学生管理系统Demo

学生管理系统Demo

package Student;


import java.util.Scanner;


public class Student {
String[][] stu = { { "小名", "男", "1", "98" }, { "小的", "男", "2", "89" }, { "小个", "女", "3", "93" },
{ "小如", "女", "4", "94" }, { "小过", "男", "5", "97" } };


// 1查看 ok
void check() {
for (int i = 0; i < stu.length; i++) {
System.out.print("姓名：" + stu[i][0] + "            " + "姓别：" + stu[i][1] + "            " + "学号：" + stu[i][2]
+ "            " + "成绩：" + stu[i][3] + "            ");
System.out.println();
}
}


// 2根据学号查看 ok
void check1() {
System.out.println("请输入要查看的学生的学号");
Scanner scan = new Scanner(System.in);
String stunum = scan.nextLine();
int m = 0;
for (int i = 0; i < stu.length; i++) {
if (stu[i][2].compareTo(stunum) == 0) {
m = m + 1;
System.out.print("姓名：" + stu[i][0] + "            " + "姓别：" + stu[i][1] + "            " + "学号："
+ stu[i][2] + "            " + "成绩：" + stu[i][3] + "            ");
System.out.println();
}
}
if (m == 0) {
System.out.println("没有这个学生");
}
}


// 添加
void add() {
System.out.println("请输入添加学生的名字，性别，学号，成绩，以空格做分隔");
Scanner scan = new Scanner(System.in);
String[][] n = new String[stu.length + 1][4];
for (int i = 0; i < stu.length; i++) {
n[i] = stu[i];
}
for (int i = 0; i < 4; i++) {
n[stu.length][i] = scan.next();
}
stu = null;
stu = new String[n.length][4];
for (int i = 0; i < stu.length; i++) {
stu[i] = n[i];
}
this.check();


}


// 3删除 //出现重复
void delete() {
this.check();
System.out.println("请输入要删除的学生的学号");
Scanner scan = new Scanner(System.in);
String stunum = scan.nextLine();
int m = 0;
for (int i = 0; i < stu.length - 1; i++) {
if (stu[i][2].compareTo(stunum) == 0) {
m = m + 1;
for (int g = i; g < stu.length - 1; g++) {
stu[g] = null;
stu[g] = stu[g + 1];
}


}
}


if (m == 0) {
System.out.println("没有这个学生");
}
String[][] nng = new String[stu.length - 1][4];
for (int i = 0; i < nng.length; i++) {
nng[i] = stu[i];
}
stu = null;
stu = new String[nng.length][4];
for (int i = 0; i < stu.length; i++) {
stu[i] = nng[i];
}
this.check();


}


// 4修改 ok
void gai() {
this.check();
System.out.println("请输入要修改的学生的学号");
Scanner scan = new Scanner(System.in);
String stunum = scan.nextLine();
int m = 0;
for (int i = 0; i < stu.length; i++) {
if (stu[i][2].compareTo(stunum) == 0) {
m = m + 1;
System.out.print("请输入要修改的学生数据序号");
System.out.println("1.姓名                " + "2.姓别                  " + "3.学号                 "
+ "4.成绩             ");
String num = scan.nextLine();


if (num.compareTo("1") == 0) {
System.out.println("您要修改的是姓名");
System.out.println("请输入新数据");
Scanner nnu1 = new Scanner(System.in);
stu[Integer.parseInt(stunum) - 1][0] = nnu1.nextLine();
}
if (num.compareTo("2") == 0) {
System.out.println("您要修改的是姓别");
System.out.println("请输入新数据");
Scanner nnu2 = new Scanner(System.in);
stu[Integer.parseInt(stunum) - 1][1] = nnu2.nextLine();
}
if (num.compareTo("3") == 0) {
System.out.println("您要修改的是学号");
System.out.println("请输入新数据");
Scanner nnu3 = new Scanner(System.in);
stu[Integer.parseInt(stunum) - 1][2] = nnu3.nextLine();
}
if (num.compareTo("4") == 0) {
System.out.println("您要修改的是成绩");
System.out.println("请输入新数据");
Scanner nnu4 = new Scanner(System.in);
stu[Integer.parseInt(stunum) - 1][3] = nnu4.nextLine();
}
}


}
if (m == 0) {
System.out.println("没有这个学生");
}
this.check();
}


// 5退出
void exit() {
System.out.println("退出成功");
System.exit(0);
}


void login() {
A: for (int c = 0;; c++) {
String[][] am = { { "123", "123" }, { "luqin", "5789" } };
System.out.println("请输入账号和密码,以空格做分隔，只有三次机会");
Scanner nno = new Scanner(System.in);
String acc = nno.next();
String mi = nno.next();


for (int m = 0; m < am.length; m++) {
if ((am[m][0].compareTo(acc) == 0) & (am[m][1].compareTo(mi) == 0)) {
System.out.println("登陆成功");
System.out.println("请输入接下来的操作");
System.out
.println("1.查看所有           2.学号查看           3.添加           4.修改        5删除           6退出");
Student bba = new Student();
Scanner eb = new Scanner(System.in);


for (;;) {
switch (eb.next()) {
case "1":
bba.check();
System.out.println(
"1.查看所有           2.学号查看           3.添加           4.修改        5删除           6退出");
break;
case "2":
bba.check1();
System.out.println(
"1.查看所有           2.学号查看           3.添加           4.修改        5删除           6退出");
break;
case "3":
bba.add();
System.out.println(
"1.查看所有           2.学号查看           3.添加           4.修改        5删除           6退出");
break;
case "4":
bba.gai();
System.out.println(
"1.查看所有           2.学号查看           3.添加           4.修改        5删除           6退出");
break;
case "5":
bba.delete();
System.out.println(
"1.查看所有           2.学号查看           3.添加           4.修改        5删除           6退出");
break;
case "6":
bba.exit();
System.out.println("退出成功");
break;


}
}
/*
* for(;;) {
* 
* System.out.
* println("1.查看所有           2.学号查看           3.添加           4.修改        5删除           6退出"
* ); if(eb.next().compareTo("1")==0) { bba.check();
* System.out.println("请输入接下来的操作"); System.out.
* println("1.查看所有           2.学号查看           3.添加           4.修改        5删除           6退出"
* );
* 
* } else if(eb.next().compareTo("2")==0) { bba.check1();
* System.out.println("请输入接下来的操作"); System.out.
* println("1.查看所有           2.学号查看           3.添加           4.修改        5删除           6退出"
* );
* 
* } else if(eb.next().compareTo("3")==0) { bba.add();
* System.out.println("请输入接下来的操作"); System.out.
* println("1.查看所有           2.学号查看           3.添加           4.修改        5删除           6退出"
* );
* 
* } else if(eb.next().compareTo("4")==0) { bba.gai();
* System.out.println("请输入接下来的操作"); System.out.
* println("1.查看所有           2.学号查看           3.添加           4.修改        5删除           6退出"
* );
* 
* } else if(eb.next().compareTo("5")==0) { bba.delete();
* System.out.println("请输入接下来的操作"); System.out.
* println("1.查看所有           2.学号查看           3.添加           4.修改        5删除           6退出"
* );
* 
* 
* } else if(eb.next().compareTo("6")==0) { bba.exit();
* System.out.println("退出成功"); } }
*/
} else {
if (c >= 3) {
System.out.println("对不起，已失效");
break A;
}
c = c + 1;
int s = 2;
s--;
System.out.println("你还有" + (3 - c) + "次机会");
break;
}
}
}
}


public static void main(String[] args) {
Student mma = new Student();


mma.login();


}


}