{"id":259,"date":"2026-07-17T18:26:31","date_gmt":"2026-07-17T10:26:31","guid":{"rendered":"http:\/\/ssjava.xyz\/?p=259"},"modified":"2026-07-17T11:26:21","modified_gmt":"2026-07-17T03:26:21","slug":"16-%e7%bb%a7%e6%89%bf%e4%bd%93%e7%b3%bb%e8%ae%be%e8%ae%a1%e5%ae%9e%e6%88%98%ef%bc%9a%e9%87%8c%e6%b0%8f%e6%9b%bf%e6%8d%a2%e5%8e%9f%e5%88%99%e4%b8%8e%e7%bb%84%e5%90%88%e4%bc%98%e5%85%88","status":"publish","type":"post","link":"https:\/\/ssjava.xyz\/index.php\/2026\/07\/17\/16-%e7%bb%a7%e6%89%bf%e4%bd%93%e7%b3%bb%e8%ae%be%e8%ae%a1%e5%ae%9e%e6%88%98%ef%bc%9a%e9%87%8c%e6%b0%8f%e6%9b%bf%e6%8d%a2%e5%8e%9f%e5%88%99%e4%b8%8e%e7%bb%84%e5%90%88%e4%bc%98%e5%85%88\/","title":{"rendered":"16. \u7ee7\u627f\u4f53\u7cfb\u8bbe\u8ba1\u5b9e\u6218\uff1a\u91cc\u6c0f\u66ff\u6362\u539f\u5219\u4e0e\u7ec4\u5408\u4f18\u5148"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">\u7ecf\u8fc7\u524d\u4e09\u7bc7\u7684\u5b66\u4e60\uff0c\u4f60\u5df2\u7ecf\u638c\u63e1\u4e86\u7ee7\u627f\u7684\u8bed\u6cd5\u3001<code>super<\/code> \u548c\u6784\u9020\u5668\u94fe\u3001\u65b9\u6cd5\u91cd\u5199\u4e0e <code>final<\/code> \u5173\u952e\u5b57\u7684\u7528\u6cd5\u3002\u4f46\u638c\u63e1\u8bed\u6cd5\u53ea\u662f\u7b2c\u4e00\u6b65\u2014\u2014\u771f\u6b63\u5230\u5199\u5de5\u7a0b\u4ee3\u7801\u7684\u65f6\u5019\uff0c\u4f60\u53ef\u80fd\u4f1a\u7ea0\u7ed3\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u300c\u8fd9\u4e2a\u573a\u666f\u7528\u7ee7\u627f\u5408\u9002\u5417\uff1f\u300d<\/li>\n\n\n\n<li>\u300c\u4e24\u4e2a\u7c7b\u6709\u5171\u540c\u4ee3\u7801\uff0c\u6211\u8be5\u4e0d\u8be5\u62bd\u4e00\u4e2a\u7236\u7c7b\u51fa\u6765\uff1f\u300d<\/li>\n\n\n\n<li>\u300c\u600e\u4e48\u8bbe\u8ba1\u7ee7\u627f\u5c42\u6b21\u624d\u4e0d\u81f3\u4e8e\u540e\u671f\u6539\u4e0d\u52a8\uff1f\u300d<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u4e00\u7bc7\u6211\u4eec\u5c31\u6765\u505a\u300c\u8bbe\u8ba1\u5c42\u9762\u300d\u7684\u6536\u5c3e\u3002\u901a\u8fc7\u7efc\u5408\u5b9e\u6218\u6848\u4f8b\uff0c\u5f15\u51fa\u91cd\u8981\u7684<strong>\u91cc\u6c0f\u66ff\u6362\u539f\u5219<\/strong>\uff0c\u5e76\u4e14\u597d\u597d\u804a\u804a\u4e1a\u754c\u5e38\u7528\u7684\u90a3\u53e5\u8bdd\u2014\u2014<strong>\u300c\u4f18\u5148\u4f7f\u7528\u7ec4\u5408\u800c\u975e\u7ee7\u627f\u300d<\/strong>\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u4e00\u3001\u91cc\u6c0f\u66ff\u6362\u539f\u5219\uff08Liskov Substitution Principle, LSP\uff09<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u662f\u9762\u5411\u5bf9\u8c61\u8bbe\u8ba1\u4e94\u5927\u539f\u5219\uff08SOLID\uff09\u4e2d\u7684 L\u3002Barbara Liskov \u5728 1987 \u5e74\u63d0\u51fa\u4e86\u5b83\uff0c\u6838\u5fc3\u601d\u60f3\u7528\u4e00\u53e5\u8bdd\u8bf4\u5c31\u662f\uff1a<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>\u4efb\u4f55\u4f7f\u7528\u7236\u7c7b\u5bf9\u8c61\u7684\u5730\u65b9\uff0c\u90fd\u80fd\u900f\u660e\u5730\u66ff\u6362\u4e3a\u5b50\u7c7b\u5bf9\u8c61\uff0c\u7a0b\u5e8f\u7684\u884c\u4e3a\u4e0d\u4f1a\u51fa\u9519\u3002<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">\u542c\u8d77\u6765\u5f88\u7b80\u5355\uff1f\u770b\u770b\u8fd9\u4e2a\u7ecf\u5178\u7684\u53cd\u9762\u6848\u4f8b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\/\/ \u274c \u8fdd\u53cd\u91cc\u6c0f\u66ff\u6362\u539f\u5219\u7684\u7ecf\u5178\u6848\u4f8b\nclass Rectangle {\n    protected int width;\n    protected int height;\n\n    public void setWidth(int width) { this.width = width; }\n    public void setHeight(int height) { this.height = height; }\n    public int getArea() { return width * height; }\n}\n\nclass Square extends Rectangle {\n    @Override\n    public void setWidth(int width) {\n        this.width = width;\n        this.height = width; \/\/ \u6b63\u65b9\u5f62\u5fc5\u987b\u4fdd\u6301\u8fb9\u76f8\u7b49\n    }\n\n    @Override\n    public void setHeight(int height) {\n        this.width = height;\n        this.height = height;\n    }\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u770b\u8d77\u6765\u633a\u5408\u7406\u2014\u6b63\u65b9\u5f62\u662f\u7279\u6b8a\u7684\u77e9\u5f62\uff0c\u5bf9\u5427\uff1f\u4f46\u770b\u770b\u8fd9\u4e2a\u4ee3\u7801\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>void resize(Rectangle r) {\n    r.setWidth(5);\n    r.setHeight(10);\n    \/\/ \u671f\u671b\u9762\u79ef = 50\n    assert r.getArea() == 50;\n}\n\npublic class Main {\n    public static void main(String&#91;] args) {\n        Rectangle rect = new Rectangle();\n        resize(rect); \/\/ \u2705 \u9762\u79ef = 50\n\n        Rectangle square = new Square();\n        resize(square); \/\/ \u274c \u9762\u79ef = 100\uff01\u6b63\u65b9\u5f62\u88ab\u6491\u574f\u4e86\n    }\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Square \u66ff\u6362 Rectangle \u540e\uff0c<code>resize()<\/code> \u65b9\u6cd5\u7684\u884c\u4e3a\u51fa\u9519\u4e86\u3002\u8fd9\u8fdd\u53cd\u4e86\u91cc\u6c0f\u66ff\u6362\u539f\u5219\u2014\u2014\u56e0\u4e3a <code>Square<\/code> \u6539\u53d8\u4e86 <code>setWidth<\/code> \u548c <code>setHeight<\/code> \u7684&#8221;\u8bed\u4e49&#8221;\uff0c\u8c03\u7528\u8005\u6ca1\u60f3\u5230\u8bbe\u7f6e\u5bbd\u5ea6\u8fd8\u4f1a\u6539\u53d8\u9ad8\u5ea6\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u4e5f\u63ed\u793a\u4e86\u4e00\u4e2a\u6df1\u523b\u7684\u9053\u7406\uff1a<strong>\u7ee7\u627f\u4e0d\u53ea\u662f\u4ee3\u7801\u590d\u7528\uff0c\u66f4\u662f\u300cis-a\u300d\u5173\u7cfb\u7684\u5efa\u6a21<\/strong>\u3002\u300c\u6b63\u65b9\u5f62 