{"id":1099,"date":"2020-02-07T10:07:22","date_gmt":"2020-02-07T02:07:22","guid":{"rendered":"http:\/\/www.rain1024.com\/?p=1099"},"modified":"2023-08-07T20:57:24","modified_gmt":"2023-08-07T12:57:24","slug":"%e3%80%8aheadfirst%e8%ae%be%e8%ae%a1%e6%a8%a1%e5%bc%8f%e3%80%8b%e7%ac%ac%e4%b9%9d%e7%ab%a0%e8%bf%ad%e4%bb%a3%e5%99%a8%e4%b8%8e%e7%bb%84%e5%90%88%e6%a8%a1%e5%bc%8f-%e8%af%bb%e4%b9%a6%e7%ac%94%e8%ae%b0","status":"publish","type":"post","link":"http:\/\/rain1024.com\/index.php\/2020\/02\/07\/%e3%80%8aheadfirst%e8%ae%be%e8%ae%a1%e6%a8%a1%e5%bc%8f%e3%80%8b%e7%ac%ac%e4%b9%9d%e7%ab%a0%e8%bf%ad%e4%bb%a3%e5%99%a8%e4%b8%8e%e7%bb%84%e5%90%88%e6%a8%a1%e5%bc%8f-%e8%af%bb%e4%b9%a6%e7%ac%94%e8%ae%b0\/","title":{"rendered":"\u300aHeadFirst\u8bbe\u8ba1\u6a21\u5f0f\u300b\u7b2c\u4e5d\u7ae0\u8fed\u4ee3\u5668\u4e0e\u7ec4\u5408\u6a21\u5f0f-\u8bfb\u4e66\u7b14\u8bb0"},"content":{"rendered":"

\u300aHeadFirst\u8bbe\u8ba1\u6a21\u5f0f\u300b\u7b2c\u4e5d\u7ae0\u8fed\u4ee3\u5668\u4e0e\u7ec4\u5408\u6a21\u5f0f-\u8bfb\u4e66\u7b14\u8bb0<\/h1>\n

\u6848\u4f8b\u4ee3\u7801\u94fe\u63a5\uff1ahttps:\/\/github.com\/rainweb521\/My-tutorial\/tree\/master\/Design_patterns<\/h3>\n

1. \u83dc\u5355\u7684\u8fed\u4ee3<\/h2>\n

\u672c\u4f8b\u4e2d\u9910\u5385\u548c\u714e\u997c\u5c4b\u5408\u5e76\u4e86\uff0c\u4ed6\u4eec\u9700\u8981\u5728\u5ba2\u4eba\u70b9\u9910\u7684\u65f6\u5019\uff0c\u80fd\u591f\u628a\u4e8c\u8005\u7684\u83dc\u5355\u5185\u5bb9\u90fd\u6253\u5370\u51fa\u6765\uff0c\u4f46\u662f\u4ed6\u4eec\u4e4b\u524d\u5206\u522b\u4f7f\u7528ArrayList\u548c\u6570\u7ec4\u6765\u5b58\u50a8\u83dc\u5355\u5185\u5bb9\uff0c\u8fd9\u6837\u6253\u5370\u7684\u65f6\u5019\u5c31\u4f1a\u6709\u91cd\u590d\uff0c\u591a\u6b21\u8c03\u7528\u7684\u95ee\u9898\u3002<\/h4>\n

\u8fd9\u662f\u57fa\u7840\u83dc\u5355<\/p>\n

public class MenuItem {\n    String name;\n    String description;\n    boolean vegetarian;\n    double price;\n    public MenuItem(String name, String description, boolean vegetarian, double price) {\n        this.name = name;\n        this.description = description;\n        this.vegetarian = vegetarian;\n        this.price = price;\n    }\n\n    public String getName() {\n        return name;\n    }\n\n    public void setName(String name) {\n        this.name = name;\n    }\n\n    public String getDescription() {\n        return description;\n    }\n\n    public void setDescription(String description) {\n        this.description = description;\n    }\n\n    public boolean getVegetarian() {\n        return vegetarian;\n    }\n\n    public void setVegetarian(boolean vegetarian) {\n        this.vegetarian = vegetarian;\n    }\n\n    public double getPrice() {\n        return price;\n    }\n\n    public void setPrice(double price) {\n        this.price = price;\n    }\n}\n<\/code><\/pre>\n
\u8fd9\u662f\u714e\u997c\u5c4b\u7684\u83dc\u5355<\/h4>\n
public class PancakeHouseMenu {\n    ArrayList menuItems;\n    public PancakeHouseMenu() {\n        menuItems = new ArrayList();\n        addItem(\"K&B Pancake Breakfast\",\"Pancakes with scrambled eggs , and toast\",\n                true,2.99);\n    }\n    public void addItem(String name, String description, boolean vegetarian, double price){\n        MenuItem menuItem = new MenuItem(name,description,vegetarian,price);\n        menuItems.add(menuItem);\n    }\n    public ArrayList getMenuItems(){\n        return menuItems;\n    }\n}\n<\/code><\/pre>\n
\u8fd9\u662f\u9910\u5385\u7684\u83dc\u5355<\/h4>\n
public class DinerMenu {\n    static final int MAX_ITEMS = 6;\n    int numberOfItems = 0 ;\n    MenuItem[] menuItems;\n\n    public DinerMenu() {\n        menuItems = new MenuItem[MAX_ITEMS];\n        addItem(\"Vegetarian BLT\",\n                \"(Fakin') BAcon with lettuce & tomato on whole wheat\",true,2.99);\n    }\n\n    private void addItem(String name, String description, boolean vegetarian, double price) {\n        MenuItem menuItem = new MenuItem(name,description,vegetarian,price);\n        if (numberOfItems >= MAX_ITEMS){\n            System.out.println(\"Sorry,meny is full\");\n        }else {\n            menuItems[numberOfItems]  = menuItem;\n            numberOfItems += 1;\n        }\n    }\n\n    public MenuItem[] getMenuItems() {\n        return menuItems;\n    }\n}\n<\/code><\/pre>\n
