parseInt(str); for (int i = j; i < j + m; i++) { stu[i] = new student(); } do { //输入学号判断 System.out.println("请输入第" + (j - n + 1) + "个学生的学号"); stu[j].code = sc.next(); if (!Judge.judgeCode(stu[j].code)) { System.out.println("输入有误或者学号已存在，请重新输入该学生信息"); continue; } System.out.println("请输入第" + (j - n + 1) + "个学生的姓名"); stu[j].name = sc.next(); System.out.println("请输入第" + (j - n + 1) + "个学生的年龄"); stu[j].age = sc.next(); if (!Judge.judgeAge(stu[j].age)) { System.out.println("输入有误，请重新输入该学生的信息"); continue; } System.out.println("请输入第" + (j - n + 1) + "个学生的性别，男生使用F/f,女生使用M/m"); stu[j].sex = sc.next(); if (!Judge.judgeSex(stu[j].sex)) { System.out.println("输入有误，请重新输入该学生的信息"); continue; } System.out.println("请输入第" + (j - n + 1) + "个学生的语文成绩"); stu[j].scoreChinese = sc.next(); if (!Judge.judgeScore(stu[j].scoreChinese)) { System.out.println("输入有误，请重新输入该学生的信息"); continue; } System.out.println("请输入第" + (j - n + 1) + "个学生的英语成绩"); stu[j].scoreEnglish = sc.next(); if (!Judge.judgeScore(stu[j].scoreEnglish)) { System.out.println("输入有误，请重新输入该学生的信息"); continue; } System.out.println("请输入第" + (j - n + 1) + "个学生的数学成绩"); stu[j].scoreMath = sc.next(); if (!Judge.judgeScore(stu[j].scoreMath)) { System.out.println("输入有误，请重新输入该学生的信息"); continue; } //将信息存入文档 FileWriter fw = new FileWriter("student.txt", true); String strTemp = (stu[j].code + " " + stu[j].name + " " + stu[j].age + " " + stu[j].sex + " " + stu[j].scoreChinese + " " + stu[j].scoreEnglish + " " + stu[j].scoreMath + " \r\n"); fw.write(strTemp); fw.close(); j++; } while (j < n + m); n += m; System.out.println("信息添加成功！"); sort();//按学号升序进行排列 } void modify() throws IOException { boolean flag = true; System.out.print("请输入要修改的学生学号："); String str = sc.next(); int t;//修改学生的学生下标数值 //需要修改的学生字符数据 for (int i = 0; i < n; i++) { if (stu[i].code.equals(str)) { if (stu[i].code.equals(str)) {//定义str储存修改前学生的信息 t = i; String dataOldStudent = (stu[t].code + " " + stu[t].name + " " + stu[t].age + " " + stu[t].sex + " " + stu[t].scoreChinese + " " + stu[t].scoreEnglish + " " + stu[t].scoreMath + " \r\n"); flag = false; System.out.println("---------------------------------"); System.out.println("1.修改姓名"); System.out.println("2.修改年龄"); System.out.println("3.修改性别"); System.out.println("4.修改语文成绩"); System.out.println("5.修改英语成绩"); System.out.println("6.修改数学成绩"); System.out.println("7.保存修改信息并退出本菜单"); System.out.println("---------------------------------"); while (true) { System.out.println("请选择子菜单代号"); String item = sc.next(); switch (item) { case "1": System.out.println("请输入新的名字："); stu[i].name = sc.next(); break; case "2": System.out.println("请输入新的年龄："); stu[i].age = sc.next(); if (!Judge.judgeAge(stu[i].age)) { System.out.println("输入有误，请重新输入该学生的信息"); } break; case "3": System.out.println("请输入新的性别："); stu[i].sex = sc.next(); break; case "4": System.out.println("请输入新的语文成绩："); stu[i].scoreChinese = sc.next(); if (!Judge.judgeScore(stu[i].scoreChinese)) { System.out.println("输入有误，请重新输入该学生的信息"); } break; case "5": System.out.println("请输入新的英语成绩："); stu[i].scoreEnglish = sc.next(); if (!Judge.judgeScore(stu[i].scoreEnglish)) { System.out.println("输入有误，请重新输入该学生的信息"); } break; case "6": System.out.println("请输入新的数学成绩："); stu[i].scoreMath = sc.next(); if (!Judge.judgeScore(stu[i].scoreMath)) { System.out.println("输入有误，请重新输入该学生的信息"); } break; case "7": if (!flag) { String dataNewStudent = (stu[t].code + " " + stu[t].name + " " + stu[t].age + " " + stu[t].sex + " " + stu[t].scoreChinese + " " + stu[t].scoreEnglish + " " + stu[t].scoreMath + " "); File f = new File("Student.txt"); long length = f.length(); FileReader fr = new FileReader("Student.txt"); char[] ch = new char[(int) length]; fr.read(ch); fr.close(); String str1 = new String(ch); str1 = str1.replace(dataOldStudent, dataNewStudent); //进行修改操作 FileWriter fw = new FileWriter("student.txt");//将新字符串写进文件 fw.write(str1); fw.close(); } return; default: System.out.println("请在 1--7 之间选择"); } } } } } if (flag) System.out.println("该学生不在系统中"); } void display() { System.out.println("共有" + n + "位学生信息；"); if (n != 0) { System.out.println("学生学号 学生姓名 年龄 性别 语文成绩 英语成绩 数学成绩 "); System.out.println("---------------------------------------------------------------------------------"); for (int i = 0; i < n; i++) { System.out.println(stu[i].code + " \t\t\t\t\t" + stu[i].name + " \t\t\t" + stu[i].age + " \t\t" + stu[i].sex + " \t\t" + stu[i].scoreChinese + " \t\t" + stu[i].scoreEnglish + " \t\t" + stu[i].scoreMath); } } } void del() throws IOException { System.out.println("请输入要删除学生的学号："); String code = sc.next(); boolean flag = false; for (int i = 0; i < n; i++) { if (stu[i].code.equals(code)) { flag = true; String dataStudent = (stu[i].code + " " + stu[i].name + " " + stu[i].age + " " + stu[i].sex + " " + stu[i].scoreChinese + " " + stu[i].scoreEnglish + " " + stu[i].scoreMath); if (i == n - 1) {//删除最后一个同学 stu[i] = null; n -= 1; } else {//删除的不是最后一个同学 for (int j = 1; i < n; j++) { stu[j] = stu[j + 1]; } stu[n - 1] = null; n -= 1; } File f = new File("student.txt"); long length = f.length(); FileReader fr = new FileReader("student.txt"); char[] ch = new char[(int) length]; fr.read(ch); fr.close(); String str = new String(ch); str = str.replace(dataStudent, " ");//删除操作 FileWriter fw = new FileWriter("student.txt");//写入新文件 fw.write(str); fw.close(); } } if (flag == false) System.out.println("该学号不存在！"); if (flag == true) System.out.println("删除成功"); } void seek() {//查找算法 int i; String item, code, name; boolean flag = false; System.out.println("---------------------------------------------"); System.out.println("1.按学号查询"); System.out.println("2.按姓名查询"); System.out.println("3.退出本菜单"); System.out.println("---------------------------------------------"); while (true) { System.out.println("请选择子菜单编号："); item = sc.next(); flag = false; switch (item) { case "1": System.out.println("请输入要查询的学生的学号："); code = sc.next(); for (i = 0; i < n; i++) if (stu[i].code.equals(code)) { flag = true; System.out.println("学生学号 学生姓名 年龄 性别 语文成绩 英语成绩 数学成绩 "); System.out.println("---------------------------------------------------------------------------------"); System.out.println(stu[i].code + " \t\t\t\t\t" + stu[i].name + " \t\t" + stu[i].age + " \t\t" + stu[i].sex + " \t\t" + stu[i].scoreChinese + " \t\t" + stu[i].scoreEnglish + " \t\t" + stu[i].scoreMath); } if (false == flag) System.out.println("该学号不存在！"); break; case "2": System.out.println("请输入要查询的学生的姓名："); name = sc.next(); for (i = 0; i < n; i++) if (stu[i].name.equals(name)) { flag = true; System.out.println("学生学号 学生姓名 年龄 性别 语文成绩 英语成绩 数学成绩 "); System.out.println("---------------------------------------------------------------------------------"); System.out.println(stu[i].code + " \t\t\t\t\t" + stu[i].name + " \t\t" + stu[i].age + " \t\t" + stu[i].sex + " \t\t" + stu[i].scoreChinese + " \t\t" + stu[i].scoreEnglish + " \t\t" + stu[i].scoreMath); } if (false == flag) System.out.println("该姓名不存在！"); break; case "3": return; default: System.out.println("请在 1--3 之间选择"); } } } static String getCode(int i) {//Judge类中使用 return stu[i].code; } void sort() throws IOException { int[] code = new int[n]; int temp; student stuTemp = new student(); for (int i = 0; i < n; i++) { code[i] = Integer.parseInt(stu[i].code); } for (int i = 0; i < n - 1; i++) {//使用选择排序法对学生对象进行排序 for (int j = i + 1; j < n; j++) { if (code[i] > code[j]) { temp = code[i]; code[i] = code[j]; code[j] = temp; stuTemp = stu[i]; stu[i] = stu[j]; stu[j] = stuTemp; } } } FileWriter fw = new FileWriter("student.txt");//按学号顺序将学生信息写入文件 for (int i = 0; i < n; i++) { String strTemp = (stu[i].code + " " + stu[i].name + " " + stu[i].age + " " + stu[i].sex + " " + stu[i].scoreChinese + " " + stu[i].scoreEnglish + " " + stu[i].scoreMath + " \r\n"); fw.write(strTemp); } fw.close(); } void readFile() throws IOException { File f = new File("student.txt"); try { if (!f.exists()) { f.createNewFile(); } FileWriter fileWriter = new FileWriter(f);//打开文件清空文件原有内容 fileWriter.write(""); fileWriter.flush(); fileWriter.close(); } catch (IOException e) { e.printStackTrace(); } int length = (int) f.length(); if (length == 0) return; FileReader fr = new FileReader("student.txt"); char[] ch = new char[length]; fr.read(ch); fr.close(); String str = new String(ch); //将字符串分割成数组并初始化 String regex1 = "\\s{2}"; String regex2 = "\\p{Blank}"; String[] strArray = str.split(regex1); n = strArray.length; for (int i = 0; i < n; i++) { stu[i] = new student(); } //初始化对象 for (int i = 0; i < strArray.length; i++) { String[] strArray2 = strArray[i].split(regex2); stu[i].code = strArray2[0]; stu[i].name = strArray2[1]; stu[i].age = strArray2[2]; stu[i].sex = strArray2[3]; stu[i].scoreChinese = strArray2[4]; stu[i].scoreEnglish = strArray2[5]; stu[i].scoreMath = strArray2[6]; } } }