小静的心路历程--javase基础语法第一章--基本语法之引用数据类型

我们知道引用数据类型有三种:数组,jdk类,接口
首先我们看看引用数据类型
public class Goods{
public String brand;//品牌
public double cpu;//cpu
public double screen;//屏幕尺寸
public double money;//价格
public int store;//库存
public int code;//编码

}

public class Checkgoods{
public static void main(String[] args){
ArrayList<Goods> goods=new ArrayList<Goods>();
addGoods(goods); //存储商品信息
System.out.println("********欢迎使用仓库管理系统********");
while(true){
System.out.println("请输入您对系统的操作");
System.out.println("1.查看");
System.out.println("2.修改库存");
System.out.println("3.退出");
Scanner inputNumber=new Scanner(System.in); 
int operationNumber=inputNumber.nextInt();  //获取系统输入的Int值
if(operationNumber==1){
lookThrough(goods);//总览
continue;
}
else if(operationNumber==2){
editInfo(goods);//修改库存
continue;
}

else if(operationNumber==3){
System.out.println("********感谢使用仓库管理系统********");
break;
}

}
}

public static void editInfo(ArrayList<Goods> goods){  //修改库存 获取值 修改
System.out.println("请输入您要修改的品牌的代号");
Scanner nameInput=new Scanner(System.in);
int nameValue=nameInput.nextInt();
int judge=1;
for(int i=0;i<goods.size();i++){
if(nameValue==goods.get(i).code){
System.out.println("您即将修改的商品:"+goods.get(i).brand);
System.out.println("是否确定修改该商品属性？1/是,2/否");
int confirmInput=nameInput.nextInt();
if(confirmInput==1){
System.out.println("请输入您将修改的库存大小为多少？");
int storeInput=nameInput.nextInt(); //库存大小
goods.get(i).store=storeInput;
System.out.println("修改完成!");
break;
}else{
System.out.println("已经退出修改系统");
break;
}
}else{
judge=0;
//System.out.println("未找到该品牌"+nameValue);
continue;
}
}
if(judge==0){
System.out.println("未找到该品牌");
}
}

public static void lookThrough(ArrayList<Goods> goods){  //总览
System.out.println("********以下为仓库的货品信息********");
System.out.println("品牌"+"   "+"尺寸"+"   "+"cpu"+"   "+"单价"+"   "+"库存"+"  "+"商品编码");
int totalCount=0;//总库存
double moneyCount=0;//总金额
for(int i=0;i<goods.size();i++){
totalCount+=goods.get(i).store; //总库存
moneyCount+=(goods.get(i).money*goods.get(i).store); //总金额
System.out.println(goods.get(i).brand+"   "+goods.get(i).screen+"   "+goods.get(i).cpu+"   "+goods.get(i).money+"   "+goods.get(i).store+"  "+goods.get(i).code);
}
System.out.println("总金额:"+moneyCount);
System.out.println("总库存:"+totalCount);
}

public static void addGoods(ArrayList<Goods> goods){ //存储商品信息

Goods s1=new Goods();   //数据类型为Goods 
Goods s2=new Goods();
Goods s3=new Goods();
Goods s4=new Goods();
Goods s5=new Goods();

s1.brand="1.华为";
s1.money=2700.0;
s1.screen=3.5;
s1.cpu=3.0;
s1.store=20;
s1.code=1;

s2.brand="2.小米";
s2.money=2600.0;
s2.screen=3.0;
s2.cpu=2.5;
s2.store=50;
s2.code=2;

s3.brand="3.魅族";
s3.money=2500.0;
s3.screen=2.5;
s3.cpu=2.0;
s3.store=60;
s3.code=3;

s4.brand="4.oppo";
s4.money=2400.0;
s4.screen=2.0;
s4.cpu=1.5;
s4.store=70;
s4.code=4;

s5.brand="5.vivo";
s5.money=2300.0;
s5.screen=1.5;
s5.cpu=1.0;
s5.store=80;
s5.code=5;

goods.add(s1);
goods.add(s2);
goods.add(s3);
goods.add(s4);
goods.add(s5);
}

}
当然这是一种比较笨的方法否，你也可以自定义构造方法 集合.add(new 类名(成员参数值))
接下来我们看看接口
public class Test {
public static void main(String[] args) {
Computer c=new Computer();
c.useUsB(new Mouse());
}

}
public class Computer {
public static void open() {
System.out.println("电脑开机");
}
public static void close() {
System.out.println("电脑关机");
}
public static void useUsB(Usb usb) {
usb.close();
usb.open();
}

}
public interface Usb {

public abstract void open();
public abstract void close();

}
public class Mouse implements Usb{

@Override
public void open() {
// TODO Auto-generated method stub
System.out.println("鼠标通过接口开机");
}

@Override
public void close() {
// TODO Auto-generated method stub
System.out.println("鼠标通过接口关机");
}

}
电脑通过接口类一定要经过外设设备才能连接使用,