\n  \u5982\u679c\u60f3\u8981\u6253\u5370\u4e24\u4efd\u83dc\u5355\uff0c\u5c31\u9700\u8981\u5b9e\u4f8b\u5316\u8fd9\u4e24\u4e2a\u7c7b\uff0c\u7136\u540e\u901a\u8fc7getMenuItems\u65b9\u6cd5\u83b7\u53d6\u83dc\u5355\u7ec4\uff0c\u518d\u5206\u522b\u5faa\u73af\u6253\u5370\u51fa\u6765\u3002<\/p>\n
  \u82e5\u4ee5\u540e\u518d\u589e\u52a0\u83dc\u5355\uff0c\u5c31\u9700\u8981\u7ee7\u7eed\u8fd9\u6837\u66f4\u6539\u4ee3\u7801\uff0c\u5b9e\u73b0\u65b0\u7684\u5faa\u73af\u3002\n<\/p><\/blockquote>\n
2.\u5c01\u88c5\u904d\u5386<\/h2>\n
\u6211\u4eec\u65b0\u5efa\u4e00\u4e2a\u5bf9\u8c61\uff0c\u5c06\u5b83\u79f0\u4e3a\u8fed\u4ee3\u5668\uff0c\u5229\u7528\u5b83\u6765\u5c01\u88c5\u201c\u904d\u5386\u96c6\u5408\u5185\u7684\u6bcf\u4e2a\u5bf9\u8c61\u7684\u8fc7\u7a0b\u201d\u3002<\/p>\n
\u521b\u5efa\u7edf\u4e00\u7684\u8fed\u4ee3\u5668\u63a5\u53e3<\/p>\n
public interface Iterator {\n    boolean hasNext();\n    Object next();\n}\n<\/code><\/pre>\n
\u63a5\u4e0b\u6765\u5b9e\u73b0\u5177\u4f53\u7684\u8fed\u4ee3\u5668\uff0c\u9996\u5148\u662f\u9910\u5385\u7684<\/p>\n
public class DinnerMenuIterator implements Iterator {\n    MenuItem[] menuItems;\n    int position = 0;\n\n    public DinnerMenuIterator(MenuItem[] menuItems) {\n        this.menuItems = menuItems;\n    }\n    public boolean hasNext() {\n        if (position>=menuItems.length || menuItems[position]==null){\n            return false;\n        }else{\n            return true;\n        }\n    }\n    public Object next() {\n        MenuItem menuItem = menuItems[position];\n        position+=1;\n        return menuItem;\n    }\n}\n<\/code><\/pre>\n
\u5728DinerMenu\u4e2d\u52a0\u5165\u8fed\u4ee3\u5668\u65b9\u6cd5<\/p>\n
 public Iterator createIterator(){\n        return new DinnerMenuIterator(menuItems);\n    }\n<\/code><\/pre>\n
\u5b9e\u73b0\u714e\u997c\u5c4b\u7684\u8fed\u4ee3\u5668\u5bf9\u8c61<\/p>\n
public class PancakeHouseIterator implements Iterator{\n    ArrayList<MenuItem> menuItems;\n    int position = 0;\n\n    public PancakeHouseIterator(ArrayList<MenuItem> menuItems) {\n        this.menuItems = menuItems;\n    }\n    public boolean hasNext() {\n        if (position>=menuItems.size() || menuItems.get(position)==null){\n            return false;\n        }else{\n            return true;\n        }\n    }\n    public MenuItem next() {\n        MenuItem menuItem = menuItems.get(position);\n        position+=1;\n        return menuItem;\n    }\n}\n<\/code><\/pre>\n
\u5728PancakeHouseMenu\u4e2d\u52a0\u5165\u8fed\u4ee3\u5668\u65b9\u6cd5<\/p>\n
public Iterator createIterator(){\n        return new PancakeHouseIterator(menuItems);\n    }\n<\/code><\/pre>\n
\u4fee\u6b63\u5973\u62db\u5f85\u7684\u4ee3\u7801<\/p>\n
\u6211\u4eec\u9700\u8981\u5c06\u8fed\u4ee3\u5668\u4ee3\u7801\u6574\u5408\u8fdb\u5973\u62db\u5f85\u4e2d\u3002\u6211\u4eec\u5e94\u8be5\u6446\u8131\u539f\u672c\u5197\u4f59\u7684\u90e8\u5206\u3002\u6574\u5408\u7684\u505a\u6cd5\u76f8\u5f53\u76f4\u63a5:\u9996\u5148\u521b\u5efa\u4e00\u4e2a printmenuo\u65b9\u6cd5,\u4f20\u5165\u4e00\u4e2a\u8fed\u4ee3\u5668\u5f53\u505a\u6b64\u65b9\u6cd5\u7684\u53c2\u6570,\u7136\u540e\u5bf9\u6bcf\u4e00\u4e2a\u83dc\u5355\u90fd\u4f7f\u7528 createlterator()\u65b9\u6cd5\u6765\u68c0\u7d22\u8fed\u4ee3\u5668,\u5e76\u5c06\u8fed\u4ee3\u5668\u4f20\u5165\u65b0\u65b9\u6cd5<\/p>\n
