Model类：
package com.ha.student;
import java.util.ArrayList;
import java.util.HashMap;
public class Model {
private HashMap<Integer,Student> mlist=new HashMap<Integer,Student>();
private ArrayList<Student>alist=new ArrayList<Student>();
public void addStudent(Student stu){
mlist.put(stu.getSid(), stu);
alist.add(stu);
}
public void deleteStudent(Student stu){
mlist.remove(stu.getSid());
alist.remove(stu);
}
public void xiugaiStudent(int sid,Student newstu){
alist.remove(bianliStudent(sid));
alist.add(newstu);
mlist.remove(sid);
mlist.put(sid,newstu);
}
public ArrayList<Student> returnStudent(){
return alist;
}
public Student bianliStudent(int sid){
return mlist.get(sid);
}
}
Student类：
package com.ha.student;
public class Student {
private int sid;
private String name;
private int age;
public Student(int sid,String name,int age){
this.sid=sid;
this.name=name;
this.age=age;
}
public String toString(){
return sid+"\t"+name+"\t"+age;
}
public int getSid() {
return sid;
}
public void setSid(int sid) {
this.sid = sid;
}
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;
}
}
view类：
package com.ha.student;
import java.util.List;
import java.util.Scanner;
public class View {
Scanner input=new Scanner(System.in);
public void welcome(){
System.out.println("欢迎进入学生管理系统！");
System.out.println("1:添加学生信息");
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:显示学生信息");
System.out.println("6:退出学生信息");
System.out.println("请您选择想要的操作！");
}
public Student vStudent(){
System.out.println("学生的学号：");
int sid=input.nextInt();
System.out.println("学生的姓名：");
String name=input.next();
System.out.println("学生的年龄：");
int age=input.nextInt();
Student stu=new Student(sid,name,age);
return stu;
}
public void display(List<Student> list){
for(Student stu:list){
System.out.println(stu);
}
}
}
Main类：
package com.ha.student;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
View v = new View();//新建View的对象v
Model m=new Model();
int choice;
while (true) {
v.welcome();//调用View类中的welcome方法
choice = input.nextInt();//进行选择操作
switch (choice) {
case 1://添加学生信息
if(v.vStudent()==null){
System.out.println("添加的学生为空,请重新添加");
}else{
m.addStudent(v.vStudent());
}
break;
case 2://删除学生信息
System.out.println("请输入要删除的学号：");
int deletesid=input.nextInt();
if(m.bianliStudent(deletesid)==null){
System.out.println("不存在该学生学号，请重新输入！");
}else{
m.deleteStudent(m.bianliStudent(deletesid));
}
break;
case 3://修改学生信息
System.out.println("请输入要修改的学号：");
int xiugaisid=input.nextInt();
if(m.bianliStudent(xiugaisid)==null){
System.out.println("不存在该学生学号，请重新输入！");
}else{
m.xiugaiStudent(xiugaisid,v.vStudent());
}
break;
case 4://查询学生信息
System.out.println("请输入要查询的学号：");
int chaxunsid=input.nextInt();
Student chaxunStudent=m.bianliStudent(chaxunsid);
if(chaxunStudent==null){
System.out.println("不存在该学生学号，请重新输入！");
}else{
System.out.println(chaxunStudent);
}
break;
case 5://显示学生信息
v.display(m.returnStudent());
break;
case 6://退出学生信息
return;
default://选择有误请重新选择！
System.out.println("选择有误请重新选择！");
break;
}//switch()
}//while()
}//main()
}//Main{}