package?com.imooc_collection;

import?java.util.HashMap;
import?java.util.Map;
import?java.util.Scanner;
import?java.util.Set;

public?class?MapTest?{
?/**
??*?用來承裝學(xué)生類型對(duì)象
??*?@param?args
??*/
?public?Map<String,Student>students;
?/**
??*?在構(gòu)造器中初始化student屬性
??*?@param?args
??*/
?public?MapTest(){
??this.students=new?HashMap<String,Student>();
?}
?/**
??*?測試添加：輸入學(xué)生ID，判斷是否被占用
??*?若違背占用，則輸入姓名，創(chuàng)建新學(xué)生對(duì)象，并且
??*?添加到student中
??*?@param?args
??*/
?public?void?testPut(){
??Scanner?console=new?Scanner(System.in);
??int?i=0;
??while(i<3){
???System.out.println("請(qǐng)輸入學(xué)生ID：");
???String?ID=console.next();
???//判斷該ID是否被占用
???Student?st=students.get(ID);
???if(st==null){
????System.out.println("請(qǐng)輸入學(xué)生姓名：");
????String?name=console.next();
????//創(chuàng)建一個(gè)新的學(xué)生對(duì)象
????Student?newStudent=new?Student(ID,name);
????//通過調(diào)用student的put方法，添加ID-學(xué)生映射
????students.put(ID,newStudent);
????System.out.println("成功添加學(xué)生："+students.get(ID).name);
????i++;
???}else{
????System.out.println("該學(xué)生ID已被占用！");
????continue;
???}
??}
?}
?
?/**
??*?測試Map的KepSet方法
??*?@param?args
??*/
?public?void?testKeySet(){
??//通過keySet方法，返回Map中的所有“鍵”的set集合
??Set<String>keySet=students.keySet();
??//取得students的容量
??System.out.println("總共有："+students.size()+"個(gè)學(xué)生！");
??//遍歷keySet，取得每一個(gè)鍵，再調(diào)用get方法取得每個(gè)鍵對(duì)應(yīng)的value
??for(String?stuId:keySet){
???Student?st=students.get(stuId);
???if(st!=null){
????System.out.println("學(xué)生："+st.name);
???}
??}
?}

?public?static?void?main(String[]?args)?{
??//?TODO?Auto-generated?method?stub
??MapTest?mt=new?MapTest();
??mt.testPut();
??mt.testKeySet();
?}

}