public class Waitress {\n    PancakeHouseMenu pancakeHouseMenu;\n    DinerMenu dinerMenu;\n    public Waitress(PancakeHouseMenu pancakeHouseMenu, DinerMenu dinerMenu) {\n        this.pancakeHouseMenu = pancakeHouseMenu;\n        this.dinerMenu = dinerMenu;\n    }\n    public void printMenu(){\n        Iterator pancakeHouseMenuIterator = pancakeHouseMenu.createIterator();\n        Iterator dinerMenuIterator = dinerMenu.createIterator();\n        printMenu(pancakeHouseMenuIterator);\n        printMenu(dinerMenuIterator);\n    }\n    private void printMenu(Iterator iterator) {\n        while (iterator.hasNext()){\n            MenuItem menuItem = (MenuItem) iterator.next();\n            System.out.println(menuItem.getName());\n            System.out.println(menuItem.getDescription());\n            System.out.println(menuItem.getVegetarian());\n        }\n    }\n}\n<\/code><\/pre>\n
\n  \u5230\u76ee\u524d\u4e3a\u6b62,\u6211\u4eec\u505a\u4e86\u4e9b\u4ec0\u4e48?<\/p>\n
  \u9996\u5148,\u6211\u4eec\u8ba9\u53a8\u5e08\u4eec\u975e\u5e38\u5feb\u4e50\u3002\u4ed6\u4eec\u53ef\u4ee5\u4fdd\u6301\u4ed6\u4eec\u81ea\u5df1\u7684\u5b9e\u73b0\u53c8\u53ef\u4ee5\u6446\u5e73\u5dee\u522b\u3002\u53ea\u8981\u6211\u4eec\u7ed9\u4ed6\u4eec\u8fd9\u4e24\u4e2a\u8fed\u4ee3\u5668( Pancake Housemenulteratori\u548cDinermenuiterator),\u4ed6\u4eec\u53ea\u9700\u8981\u52a0\u5165\u4e00\u4e2a create Iterator()\u65b9\u6cd5,\u4e00\u5207\u5c31\u5927\u529f\u544a\u6210\u4e86\u3002
\n  \u8fd9\u4e2a\u8fc7\u7a0b\u4e2d,\u6211\u4eec\u4e5f\u5e2e\u4e86\u6211\u4eec\u81ea\u5df1\u3002\u5973\u62db\u5f85\u5c06\u4f1a\u66f4\u5bb9\u6613\u7ef4\u62a4\u548c\u6269\u5c55\u3002\n<\/p><\/blockquote>\n
\u7c7b\u7684\u53d8\u5316<\/h4>\n
\"\"<\/p>\n
\u8fdb\u4e00\u6b65\u5b8c\u5584<\/h4>\n
\u56e0\u4e3aArrayList\u672c\u8eab\u662f\u652f\u6301Iterator\u7684\uff0c\u6240\u4ee5\u76f4\u63a5\u8c03\u7528\u81ea\u8eab\u7684iterator\u65b9\u6cd5\u5373\u53ef<\/p>\n
public Iterator createIterator(){\n        return (Iterator) menuItems.iterator();\n    }\n<\/code><\/pre>\n
\u6211\u4eec\u53ea\u9700\u8981\u7ed9\u83dc\u5355\u4e00\u4e2a\u5171\u540c\u7684\u63a5\u53e3,\u7136\u540e\u518d\u7a0d\u5fae\u6539\u4e00\u4e0b\u5973\u62db\u5f85\u3002\u8fd9\u4e2aMenu\u63a5\u53e3\u76f8\u5f53\u7b80\u5355:\u53ef\u80fd\u9000\u65e9\u9700\u8981\u5728\u91cc\u9762\u591a\u52a0\u5165\u4e00\u4e9b\u65b9\u6cd5,\u4f8b\u5982 ladditem(),\u4f46\u662f\u76ee\u524d,\u6211\u4eec\u8fd8\u662f\u8ba9\u53a8\u5e08\u63a7\u5236\u4ed6\u4eec\u7684\u83dc\u5355,\u4e0d\u8981\u628a\u90a3\u4e9b\u65b9\u6cd5\u653e\u5728\u516c\u5f00\u63a5\u53e3\u4e2d<\/p>\n
public interface Menu {\n    public Iterator createIterator();\n}\n<\/code><\/pre>\n
\u73b0\u5728,\u6211\u4eec\u9700\u8981\u8ba9\u714e\u997c\u5c4b\u83dc\u5355\u7c7b\u548c\u9910\u5382\u83dc\u5355\u7c7b\u90fd\u5b9e\u73b0Menu\u63a5\u53e3,\u7136\u540e\u66f4\u65b0\u5973\u62db\u5f85\u7684\u4ee3\u7801\u5982\u4e0b:<\/p>\n
public class Waitress {\n    Menu pancakeHouseMenu;\n    Menu dinerMenu;\n    public Waitress(Menu pancakeHouseMenu, Menu dinerMenu) {\n        this.pancakeHouseMenu = pancakeHouseMenu;\n        this.dinerMenu = dinerMenu;\n    }\n<\/code><\/pre>\n
\u8fd9\u6837\u6211\u4eec\u5c31\u5b9e\u73b0\u4e86\u9488\u5bf9\u63a5\u53e3\u7f16\u7a0b\uff0c\u800c\u4e0d\u662f\u9488\u5bf9\u5b9e\u73b0\u7f16\u7a0b\u3002<\/p>\n
\u5b8c\u6574\u7684\u7c7b\u56fe\u5c31\u51fa\u73b0\u4e86\uff0c\u6574\u4e2a\u9879\u76ee\u7684\u7ed3\u6784\u5982\u4e0b<\/h4>\n
\"\"<\/p>\n
3.\u8fed\u4ee3\u5668\u6a21\u5f0f\u548c\u5355\u4e00\u804c\u8d23<\/h2>\n
\n  \u8fed\u4ee3\u5668\u6a21\u5f0f\uff1a\u63d0\u4f9b\u4e00\u79cd\u65b9\u6cd5\u987a\u5e8f\u8bbf\u95ee\u4e00\u4e2a\u805a\u5408\u5bf9\u8c61\u4e2d\u7684\u5404\u4e2a\u5143\u7d20\uff0c\u800c\u53c8\u4e0d\u66b4\u9732\u5176\u5185\u90e8\u7684\u8868\u793a\u3002\n<\/p><\/blockquote>\n
