用Java写一个商城团购功能

```java public class GroupBuy { // 商品信息 private String name; // 商品名称 private int price; // 商品价格 private int number; // 团购人数 public GroupBuy(String name, int price, int number) { this.name = name; this.price = price; this.number = number; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getPrice() { return price;} public void setPrice(int price) { this.price = price;} public int getNumber() { return number;} public void setNumber(int number) {this.number = number;} // 计算团购价格的方法，满10人减5元，满20人减10元，依此类推。 public double groupBuyPrice(){ double groupbuyprice=0.0 ; if (number < 10 ){ groupbuyprice=price*number ; } else if (number >= 10 && number < 20){ groupbuyprice=(price-5)*number ; } else if (number >= 20 && number < 30){ groupbuyprice=(price-10)*number ; } else if (number >= 30 && number < 40){ groupbuyprice=(price-15)*number ; } else if (number >= 40 ){ groupbuyprice=(price-20)*number ; } return groupbuyprice ; }}