java 商品 系统 代码

package entity;

public class Market {

private int id;//id

private int num;//数量

private String goods;//商品

private double price;//价格

public Market(int id, int num, String goods, double price) {
super();
this.id = id;
this.num = num;
this.goods = goods;
this.price = price;
}

public int getId() {
return id;
}

public void setId(int id) {
this.id = id;
}

public int getNum() {
return num;
}

public void setNum(int num) {
this.num = num;
}

public String getGoods() {
return goods;
}

public void setGoods(String goods) {
this.goods = goods;
}

public double getPrice() {
return price;
}

public void setPrice(double price) {
this.price = price;
}

public double calc( ){

double sum=price*num;

System.out.println("您消费共计："+sum+"￥");

return sum;

}

}
package test;

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

import entity.Market;

public class Test {

private static Map<Integer,Market> goods=new HashMap<Integer, Market>();

public static void main(String[] args) {

System.out.println("-------超市计价系统-------");

String goods1="可口可乐";
String goods2="爆米花";
String goods3="益达";

printTable("编号","商品","价格");
printTable("1",goods1,"3.0￥");
printTable("2",goods2,"5.0￥");
printTable("3",goods3,"10.0￥");

goods.put(1, new Market(1, 1, goods1, 3.0));

goods.put(2, new Market(2, 1, goods2, 5.0));

goods.put(3, new Market(3, 1, goods3, 10.0));

Scanner input = new Scanner(System.in);

System.out.println("请输入商品的编号:");

int num = input.nextInt();

System.out.println("请输入商品的数量");

int amount = input.nextInt();

Market market = goods.get(num);

market.setNum(amount);

market.calc();

}

private static void printTable(String row1,String row2,String row3 ) {

System.out.print(row1);

int times=12;

if (row2!="商品") {

times=5;

}

for (int i = 0; i < times; i++) {

System.out.print(" ");

}

System.out.print(row2);

for (int i = 0; i < 10; i++) {

System.out.print(" ");

}

System.out.print(row3);

System.out.println("\n");

}

}
//测试结果：
-------超市计价系统-------
编号 商品 价格

1 可口可乐 3.0￥

2 爆米花 5.0￥

3 益达 10.0￥

请输入商品的编号:
3
请输入商品的数量
5
您消费共计：50.0￥