\u8fd9\u5f88\u6709\u610f\u4e49:\u8fd9\u4e2a\u6a21\u5f0f\u7ed9\u4f60\u63d0\u4f9b\u4e86\u4e00\u79cd\u65b9\u6cd5,\u53ef\u4ee5\u987a\u5e8f\u8bbf\u95ee\u4e00\u4e2a\u805a\u96c6\u5bf9\u8c61\u4e2d\u7684\u5143\u7d20,\u800c\u53c8\u4e0d\u7528\u77e5\u9053\u5185\u90e8\u662f\u5982\u4f55\u8868\u793a\u7684\u3002\u4f60\u5df2\u7ecf\u5728\u524d\u9762\u7684\u4e24\u4e2a\u83dc\u5355\u5b9e\u73b0\u4e2d\u770b\u5230\u4e86\u8fd9\u4e00\u70b9\u3002\u5728\u8bbe\u8ba1\u4e2d\u4f7f\u7528\u8fed\u4ee3\u5668\u7684\u5f71\u54cd\u662f\u660e\u663e\u7684:\u5982\u679c\u4f60\u6709\u4e00\u4e2a\u7edf\u4e00\u7684\u65b9\u6cd5\u8bbf\u95ee\u805a\u5408\u4e2d\u7684\u6bcf\u4e00\u4e2a\u5bf9\u8c61,\u4f60\u5c31\u53ef\u4ee5\u7f16\u5199\u591a\u6001\u7684\u4ee3\u7801\u548c\u8fd9\u4e9b\u805a\u5408\u642d\u914d,\u4f7f\u7528\u5982\u540c\u524d\u9762\u7684 printmenu\u65b9\u6cd5\u4e00\u6837,\u53ea\u8981\u6709\u4e86\u9001\u4ee3\u5668\u8fd9\u4e2a\u65b9\u6cd5\u6839\u672c\u4e0d\u7ba1\u83dc\u5355\u9879\u7a76\u7adf\u662f\u7531\u6570\u7ec4\u8fd8\u662f\u7531 Arraylist(\u6216\u8005\u5176\u4ed6\u80fd\u521b\u5efa\u8fed\u4ee3\u5668\u7684\u4e1c\u897f)\u6765\u4fdd\u5b58\u7684\u3002
\n\u53e6\u4e00\u4e2a\u5bf9\u4f60\u7684\u8bbe\u8ba1\u9020\u6210\u91cd\u8981\u5f71\u54cd\u7684,\u662f\u8fed\u4ee3\u5668\u6a21\u5f0f\u628a\u5728\u5143\u7d20\u4e4b\u95f4\u6e38\u8d70\u7684\u8d23\u4efb\u4ea4\u7ed9\u8fed\u4ee3\u5668,\u800c\u4e0d\u662f\u805a\u5408\u5bf9\u8c61\u3002<\/strong>
\n\u8fd9\u4e0d\u4ec5\u8ba9\u805a\u5408\u7684\u63a5\u53e3\u548c\u5b9e\u73b0\u53d8\u5f97\u66f4\u7b80\u6d01,\u4e5f\u53ef\u4ee5\u8ba9\u805a\u5408\u66f4\u4e13\u6ce8\u5728\u5b83\u6240\u5e94\u8be5\u4e13\u6ce8\u7684\u4e8b\u60c5\u4e0a\u9762(\u4e5f\u5c31\u662f\u7ba1\u7406\u5bf9\u8c61\u96c6\u5408),\u800c\u4e0d\u5fc5\u53bb\u7406\u4f1a\u904d\u5386\u7684\u4e8b\u60c5<\/p>\n
\n  \u8fed\u4ee3\u5668\u6a21\u5f0f\u8ba9\u6211\u4eec\u80fd\u6e38\u8d70\u4e8e\u805a\u5408\u5185\u7684\u6bcf\u4e00\u4e2a\u5143\u7d20,\u800c\u53c8\u4e0d\u66b4\u9732\u5176\u5185\u90e8\u7684\u8868\u793a\u3002
\n  \u628a\u6e38\u8d70\u7684\u4efb\u52a1\u653e\u5728\u8fed\u4ee3\u5668\u4e0a,\u800c\u4e0d\u662f\u805a\u5408\u4e0a\u3002
\n  \u8fd9\u6837\u7b80\u5316\u4e86\u805a\u5408\u7684\u63a5\u548c\u7a81\u73b0,\u4e5f\u8ba9\u8d23\u4efb\u5404\u5f97\u5176\u6240\u3002\n<\/p><\/blockquote>\n
\u5355\u4e00\u804c\u8d23<\/h4>\n
\n  \u8bbe\u8ba1\u539f\u5219\uff1a\u4e00\u4e2a\u7c7b\u5e94\u8be5\u53ea\u6709\u4e00\u4e2a\u5f15\u8d77\u53d8\u5316\u7684\u539f\u56e0\u3002\n<\/p><\/blockquote>\n
\u7c7b\u7684\u6bcf\u4e2a\u8d23\u4efb\u90fd\u6709\u6539\u53d8\u7684\u6f5c\u5728\u533a\u57ce\u3002\u8d85\u8fc7\u4e2a\u8d23\u4efb,\u610f\u5473\u7740\u8d85\u8fc7\u4e2a\u6539\u53d8\u7684\u533a\u57df\u3002
\n\u8fd9\u4e2a\u539f\u5219\u544a\u8bc9\u6211\u4eec\u91cf\u8ba9\u6bcf\u4e2a\u7c7b\u4fdd\u6301\u5355\u4e00\u8d23\u4efb\u3002<\/p>\n
4.\u65b0\u52a0\u5165\u7684\u5496\u5561\u5e97<\/h2>\n
\u65b0\u7684\u9700\u6c42\u51fa\u73b0\u4e86\uff0c\u5496\u5561\u5e97\u4e5f\u52a0\u5165\u4e86\u8fd9\u4efd\u83dc\u5355\u4e2d\uff0c\u8981\u5c06\u5b83\u4eec\u7ee7\u7eed\u6574\u5408\u5728\u4e00\u4e2a\u6846\u67b6\u4e2d\u3002<\/p>\n
\u5148\u770b\u5496\u5561\u5385\u7684\u4ee3\u7801\uff0c\u5df2\u7ecf\u5c06\u4e4b\u524d\u7684\u63a5\u53e3\u52a0\u4e86\u8fdb\u53bb<\/p>\n
public class CafeMenu implements Menu {\n    Hashtable menuItems = new Hashtable();\n\n    public CafeMenu() {\n        addItem(\"Veggie Burger and Air Fries\",\n                \"Veggie burger on a whole wheat bun , lettuce,tomato , and fries\",\n                true,3.99);\n    }\n    private void addItem(String name, String description, boolean vegetarian, double price) {\n        MenuItem menuItem = new MenuItem(name, description, vegetarian, price);\n        menuItems.put(menuItem.getName(),menuItem);\n    }\n    public Iterator createIterator() {\n        return (Iterator) menuItems.values().iterator();\n    }\n}\n<\/code><\/pre>\n
\u4fee\u6539\u5973\u62db\u5f85\u7684\u4ee3\u7801<\/p>\n
