Implement a simple student information management system using Java

Implement a simple student information management system with the Java
public class Student {
Private String NO; // Student ID (length 6)
Private String name; // name
private String idCard; // ID number (18)
Private int sex; // gender (male (1) / F (0))
Private int Age; // Age (1-100)

	public Student(){}
	public Student(String no, String name, String idCard, int sex, int age) {
		super();
		this.no = no;
		this.name = name;
		this.idCard = idCard;
		this.sex = sex;
		this.age = age;
	}
	
	public String getNo() {
		return no;
	}
	public void setNo(String no) {
		this.no = no;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getIdCard() {
		return idCard;
	}
	public void setIdCard(String idCard) {
		this.idCard = idCard;
	}
	public int getSex() {
		return sex;
	}
	public void setSex(int sex) {
		this.sex = sex;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	
	@Override
	public String toString() {
		return "Student [no=" + no + ", name=" + name + ", idCard=" + idCard + ", sex=" + sex + ", age=" + age
				+ "]";
	}
}

import java.util.Scanner;

StuMgr3_obj class {public
static int COUNT = 0; // current student
static int N = 1000; // Maximum number of students may be added to the
static Scanner input = new Scanner (System.in );

static Student[] stu = new Student[N];

public static void main(String[] args) {
	while(true) {
		StuMgr3_obj.showMenu();
		System.out.print("请输入<0-5>选择：");
		int sel = input.nextInt();
		if(sel < 0 || sel > 5) {
			System.out.println("没有此项菜单，请重新选择");
			continue;
		}
		
		switch (sel) {
		case 1:
			StuMgr3_obj.addStu();
			break;
		case 2:
			StuMgr3_obj.delStu();
			break;
		case 3:
			StuMgr3_obj.updateStu();
			break;
		case 4:
			StuMgr3_obj.selectStu();
			break;
		case 5:
			StuMgr3_obj.selectAllStu();
			break;
		case 0:
			StuMgr3_obj.exitSys();
			break;
		}
	}
}

/**
 * 菜单
 */
public static void showMenu() {
	System.out.println("---------学生信息管理系统----------");
	System.out.println("|		1. 增加学生信息			|");
	System.out.println("|		2. 删除学生信息			|");
	System.out.println("|		3. 修改学生信息			|");
	System.out.println("|		4. 查询学生信息			|");
	System.out.println("|		5. 查询所有学生信息		|");
	System.out.println("|		0. 退出学生系统			|");
	System.out.println("---------------------------------");
}

/**
 *1.增加学生信息
 */
public static void addStu() {
	System.out.print("请输入学号（一定是6位）:");
	String no;
	while(true) {	
		no = input.next();
		if(6 != no.length()) {
			System.out.println("请重新输入学号:");
			continue;
		}
		break;
	}
	
	System.out.println("请输入姓名");
	String name = input.next();
	String idCard;
	while (true) {
		System.out.println("请输入身份证号（一定是18位）:");
		idCard = input.next();
		if (18 != idCard.length()) {
			System.out.println("请重新输入身份证号");
		}else 
			break;
	} 
	System.out.println("请输入性别（男(1)/女(0)）");
	int sex = input.nextInt();
	System.out.println("请输入年龄（1-100）");
	int age = input.nextInt();
	
	stu[count] = new Student(no,name,idCard,sex,age);
	count++;
}

/**
 * 2.删除学生信息
 */
public static void delStu() {
	System.out.print("请输入要删除学生的学号：");
	String noString = input.next();	
	int index = getIndex(noString);
	if (index == -1) {
		System.out.println("系统中不存在该学生");			
	}else {
		stu[index] = stu[count-1];
		System.out.println("已删除成功");
		count--;
	}
	
}

/**
 * 3.修改学生信息
 */
public static void updateStu() {
	System.out.print("请输入要修改学生的学号：");
	String noString = input.next();	
	int index = getIndex(noString);
	if (index == -1) { 
		System.out.println("系统中不存在该学生");	
	}else {
		System.out.println("请输入学号:");
		stu[index].setNo(input.next());
		
		System.out.println("请重新输入姓名:");
		stu[index].setName(input.next());
		
		System.out.println("请重新输入身份证号:");
		stu[index].setIdCard(input.next());
		
		System.out.println("请重新输入性别:");
		stu[index].setSex(input.nextInt());
		
		System.out.println("请重新输入年龄（1-100）:");
		stu[index].setAge(input.nextInt()); 
	}	
}

/**
 *4.查询学生信息
 */
public static void selectStu() {
	System.out.print("请输入想查询学生的学号：");
	String noString = input.next();	
	int index = getIndex(noString);
	if (index == -1) { 
		System.out.println("系统中不存在该学生");	
	}else {
		System.out.println("学号:"+stu[index].getNo());
		System.out.println("姓名:"+stu[index].getName());
		System.out.println("身份证号:"+stu[index].getIdCard());
		System.out.println("性别（（男(1)/女(0)）："+stu[index].getSex());
		System.out.println("年龄:"+stu[index].getAge());
	}
}

/**
 * 5.查询所有学生信息
 */
public static void selectAllStu() {
	for (int i = 0; i < count; i++) {
		System.out.println("姓名为"+stu[i].getName()+"的学生信息为：");
		System.out.println("学号："+stu[i].getNo());
		System.out.println("身份证号："+stu[i].getIdCard());
		System.out.println("性别（男(1)/女(0)）："+stu[i].getSex());
		System.out.println("年龄："+stu[i].getAge());
		System.out.println();
	}
}

/**
 * 0.退出学生系统
 */
public static void exitSys() {
	System.out.println("已退出程序");
		System.exit(1);
	}

/**
 * @param noString 学号
 * @return 返回该学生在数组中的索引，不存在该学生则返回-1
 */
public static int getIndex(String noString) {
	for (int i = 0; i < count; i++) {
		if (stu[i].getNo().equals(noString)) {
			return i;
		}
	}
	return -1;
}

}

Results are as follows:



to achieve add, delete viewing student information.
Cabbage first to write blog, just take a look at it.