Hashset implements student management system

package com.zzu.test;

import java.util.HashSet;
import java.util.Scanner;

import com.zzu.vo.Student;

public class Main { private static HashSet<Student> set = new HashSet<Student>(); public static void main(String[] args) { System.out.println("************ *********************"); System.out.println("*Welcome to the student information management system"); System.out.println("** *******************************"); while (true) { menu(); } } static void menu() { System.out.println("1, add student information"); System.out.println("2, delete student information"); System.out.println("3, modify student information");//Address transfer System.out.println("4, query student information");//name System.out.println("input command:"); @SuppressWarnings("resource")




   Scanner scanner = new Scanner(System.in);
int order = scanner.nextInt();
switch (order) {
case 1:{
System.out.print("学号：");
String id=scanner.next();
System.out.print("姓名：");
String name=scanner.next();
System.out.print("手机号：");
String mobile=scanner.next();
System.out.print("家庭住址：");
String address=scanner.next();
Student student=new Student();
student.setId(id);
if(set.contains(student)) {
   System.out.println("已有学号，无法添加！");
   return;
}
student.setName(name);
student.setMobile(mobile);
student.setAddress(address);
set.add(student);
System.out.println("添加成功");
}
break;
case 2:{
   System.out.print("输入学号:");
   String id=scanner.next();
   Student student=new Student();
   student.setId(id);
   if(set.remove(student)) {
       System.out.println("删除成功");
       return;
   }
   break;
}
case 3:{
   System.out.println("输入学号：");
   String id=scanner.next();
   Student student=new Student();
   student.setId(id);
   if(!set.contains(student)) {
       System.out.println("无此学号！");
       return;
   }
   for(Student stu:set) {
   if(stu.getId().equals(id)) {
       System.out.print("新姓名：");
String name=scanner.next();
System.out.print("新手机号：");
String mobile=scanner.next();
System.out.print("新家庭住址：");
String address=scanner.next();
stu.setName(name);
stu.setMobile(mobile);
stu.setAddress(address);
System.out.println("修改成功");
       return;
   }
}
break;
}
case 4:{
System.out.println("输入学号：");
String id=scanner.next();
Student student =new Student();
student.setId(id);
if(!set.contains(student)) {
   System.out.println("无此学号！");
}
for(Student stu:set) {
   if(stu.getId().equals(id)) {
       System.out.println(stu);
       return;
   }
}
break;
}
default:
System.out.println("Instruction error!");
}
}

public static HashSet<Student> getSet() {
   return set;
}

   public static void setSet(HashSet<Student> set) {
       Main.set = set;
   }
}

package com.zzu.vo;

public class Student {
   private String id;
   private String name;
   private String mobile;
   private String address;
   public String getId() {
       return id;
   }
   public void setId(String id) {
       this.id = id;
   }
   public String getName() {
       return name;
   }
   public void setName(String name) {
       this.name = name;
   }
   public String getMobile() {
       return mobile;
   }
   public void setMobile(String mobile) {
       this.mobile = mobile;
   }
   public String getAdress() {
       return address;
   }
   public void setAddress(String ad) {
       this.address = ad;
   }
   @Override
   public String toString() {
       return "Student [id=" + id + ", name=" + name + ", mobile=" + mobile + ", ad=" + address + "]";
   }
   @Override
   public int hashCode() {
       return id.hashCode();
   }
   @Override
   public boolean equals(Object obj) {
       if(obj instanceof Student) {
           Student stu =(Student)obj;
           return stu.id.equals(this.id);
       }
       return false;
   }


}

Hashset implements student management system

Guess you like