public class Waitress {\n    Menu pancakeHouseMenu;\n    Menu dinerMenu;\n    Menu cafeMenu;\n    public Waitress(Menu pancakeHouseMenu, Menu dinerMenu,Menu cafeMenu) {\n        this.pancakeHouseMenu = pancakeHouseMenu;\n        this.dinerMenu = dinerMenu;\n        this.cafeMenu = cafeMenu;\n    }\n    public void printMenu(){\n        Iterator pancakeHouseMenuIterator = pancakeHouseMenu.createIterator();\n        Iterator dinerMenuIterator = dinerMenu.createIterator();\n        Iterator cafeMenuIterator = cafeMenu.createIterator();\n        printMenu(pancakeHouseMenuIterator);\n        printMenu(dinerMenuIterator);\n        printMenu(cafeMenuIterator);\n    }\n    private void printMenu(Iterator iterator) {\n        while (iterator.hasNext()){\n            MenuItem menuItem = (MenuItem) iterator.next();\n            System.out.println(menuItem.getName());\n            System.out.println(menuItem.getDescription());\n            System.out.println(menuItem.getVegetarian());\n        }\n    }\n}\n<\/code><\/pre>\n
\u8fd9\u6837\u5c31\u52a0\u5165\u4e86\u65b0\u7684\u5496\u5561\u5385\u83dc\u5355<\/p>\n
\u4f46\u662f\uff0c\u8fd9\u6837\u7a0b\u5e8f\u4e2d\u8fd8\u662f\u8c03\u7528\u4e86\u4e09\u6b21printMenu\u65b9\u6cd5\uff0c\u800c\u4e14\u6bcf\u6b21\u6709\u65b0\u7684\u83dc\u5355\u52a0\u5165\uff0c\u90fd\u5fc5\u987b\u6253\u5f00\u5973\u62db\u5f85\u52a0\u5165\u66f4\u591a\u7684\u4ee3\u7801\uff0c\u597d\u50cf\u8fdd\u53cd\u4e86\u5f00\u653e-\u5173\u95ed\u539f\u5219\u3002<\/h4>\n
\u8fd9\u6b21\u5c06\u8fd9\u4e9b\u83dc\u5355\u5168\u90fd\u6253\u5305\u8fdb\u4e00\u4e2a Arraylist,\u7136\u540e\u53d6\u5f97\u5b83\u7684\u8fed\u4ee3\u5668,\u904d\u5386\u6bcf\u4e00\u4e2a\u83dc\u5355\u3002\u8fd9\u6837\u518d\u589e\u52a0\u83dc\u5355\u4e5f\u4e0d\u6015\u4e86\u3002<\/p>\n
public class Waitress {\n    ArrayList menus;\n    public Waitress(ArrayList menus) {\n        this.menus = menus;\n    }\n    public void printMenu(){\n        Iterator iterator = (Iterator) menus.iterator();\n        while (iterator.hasNext()){\n            Menu menu = (Menu) iterator.next();\n            printMenu(menu.createIterator());\n        }\n\n    }\n    private void printMenu(Iterator iterator) {\n        while (iterator.hasNext()){\n            MenuItem menuItem = (MenuItem) iterator.next();\n            System.out.println(menuItem.getName());\n            System.out.println(menuItem.getDescription());\n            System.out.println(menuItem.getVegetarian());\n        }\n    }\n}\n<\/code><\/pre>\n
\u6700\u540e\u5c31\u5168\u90e8\u5b8c\u6210\u4e86\uff0c\u5f7b\u5e95\u89e3\u8026\u4e86\u3002<\/h4>\n
5.\u6dfb\u52a0\u4e00\u4efd\u5b50\u83dc\u5355<\/h2>\n
\u6211\u4eec\u9700\u8981\u5728\u9910\u5385\u83dc\u5355\u4e2d\u6dfb\u52a0\u4e00\u4efd\u751c\u70b9\u5b50\u83dc\u5355\uff0c\u8fd9\u5c31\u9700\u8981\u652f\u6301\u83dc\u5355\u4e2d\u7684\u83dc\u5355\u4e86\u3002<\/p>\n
\u5982\u4e0b\u56fe\uff0c\u6b63\u662f\u6211\u4eec\u60f3\u8981\u7684\u6837\u5b50\u3002<\/p>\n
\"\"<\/p>\n
\u4f46\u6211\u4eec\u4e0d\u80fd\u628a\u751c\u70b9\u83dc\u5355\u8d4b\u503c\u7ed9\u83dc\u5355\u9879\u6570\u7ec4\u3002<\/p>\n
\u8fd9\u65f6\u5019\u5c31\u9700\u8981\u91cd\u6784\u4e86<\/p>\n
\u4e8b\u5b9e\u662f\uff0c\u6211\u4eec\u5df2\u7ecf\u5230\u8fbe\u4e86\u4e00\u4e2a\u590d\u6742\u7ea7\u522b\uff0c\u5982\u679c\u73b0\u5728\u4e0d\u91cd\u65b0\u8bbe\u8ba1\uff0c\u5c31\u65e0\u6cd5\u5bb9\u7eb3\u672a\u6765\u589e\u52a0\u7684\u83dc\u5355\u6216\u5b50\u83dc\u5355\u7b49\u9700\u6c42\u3002
\n\u6240\u4ee5\uff0c\u5728\u6211\u4eec\u7684\u65b0\u8bbe\u8ba1\u4e2d\uff0c\u771f\u6b63\u9700\u8981\u4e9b\u4ec0\u4e48\u5462?<\/p>\n
    \n
  • \u6211\u4eec\u9700\u8981\u67d0\u79cd\u6811\u5f62\u7ed3\u6784\uff0c\u53ef\u4ee5\u5bb9\u7eb3\u83dc\u5355\u3001\u5b50\u83dc
    \n\u5355\u548c\u83dc\u5355\u9879\u3002<\/li>\n
  • \u6211\u4eec\u9700\u8981\u786e\u5b9a\u80fd\u591f\u5728\u6bcf\u4e2a\u83dc\u5355\u7684\u5404\u4e2a\u9879\u4e4b\u95f4\u6e38:
    \n\u8d70\uff0c\u800c\u4e14\u81f3\u5c11\u8981\u50cf\u73b0\u5728\u7528\u8fed\u4ee3\u5668\u4e00-\u6837\u65b9\u4fbf\u3002<\/li>\n
  • \u6211\u4eec\u4e5f\u9700\u8981\u80fd\u591f\u66f4\u6709\u5f39\u6027\u5730\u5728\u83dc\u5355\u9879\u4e4b\u95f4\u6e38\u8d70\u3002
