1 //自定义类
2 public class FruitItem {
3     int     ID;            //商品编号
4     String     name;        //名称
5     double     price;        //单价
6 }

  1 import java.util.ArrayList;
  2 import java.util.Scanner;
  3 
  4 /*
  5  * 超市管理系统
  6  * 实现 : 
  7  *         1.商品数据初始化
  8  *         2.菜单
  9  *         3.选择功能
 10  *         4.增删改查
 11  */
 12 public class FruitStore {
 13     public static void main(String[] args) {
 14         
 15         //集合
 16         ArrayList<FruitItem> array = new ArrayList<FruitItem>();
 17         
 18         //商品数据初始化
 19         init(array);
 20         
 21         while (true) {
 22             //菜单选择
 23             mainMenu();
 24             
 25             //选择功能
 26             int choose = chooseFunction();
 27             
 28             switch (choose) {
 29             case 1:
 30                 //查
 31                 showFruitList(array);
 32                 break;
 33             case 2:
 34                 //增
 35                 addFruitItem(array);
 36                 break;
 37             case 3:
 38                 delFruitItem(array);
 39                 break;
 40             case 4:
 41                 updateFruitItem(array);
 42                 break;
 43             case 5:
 44                 System.out.println("退出系统");
 45                 return;
 46             default:
 47                 System.out.println("没有选择的功能");
 48                 break;
 49             }
 50         }
 51         
 52     }
 53     
 54     //初始化
 55     public static void init(ArrayList<FruitItem> array) {
 56         FruitItem item1 = new FruitItem();
 57         item1.ID = 101;
 58         item1.name = "苹果";
 59         item1.price = 5.5;
 60         
 61         FruitItem item2 = new FruitItem();
 62         item2.ID = 102;
 63         item2.name = "菠萝";
 64         item2.price = 3.5;
 65         
 66         FruitItem item3 = new FruitItem();
 67         item3.ID = 103;
 68         item3.name = "甘蔗";
 69         item3.price = 1.5;
 70         
 71         array.add(item1);
 72         array.add(item2);
 73         array.add(item3);
 74         
 75     }
 76     
 77     public static void mainMenu() {
 78         System.out.println("=========================欢迎光临水果超市=========================");
 79         System.out.println("1:查询货物 2:添加新货物 3:删除货物 4:修改货物 5:退出系统");
 80         System.out.println("请您输入要操作的功能序号:");
 81     }
 82     
 83     //菜单
 84     public static int chooseFunction() {
 85         Scanner sc = new Scanner(System.in);
 86         return sc.nextInt();
 87     }
 88     
 89     //查询
 90     public static void showFruitList(ArrayList<FruitItem> array) {
 91         System.out.println("=======================商品库存清单=======================");
 92         System.out.println("商品编号\t商品名称\t商品单价");
 93         for (int i = 0; i < array.size(); i++) {
 94             FruitItem item = array.get(i);
 95             System.out.println(item.ID+"\t"+item.name+"\t"+item.price);
 96         }
 97     }
 98     
 99     //添加
100     public static void addFruitItem(ArrayList<FruitItem> array) {
101         FruitItem newItem = new FruitItem();
102         Scanner sc = new Scanner(System.in);
103         
104         System.out.println("请输入ID");
105         newItem.ID = sc.nextInt();
106         System.out.println("请输入名称");
107         newItem.name = sc.next();
108         System.out.println("输入商品的单价");
109         newItem.price = sc.nextDouble();
110         
111         array.add(newItem);
112         System.out.println("添加成功");
113     }
114     
115     //删除
116     public static void delFruitItem(ArrayList<FruitItem> array) {
117         System.out.println("输入删除ID");
118         Scanner sc = new Scanner(System.in);
119         int ID = sc.nextInt();
120         
121         for (int i = 0; i < array.size(); i++) {
122             if (array.get(i).ID == ID) {
123                 array.remove(array.get(i));
124                 System.out.println("删除成功");
125                 return;
126             }
127         }
128         
129         System.out.println("ID 不存在");
130     }
131     
132     //修改
133     public static void updateFruitItem(ArrayList<FruitItem> array) {
134         System.out.println("输入ID");
135         Scanner sc = new Scanner(System.in);
136         int ID = sc.nextInt();
137         
138         for (int i = 0; i < array.size(); i++) {
139             FruitItem item = array.get(i);
140             if (item.ID == ID) {
141                 System.out.println("请输入ID");
142                 item.ID = sc.nextInt();
143                 System.out.println("请输入名称");
144                 item.name = sc.next();
145                 System.out.println("输入商品的单价");
146                 item.price = sc.nextDouble();
147                 System.out.println("修改成功");
148                 return;
149             }
150         }
151     }
152 
153 }