P168 实战练习（权限修饰符）

创建Game类，运行代码如下：

 package org.hanqi.pn0120;

 public class Game {

     private String name;
     private String category;
     private int totalcost = 10000;

     public String getName() {
         return name;
     }
     public void setName(String name) {
         this.name = name;
     }
     public String getCategory() {
         return category;
     }
     public void setCategory(String category) {
         this.category = category;
     }
     public int getTotalcost() {
         return totalcost;
     }
     public void setTotalcost(int totalcost) {
         this.totalcost = totalcost;
     }

     public Game(String name, String category) {
         super();
         this.name = name;
         this.category = category;
     }    

     public void cost1(int cost)
     {
         if(cost <= 0)
         {
             System.out.println("做游戏的钱呢？！");
         }
         else if(cost>this.totalcost)
         {
             int excess=cost-this.totalcost;
             System.out.println("超出预算了，超了"+excess+"金额的预算");
         }
         else
         {
             this.totalcost=cost;
             System.out.println("这次预算是"+this.totalcost);
         }
     }    

     private int sales;
     public int getSales()
     {
         return this.sales;
     }
     public void money(int number,int price)
     {
         if(number<=0)
         {
             System.out.println("一份都没卖出去，赔钱了，公司要倒闭");
         }
         else if(price<=0)
         {
             System.out.println("为什么定价是0？");
         }
         else if(price>50)
         {
             System.out.println("定价太高了");
         }
         else
         {
             this.sales=number*price;
             System.out.println("销售额是"+sales);

         if(this.sales<this.totalcost)
         {
             int debt = this.totalcost-this.sales;
             System.out.println("入不敷出，公司倒闭，欠了 "+debt+" 金额的债务");
         }
         else
         {
             int profit = this.sales-this.totalcost;
             System.out.println("挣钱了，利润是"+profit);
         }
         }
     }

     public static void main(String[]args)
     {
         Game myGame = new Game("你与我的星空","Galgame");
              System.out.println("游戏名称是："+myGame.getName());
              System.out.println("游戏类型为："+myGame.getCategory());
              myGame.cost1(-10000);
              myGame.cost1(20000);
              myGame.cost1(2000);
              myGame.money(0, 25);
              myGame.money(14, 0);
              myGame.money(200, 88);
              myGame.money(200, 25);
     }
 }

则运行代码为：