    \n\u6bd4\u65b9\u8bf4\uff0c\u53ef\u80fd\u53ea\u9700\u8981\u904d\u5386\u751c\u70b9\u83dc\u5355\uff0c\u6216\u8005\u53ef\u4ee5
    \n\u904d\u5386\u9910\u5385\u7684\u6574\u4e2a\u83dc\u5355( \u5305\u62ec\u751c\u70b9\u83dc\u5355\u5728\u5185)\u3002<\/li>\n<\/ul>\n
    6. \u7ec4\u5408\u6a21\u5f0f<\/h2>\n
    \u6211\u4eec\u8981\u4ecb\u7ecd\u53e6\u4e00\u4e2a\u6a21\u5f0f\u89e3\u51b3\u8fd9\u4e2a\u96be\u9898\u3002\u6211\u4eec\u5e76\u6ca1\u6709\u653e\u5f03\u8fed\u4ee3\u5668\u4e00\u4e00\u5b83\u4ecd\u7136\u662f\u6211\u4eec\u89e3\u6c7a\u65b9\u6848\u4e2d\u7684\u4e00\u90e8\u5206\uff0c\u7136\u800c,\u7ba1\u7406\u83dc\u5355\u7684\u95ee\u9898\u5df2\u7ecf\u5230\u4e86\u4e00\u4e2a\u8fed\u4ee3\u5668\u65e0\u6cd5\u89e3\u51b3\u7684\u65b0\u7ef4\u5ea6\u3002\u6240\u4ee5,\u6211\u4eec\u5c06\u5012\u9000\u51e0\u6b65,\u6539\u7528\u7ec4\u5408\u6a21\u5f0f( Composite Pattern)\u6765\u5b9e\u73b0\u8fd9\u4e00\u90e8\u5206\u3002<\/p>\n
    \n  \u7ec4\u5408\u6a21\u5f0f\uff1a\u5141\u8bb8\u4f60\u5c06\u5bf9\u8c61\u7ec4\u5408\u6210\u6811\u5f62\u7ed3\u6784\u6765\u8868\u73b0\u201c\u6574\u4f53\/\u90e8\u5206\u201d\u5c42\u6b21\u7ed3\u6784\u3002\u7ec4\u5408\u80fd\u8ba9\u5ba2\u6237\u4ee5\u4e00\u81f4\u7684\u65b9\u5f0f\u5904\u7406\u4e2a\u522b\u5bf9\u8c61\u4ee5\u53ca\u5bf9\u8c61\u7ec4\u5408\u3002\n<\/p><\/blockquote>\n
    \u7ec4\u5408\u6a21\u5f0f\u8ba9\u6211\u4eec\u80fd\u7528\u6811\u5f62\u65b9\u5f0f\u521b\u5efa\u5bf9\u8c61\u7684\u7ed3,\u6811\u91cc\u9762\u5305\u542b\u4e86\u7ec4\u5408\u4ee5\u53ca\u4e2a\u522b\u7684\u5bf9\u8c61\u3002<\/p>\n
    \u4f7f\u7ec4\u5408\u7ed3\u6784,\u6211\u4eec\u80fd\u628a\u76f8\u540c\u7684\u64cd\u4f5c\u5e94\u7528\u5728\u7ec4\u5408\u548c\u4e2a\u522b\u5bf9\u8c61\u4e0a\u3002\u6362\u53e5\u8bdd\u8bf4,\u5728\u5927\u591a\u6570\u60c5\u6cc1\u4e0b, \u6211\u4eec\u53ef\u4ee5\u5ffd\u7565\u5bf9\u8c61\u7ec4\u5408\u548c\u4e2a\u522b\u5bf9\u8c61\u4e4b\u95f4\u7684\u5dee\u522b\u3002<\/p>\n
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    \n\u4e14\u6709\u4e86\u4e30\u5bcc\u7684\u5927\u83dc\u5355,\u6211\u4eec\u5c31\u53ef\u4ee5\u4f7f\u7528\u8fd9\u4e2a\u6a21\u5f0f\u6765\u201c\u7edf\u4e00\u5904\u7406\u4e2a\u522b\u5bf9\u8c61\u548c\u7ec4\u5408\u5bf9\u8c61\u201d\u3002\u8fd9\u610f\u5473\u7740\u4ec0\u4e48? \u5b83\u610f\u5473\u7740,\u5982\u679c\u6211\u4eec\u6709\u4e86\u4e00\u4e2a\u6811\u5f62\u7ed3\u6784\u7684\u83dc\u5355\u3001\u5b50\u83dc\u5355\u548c\u53ef\u80fd\u8fd8\u5e26\u6709\u83dc\u5355\u9879\u7684\u5b50\u83dc\u5355,\u90a3\u4e48\u4efb\u4f55\u4e00\u4e2a\u83dc\u5355\u90fd\u662f\u79cd\u201c\u7ec4\u5408\u201d\u3002\u56e0\u4e3a\u5b83\u65e2\u53ef\u4ee5\u5305\u542b\u5176\u4ed6\u83dc\u5355,\u4e5f\u53ef\u4ee5\u5305\u542b\u83dc\u5355\u9879\u3002\u4e2a\u522b\u5bf9\u8c61\u53ea\u662f\u83dc\u5355\u9879\u4e00\u4e00\u5e76\u672a\u6301\u6709\u5176\u4ed6\u5bf9\u8c61\u3002
    \n\u5c31\u50cf\u4f60\u5c06\u770b\u5230\u7684,\u4f7f\u7528\u4e00\u4e2a\u9075\u7167\u7ec4\u5408\u6a21\u5f0f\u7684\u8bbe\u8ba1,\u8ba9\u6211\u4eec\u80fd\u591f\u5199\u51fa\u7b80\u5355\u7684\u4ee3\u7801,\u5c31\u80fd\u591f\u5bf9\u6574\u4e2a\u83dc\u5355\u7ed3\u6784\u5e94\u7528\u76f8\u540c\u7684\u64cd\u4f5c(\u4f8b\u5982\u6253\u5370!)\u3002<\/p>\n
    7.\u4f7f\u7528\u7ec4\u5408\u6a21\u5f0f\u8bbe\u8ba1\u83dc\u5355<\/h2>\n
    \u6211\u4eec\u8981\u5982\u4f55\u5728\u83dc\u5355\u4e0a\u5e94\u7528\u7ec4\u5408\u6a21\u5f0f\u5462?\u4e00\u5f00\u59cb,\u6211\u4eec\u9700\u8981\u521b\u5efa\u4e00\u4e2a\u7ec4\u4ef6\u63a5\u53e3\u6765\u4f5c\u4e3a\u83dc\u5355\u548c\u83dc\u5355\u9879\u7684\u5171\u540c\u63a5\u53e3,\u8ba9\u6211\u4eec\u80fd\u591f\u7528\u7edf\u4e00\u7684\u505a\u6cd5\u6765\u5904\u7406\u83dc\u5355\u548c\u83dc\u5355\u9879\u3002\u6362\u53e5\u8bdd\u8bf4,\u6211\u4eec\u53ef\u4ee5\u9488\u5bf9\u5355\u6216\u83dc\u5355\u9879\u8c03\u7528\u76f8\u540c\u7684\u65b9\u6cd5\u3002<\/p>\n
    \u5b9e\u73b0\u83dc\u5355\u7ec4\u4ef6<\/h4>\n
