java基础阶段学生信息管理系统集合版

基于集合的小案例，没有涉及到IO流，没有异常处理，只是简单的用集合存储数据元素，实现CRUD。

package
/*
 * 学号默认生成，在学生类中创建一个静态常量，用来给每个学生的学号赋值，每次赋值后，执行++一次
 */
import java.util.ArrayList;

import java.util.ListIterator;
import java.util.Scanner;

public class Crm {

	public static void main(String[] args) {
		ArrayList<Student3> list = new ArrayList<Student3>();
		Student3 student3 = new Student3();
		Scanner sc = new Scanner(System.in);
		System.out.println("欢迎登陆学生信息后台管理系统");
		while (true) {
			System.out.println("-----------学生信息管理系统----------");
			System.out.println();
			System.out.println("1、添加  2、查询  3、修改  4、删除  5、退出系统");
			System.out.println();
			System.out.println("---------------------------------");
		String choose = sc.next();
		switch (choose) {
		case "1":
			student3.add(list);
			break;
		case "2":
			student3.query(list);
			break;
		case "3":
			student3.update(list);
			break;
		case "4":
			student3.delete(list);
			break;
		case "5":
			student3.exit();
			break;
			}
		}

	}

}
class Student3{
	private String name;
	private int age;
	private Integer stuNo;
	static int id=0001;
	public Student3() {
		super();
	}
	public Student3(String name, int age, int stuNo) {
		super();
		this.name = name;
		this.age = age;
		this.stuNo = stuNo;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	
	public Integer getStuNo() {
		return stuNo;
	}
	public void setStuNo(Integer stuNo) {
		this.stuNo = stuNo;
	}
	@Override
	public String toString() {
		return "Stu [name=" + name + ", age=" + age + ", stuNo=" + stuNo + "]";
	}
	
	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + age;
		result = prime * result + ((name == null) ? 0 : name.hashCode());
		result = prime * result + ((sc == null) ? 0 : sc.hashCode());
		result = prime * result + stuNo;
		return result;
	}
	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		Student3 other = (Student3) obj;
		if (age != other.age)
			return false;
		if (name == null) {
			if (other.name != null)
				return false;
		} else if (!name.equals(other.name))
			return false;
		if (sc == null) {
			if (other.sc != null)
				return false;
		} else if (!sc.equals(other.sc))
			return false;
		if (stuNo != other.stuNo)
			return false;
		return true;
	}

	Scanner sc = new Scanner(System.in);
	public void add(ArrayList<Student3> list) {
		System.out.println("请输入姓名：");
		String name = sc.next();
		System.out.println("请输入年龄：");
		int age = sc.nextInt();
		list.add(new Student3(name,age,id));
		id++;
		new Student3().query(list);
		System.out.println("是否继续添加学生信息y or n:");
		String pd = sc.next();
		if((pd.equals("y"))||pd.equals("Y")) {
			new Student3().add(list);
		}
	}
	public void update(ArrayList<Student3> list) {
		new Student3().query(list);
		System.out.println("请输入要修改学生的学号：");
		Integer id = sc.nextInt();
		System.out.println("请输入修改后的姓名");
		String name = sc.next();
		System.out.println("请输入修改后的年龄：");
		int age = sc.nextInt();
		ListIterator<Student3> listIterator = list.listIterator();
		while(listIterator.hasNext()) {
			Student3 s = listIterator.next();
			if(s.getStuNo().equals(id)) {
				s.setName(name);
				s.setAge(age);
			}
		}
		new Student3().query(list);
	}
	public void query(ArrayList<Student3> list) {
		ListIterator<Student3> listIterator = list.listIterator();
		if(list.size()!=0&&list!=null) {
			System.out.println("学号\t姓名\t年龄\t");
			while(listIterator.hasNext()) {
				Student3 s = listIterator.next();
				System.out.println(s.getStuNo()+"\t"+s.getName()+"\t"+s.getAge());
			}
		}else {
			System.out.println("没有学生信息，请添加后在进行查询");
		}
	}
	public void delete(ArrayList<Student3> list) {
		new Student3().query(list);
		System.out.println("请输入要删除学生信息的学号：");
		int id = sc.nextInt();
		ListIterator<Student3> listIterator = list.listIterator();
		while(listIterator.hasNext()) {
			Student3 s = listIterator.next();
			if(s.getStuNo().equals(id)) {
				listIterator.remove();
			}
		}
		new Student3().query(list);
	}
	public void exit() {
		System.exit(0);
	}
}