    \u597d\u4e86,\u6211\u4eec\u8981\u5f00\u59cb\u7f16\u5199\u83dc\u5355\u7ec4\u4ef6\u7684\u62bd\u8c61\u7c7b;\u8bf7\u8bb0\u4f4f,\u83dc\u5355\u7ec4\u4ef6\u7684\u89d2\u8272\u662f\u4e3a\u53f6\u8282\u70b9\u548c\u7ec4\u5408\u8282\u70b9\u63d0\u4f9b\u4e00\u4e2a\u5171\u540c\u7684\u63a5\u53e3\u3002\u73b0\u5728\u4f60\u53ef\u80fd\u60f3\u95ee:\u201c\u90a3\u4e48\u83dc\u5355\u7ec4\u4ef6\u4e0d\u5c31\u626e\u6f14\u4e86\u4e24\u4e2a\u89d2\u8272\u5417?\u201d\u53ef\u80fd\u662f\u8fd9\u6837\u7684,\u6211\u4eec\u7a0d\u540e\u518d\u8ba8\u8bba\u8fd9\u4e00\u70b9\u3002\u7136\u800c,\u76ee\u524d\u6211\u4eec\u8981\u4e3a\u8fd9\u4e9b\u65b9\u6cd5\u63d0\u4f9b\u9ed8\u8ba4\u7684\u5b9e\u73b0,\u8fd9\u6837,\u5982\u679c\u83dc\u5355\u9879(\u53f6\u8282\u70b9)\u6216\u8005\u83dc\u5355(\u7ec4\u5408)\u4e0d\u60f3\u5b9e\u73b0\u67d0\u4e9b\u65b9\u6cd5\u7684\u65f6\u5019(\u4f8b\u5982\u53f6\u8282\u70b9\u4e0d\u60f3\u5b9e\u73b0getchild\u65b9\u6cd5),\u5c31\u53ef\u4ee5\u4e0d\u5b9e\u73b0\u8fd9\u4e9b\u65b9\u6cd5\u3002<\/p>\n
    \n  \u6240\u6709\u7684\u7ec4\u4ef6\u90fd\u5fc5\u987b\u5b9e\u73b0Menu Component\u63a5\u53e3; \u7136\u800c,\u53f6\u8282\u70b9\u548c\u7ec4\u5408\u8282\u70b9\u7684\u89d2\u8272\u4e0d\u540c,\u6240\u4ee5\u6709\u4e9b\u65b9\u6cd5\u53ef\u80fd\u5e76\u4e0d\u9002\u5408\u67d0\u79cd\u8282\u70b9\u3002\u9762\u5bf9\u8fd9\u79cd\u60c5\u51b5,\u6709\u65f6\u5019,\u4f60\u6700\u597d\u662f\u629b\u51fa\u8fd0\u884c\u65f6\u5f02\u5e38\u3002\n<\/p><\/blockquote>\n
    public abstract class MenuComponent {\n    public void add(MenuComponent menuComponent){\n        throw new UnsupportedOperationException();\n    }\n    public void remove(MenuComponent menuComponent){\n        throw new UnsupportedOperationException();\n    }\n    public MenuComponent getChild(int i){\n        throw new UnsupportedOperationException();\n    }\n    public String getName(){\n        throw new UnsupportedOperationException();\n    }\n    public String getDescription(){\n        throw new UnsupportedOperationException();\n    }\n    public double getPrice(){\n        throw new UnsupportedOperationException();\n    }\n    public boolean isVegetarian(){\n        throw new UnsupportedOperationException();\n    }\n    public void print(){\n        throw new UnsupportedOperationException();\n    }\n\n}\n<\/code><\/pre>\n
    \u5b9e\u73b0\u83dc\u5355\u9879<\/h4>\n
    public class MenuItem extends MenuComponent {\n    String name;\n    String description;\n    boolean vegetarian;\n    double price;\n\n    public MenuItem(String name, String description, boolean vegetarian, double price) {\n        this.name = name;\n        this.description = description;\n        this.vegetarian = vegetarian;\n        this.price = price;\n    }\n\n    @Override\n    public String getName() {\n        return name;\n    }\n\n    @Override\n    public String getDescription() {\n        return description;\n    }\n\n    @Override\n    public boolean isVegetarian() {\n        return vegetarian;\n    }\n\n    @Override\n    public double getPrice() {\n        return price;\n    }\n    public void print(){\n        System.out.println(\"\"+getName());\n        System.out.println(getPrice());\n        System.out.println(getDescription());\n    }\n}\n\n<\/code><\/pre>\n
    \u5b9e\u73b0\u7ec4\u5408\u83dc\u5355<\/h4>\n
    public class Menu extends MenuComponent {\n    ArrayList menuComponents = new ArrayList();\n    String name;\n    String description;\n\n    public Menu(String name, String description) {\n        this.name = name;\n        this.description = description;\n    }\n\n    @Override\n    public void add(MenuComponent menuComponent) {\n        menuComponents.add(menuComponent);\n    }\n\n    @Override\n    public void remove(MenuComponent menuComponent) {\n        menuComponents.remove(menuComponent);\n    }\n\n    @Override\n    public MenuComponent getChild(int i) {\n        return (MenuComponent) menuComponents.get(i);\n    }\n\n    @Override\n    public String getName() {\n        return name;\n    }\n\n    @Override\n    public String getDescription() {\n        return description;\n    }\n\n    @Override\n    public void print() {\n\/\/        \u8fd9\u91cc\u4f7f\u7528\u9012\u5f52\u7684\u65b9\u5f0f\uff0c\u5c06\u6240\u6709\u7684\u5b50\u83dc\u5355\u4e5f\u6253\u5370\u51fa\u6765\n        System.out.println(getName());\n        System.out.println(getDescription());\n        Iterator iterator = menuComponents.iterator();\n        while (iterator.hasNext()){\n            MenuComponent menuComponent = (MenuComponent) iterator.next();\n            menuComponent.print();\n        }\n    }\n}\n<\/code><\/pre>\n
    \u6700\u540e\u6211\u4eec\u66f4\u65b0\u5973\u62db\u5f85\u7684\u4ee3\u7801\uff0c\u8ba9\u5979\u6765\u6253\u5370\u83dc\u5355<\/h4>\n
    public class Waitress {\n    MenuComponent allMenus;\n\n    public Waitress(MenuComponent allMenus) {\n        this.allMenus = allMenus;\n    }\n    public void printMent(){\n        allMenus.print();\n    }\n}\n<\/code><\/pre>\n
    \u5973\u62db\u5f85\u7684\u4ee3\u7801\u53d8\u5f97\u5f88\u7b80\u5355\uff0c\u5979\u53ea\u8981\u8c03\u7528\u6700\u9876\u5c42\u7684\u7ec4\u4ef6\uff0c\u5c31\u53ef\u4ee5\u6253\u5370\u6574\u4e2a\u83dc\u5355\u5c42\u6b21\uff0c\u592a\u68d2\u4e86\u3002<\/p>\n
    \u7f16\u5199\u6d4b\u8bd5\u7a0b\u5e8f<\/h4>\n
    public class MenuTestDrive {\n    public static void main(String[] args) {\n        MenuComponent pancakeHouseMenu = new Menu(\"PANCAKE HOUSE MENU\",\"Breakfast\");\n        MenuComponent dinerMenu = new Menu(\"DINER MENU\",\"Lunch\");\n        MenuComponent cafeMenu = new Menu(\"CAFE MENU\",\"Dinner\");\n        MenuComponent dessertMenu = new Menu(\"DESSERT MENU\",\"Dessert of course!\");\n        MenuComponent allMenus = new Menu(\"ALL MENUS\",\"ALL menus combined\");\n        allMenus.add(pancakeHouseMenu);\n        allMenus.add(dessertMenu);\n        allMenus.add(dinerMenu);\n        dinerMenu.add(new MenuItem(\n                \"Pasta\",\n                \"Spaghetti with Marinara Sauce ,and a slice of sourdough bread\",\n                true,\n                3.89\n        ));\n        dinerMenu.add(dessertMenu);\n        dessertMenu.add(new MenuItem(\n                \"Apple Pie\",\n                \"Apple pie with a flakey crust, topped with vanilla ice cream\",\n                true,\n                1.59\n        ));\n        Waitress waitress = new Waitress(allMenus);\n        waitress.printMent();\n    }\n}\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
    \u300aHeadFirst\u8bbe\u8ba1\u6a21\u5f0f\u300b\u7b2c\u4e5d\u7ae0\u8fed\u4ee3\u5668\u4e0e\u7ec4\u5408\u6a21\u5f0f-\u8bfb\u4e66\u7b14\u8bb0 \u6848\u4f8b\u4ee3\u7801\u94fe\u63a5\uff1ahttps:\/\/github.c\u2026 Read More »<\/a><\/span><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[],"class_list":["post-1099","post","type-post","status-publish","format-standard","hentry","category-23"],"_links":{"self":[{"href":"http:\/\/rain1024.com\/index.php\/wp-json\/wp\/v2\/posts\/1099","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/rain1024.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/rain1024.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/rain1024.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/rain1024.com\/index.php\/wp-json\/wp\/v2\/comments?post=1099"}],"version-history":[{"count":1,"href":"http:\/\/rain1024.com\/index.php\/wp-json\/wp\/v2\/posts\/1099\/revisions"}],"predecessor-version":[{"id":1364,"href":"http:\/\/rain1024.com\/index.php\/wp-json\/wp\/v2\/posts\/1099\/revisions\/1364"}],"wp:attachment":[{"href":"http:\/\/rain1024.com\/index.php\/wp-json\/wp\/v2\/media?parent=1099"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/rain1024.com\/index.php\/wp-json\/wp\/v2\/categories?post=1099"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/rain1024.com\/index.php\/wp-json\/wp\/v2\/tags?post=1099"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}