is-a \u77e9\u5f62\u300d\u5728\u6570\u5b66\u4e0a\u6210\u7acb\uff0c\u4f46\u5728\u53ef\u53d8\u5bf9\u8c61\u7684\u573a\u666f\u4e0b\u2014\u2014\u4f60\u8981\u7684\u4e0d\u662f\u5f62\u72b6\u7684\u9759\u6001\u5173\u7cfb\uff0c\u800c\u662f\u884c\u4e3a\u7684\u66ff\u6362\u80fd\u529b\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">LSP \u7684\u51e0\u6761\u5224\u65ad\u6807\u51c6<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u5b50\u7c7b\u4e0d\u80fd\u5f3a\u5316\u7236\u7c7b\u7684\u524d\u7f6e\u6761\u4ef6<\/strong>\uff08\u6bd4\u5982\u7236\u7c7b\u65b9\u6cd5\u63a5\u6536\u6b63\u6574\u6570\uff0c\u5b50\u7c7b\u4e0d\u80fd\u8981\u6c42\u5fc5\u987b\u5927\u4e8e 100\uff09<\/li>\n\n\n\n<li><strong>\u5b50\u7c7b\u4e0d\u80fd\u5f31\u5316\u7236\u7c7b\u7684\u540e\u7f6e\u6761\u4ef6<\/strong>\uff08\u6bd4\u5982\u7236\u7c7b\u65b9\u6cd5\u4fdd\u8bc1\u8fd4\u56de\u975e\u7a7a\uff0c\u5b50\u7c7b\u4e0d\u80fd\u8fd4\u56de null\uff09<\/li>\n\n\n\n<li><strong>\u5b50\u7c7b\u4e0d\u80fd\u6539\u53d8\u7236\u7c7b\u65b9\u6cd5\u7684\u300c\u9884\u671f\u884c\u4e3a\u300d<\/strong>\uff08\u5c31\u50cf Square \u6539\u4e86 setWidth \u7684\u9884\u671f\uff09<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u4e8c\u3001\u4f55\u65f6\u8be5\u7528\u7ee7\u627f\uff1f<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u91cc\u6c0f\u66ff\u6362\u539f\u5219\u7ed9\u4e86\u6211\u4eec\u4e00\u4e2a\u5f88\u597d\u7684\u68c0\u9a8c\u6807\u51c6\uff1a\u7528\u7ee7\u627f\u65f6\uff0c\u95ee\u81ea\u5df1\u4e09\u4e2a\u95ee\u9898\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u5b50\u7c7b\u771f\u7684\u662f\u7236\u7c7b\u7684\u4e00\u79cd\u5417\uff1f<\/strong>\uff08\u771f\u6b63\u7684 is-a \u5173\u7cfb\uff09<\/li>\n\n\n\n<li><strong>\u5b50\u7c7b\u80fd\u5b8c\u5168\u66ff\u4ee3\u7236\u7c7b\u5417\uff1f<\/strong>\uff08\u901a\u8fc7 LSP \u6d4b\u8bd5\uff09<\/li>\n\n\n\n<li><strong>\u5b50\u7c7b\u771f\u7684\u9700\u8981\u7236\u7c7b\u7684\u5b9e\u73b0\u5417\uff1f<\/strong>\uff08\u590d\u7528 vs \u884c\u4e3a\u7684\u5dee\u5f02\u5316\uff09<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ee7\u627f\u7684\u9002\u7528\u573a\u666f\u4e3e\u4f8b\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u6846\u67b6\u6269\u5c55<\/strong>\uff1aSpring \u4e2d\u5f88\u591a\u7c7b\u7ee7\u627f\u6846\u67b6\u57fa\u7c7b\uff0c\u8986\u76d6\u7279\u5b9a\u65b9\u6cd5\u5b9e\u73b0\u5b9a\u5236\u903b\u8f91<\/li>\n\n\n\n<li><strong>\u6a21\u677f\u65b9\u6cd5\u6a21\u5f0f<\/strong>\uff1a\u7236\u7c7b\u5b9a\u597d\u9aa8\u67b6\uff0c\u5b50\u7c7b\u586b\u5145\u7ec6\u8282\uff08\u6211\u4eec\u4e0a\u4e00\u7bc7\u7684\u85aa\u8d44\u8ba1\u7b97\u6848\u4f8b\uff09<\/li>\n\n\n\n<li><strong>\u5c42\u7ea7\u6e05\u6670\u7684\u6570\u636e\u6a21\u578b<\/strong>\uff1a\u52a8\u7269\u2192\u54fa\u4e73\u52a8\u7269\u2192\u72d7\uff0c\u8fd9\u79cd\u5c42\u6b21\u7ed3\u6784\u5929\u7136\u7a33\u5b9a<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u4e09\u3001\u7ee7\u627f\u7684\u7f3a\u70b9<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ee7\u627f\u4e0d\u662f\u94f6\u5f39\u3002\u4e0d\u52a0\u8282\u5236\u7684\u7ee7\u627f\u4f1a\u5e26\u6765\u5f88\u591a\u95ee\u9898\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u5f3a\u8026\u5408<\/strong>\uff1a\u5b50\u7c7b\u4f9d\u8d56\u4e8e\u7236\u7c7b\u7684\u5b9e\u73b0\u7ec6\u8282\uff0c\u7236\u7c7b\u4e00\u6539\u5b50\u7c7b\u5c31\u53ef\u80fd\u574f<\/li>\n\n\n\n<li><strong>\u8106\u5f31\u6027<\/strong>\uff1a\u7236\u7c7b\u7684\u4fee\u6539\u53ef\u80fd\u610f\u5916\u5f71\u54cd\u6240\u6709\u5b50\u7c7b\u7684\u884c\u4e3a<\/li>\n\n\n\n<li><strong>\u5c42\u6b21\u81a8\u80c0<\/strong>\uff1a\u968f\u7740\u9700\u6c42\u53d8\u5316\uff0c\u7ee7\u627f\u6811\u53ef\u80fd\u8d8a\u6765\u8d8a\u6df1\uff0c\u8d8a\u6765\u8d8a\u96be\u7ef4\u62a4<\/li>\n\n\n\n<li><strong>\u4e0d\u7075\u6d3b<\/strong>\uff1a\u4e00\u4e2a\u7c7b\u53ea\u80fd\u6709\u4e00\u4e2a\u7236\u7c7b\uff08Java \u5355\u7ee7\u627f\uff09\uff0c\u9009\u62e9\u7684\u7075\u6d3b\u6027\u4e0d\u591f<\/li>\n\n\n\n<li><strong>\u7834\u574f\u5c01\u88c5<\/strong>\uff1a\u5b50\u7c7b\u53ef\u4ee5\u8bbf\u95ee\u7236\u7c7b\u7684 protected \u6210\u5458\uff0c\u7ee7\u627f\u7834\u574f\u4e86\u5c01\u88c5\u6027<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u56db\u3001\u7ec4\u5408\u4f18\u5148\uff08Composition Over Inheritance\uff09<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ec4\u5408\u7684\u610f\u601d\u662f\uff1a\u4e00\u4e2a\u7c7b<strong>\u5305\u542b<\/strong>\u53e6\u4e00\u4e2a\u7c7b\u7684\u5b9e\u4f8b\uff0c\u901a\u8fc7\u59d4\u6258\u6765\u5b9e\u73b0\u300c\u590d\u7528\u300d\uff0c\u800c\u4e0d\u662f\u901a\u8fc7\u7ee7\u627f\u6765\u300c\u662f\u300d\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e3e\u4e2a\u4f8b\u5b50\uff1a\u5047\u8bbe\u6211\u4eec\u9700\u8981\u4e00\u4e2a\u300c\u4f1a\u98de\u7684\u9e2d\u5b50\u300d\u3002\u7528\u7ee7\u627f\u7684\u65b9\u5f0f\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\/\/ \u274c \u7528\u7ee7\u627f\u2014\u2014\u5c42\u7ea7\u5f88\u5bb9\u6613\u81a8\u80c0\nclass Duck {\n    public void quack() { System.out.println(\"\u560e\u560e\"); }\n}\n\nclass FlyingDuck extends Duck {\n    public void fly() { System.out.println(\"\u98de\u8d77\u6765\u4e86\uff01\"); }\n}\n\nclass SwimmingDuck extends Duck {\n    public void swim() { System.out.println(\"\u6e38\u6c34\u4e2d\"); }\n}\n\n\/\/ \u9700\u8981\u65e2\u80fd\u98de\u53c8\u80fd\u6e38\u7684\u9e2d\u5b50\u600e\u4e48\u529e\uff1f\n\/\/ \u8981\u4e48\u591a\u91cd\u7ee7\u627f\uff08Java \u4e0d\u652f\u6301\uff09\uff0c\u8981\u4e48\u518d\u52a0\u4e00\u5c42... \u5f88\u5feb\u5c42\u7ea7\u5c31\u4e71\u5957\u4e86<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u7528\u7ec4\u5408\u7684\u65b9\u5f0f\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\/\/ \u2705 \u7528\u7ec4\u5408\u2014\u2014\u7075\u6d3b\u3001\u53ef\u63d2\u62d4\ninterface FlyBehavior {\n    void fly();\n}\n\ninterface SwimBehavior {\n    void swim();\n}\n\nclass FlyWithWings implements FlyBehavior {\n    @Override\n    public void fly() { System.out.println(\"\u7528\u7fc5\u8180\u98de\"); }\n}\n\nclass NoFly implements FlyBehavior {\n    @Override\n    public void fly() { \/* \u4ec0\u4e48\u4e5f\u4e0d\u505a *\/ }\n}\n\nclass SwimNormally implements SwimBehavior {\n    @Override\n    public void swim() { System.out.println(\"\u6b63\u5e38\u6e38\u6cf3\"); }\n}\n\nclass Duck {\n    private FlyBehavior flyBehavior;\n    private SwimBehavior swimBehavior;\n\n    public Duck(FlyBehavior fly, SwimBehavior swim) {\n        this.flyBehavior = fly;\n        this.swimBehavior = swim;\n    }\n\n    public void performFly() { flyBehavior.fly(); }\n    public void performSwim() { swimBehavior.swim(); }\n\n    \/\/ \u8fd0\u884c\u65f6\u8fd8\u80fd\u6539\u884c\u4e3a\uff01\n    public void setFlyBehavior(FlyBehavior fb) { this.flyBehavior = fb; }\n}\n\npublic class Main {\n    public static void main(String&#91;] args) {\n        Duck mallard = new Duck(new FlyWithWings(), new SwimNormally());\n        mallard.performFly();  \/\/ \u7528\u7fc5\u8180\u98de\n        mallard.performSwim(); \/\/ \u6b63\u5e38\u6e38\u6cf3\n\n        Duck rubber = new Duck(new NoFly(), new SwimNormally());\n        rubber.performFly();   \/\/ \u4ec0\u4e48\u4e5f\u4e0d\u505a\uff08\u4e0d\u4f1a\u98de\u7684\u6a61\u76ae\u9e2d\uff09\n    }\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u5c31\u662f<strong>\u7b56\u7565\u6a21\u5f0f\uff08Strategy Pattern\uff09<\/strong>\u7684\u4f53\u73b0\u3002\u7ec4\u5408\u628a\u300c\u884c\u4e3a\u300d\u72ec\u7acb\u6210\u63a5\u53e3\u548c\u5b9e\u73b0\u7c7b\uff0c\u901a\u8fc7\u6784\u9020\u5668\u6216 setter \u6ce8\u5165\uff0c\u6bd4\u7ee7\u627f\u7075\u6d3b\u5f97\u591a\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u677e\u8026\u5408<\/strong>\uff1aDuck \u4e0d\u4f9d\u8d56\u5177\u4f53\u884c\u4e3a\u5b9e\u73b0\uff0c\u53ea\u4f9d\u8d56\u63a5\u53e3<\/li>\n\n\n\n<li><strong>\u53ef\u590d\u7528<\/strong>\uff1a<code>FlyWithWings<\/code> \u53ef\u4ee5\u88ab\u4efb\u4f55\u9700\u8981\u98de\u884c\u80fd\u529b\u7684\u7c7b\u590d\u7528<\/li>\n\n\n\n<li><strong>\u8fd0\u884c\u65f6\u53ef\u53d8<\/strong>\uff1a\u53ef\u4ee5\u901a\u8fc7 <code>setFlyBehavior()<\/code> \u52a8\u6001\u6539\u53d8\u884c\u4e3a<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e94\u3001\u7efc\u5408\u6848\u4f8b\uff1a\u5feb\u9012\u914d\u9001\u7cfb\u7edf<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u7528\u4e00\u4e2a\u63a5\u8fd1\u771f\u5b9e\u9879\u76ee\u7684\u6848\u4f8b\uff0c\u628a\u7ee7\u627f\u3001LSP\u3001\u7ec4\u5408\u90fd\u4e32\u8d77\u6765\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>import java.util.List;\nimport java.util.ArrayList;\n\n\/\/ ========== \u884c\u4e3a\u63a5\u53e3\uff08\u7ec4\u5408\u7684\u90e8\u5206\uff09 ==========\n\ninterface ShippingStrategy {\n    double calculateCost(double weight, double distance);\n    String getMethodName();\n}\n\ninterface TrackingCapability {\n    String track(String orderId);\n}\n\n\/\/ ========== \u7b56\u7565\u5b9e\u73b0 ==========\n\nclass StandardShipping implements ShippingStrategy {\n    @Override\n    public double calculateCost(double weight, double distance) {\n        return weight * 1.5 + distance * 0.5;\n    }\n\n    @Override\n    public String getMethodName() { return \"\u6807\u51c6\u914d\u9001\"; }\n}\n\nclass ExpressShipping implements ShippingStrategy {\n    @Override\n    public double calculateCost(double weight, double distance) {\n        return weight * 3.0 + distance * 1.2 + 10; \/\/ \u989d\u5916\u52a0\u6025\u8d39\n    }\n\n    @Override\n    public String getMethodName() { return \"\u52a0\u6025\u914d\u9001\"; }\n}\n\nclass SimpleTracker implements TrackingCapability {\n    @Override\n    public String track(String orderId) {\n        return \"\u8ba2\u5355 \" + orderId + \"\uff1a\u5f53\u524d\u72b6\u6001\u2014\u2014\u8fd0\u8f93\u4e2d\";\n    }\n}\n\n\/\/ ========== \u7ee7\u627f\u5c42\u6b21\uff08\u7a33\u5b9a\u7684 is-a \u5173\u7cfb\uff09 ==========\n\nabstract class Package {\n    protected String id;\n    protected double weight;    \/\/ kg\n    protected double distance;  \/\/ km\n    protected ShippingStrategy shipping;\n\n    public Package(String id, double weight, double distance, ShippingStrategy shipping) {\n        this.id = id;\n        this.weight = weight;\n        this.distance = distance;\n        this.shipping = shipping;\n    }\n\n    public final String getId() { return id; }\n\n    \/\/ \u6a21\u677f\u65b9\u6cd5\uff1a\u5b50\u7c7b\u53ef\u91cd\u5199\u8ba1\u7b97\u7ec6\u8282\n    public double calculateTotalCost() {\n        return shipping.calculateCost(weight, distance);\n    }\n\n    public abstract String getDescription();\n\n    public String getShippingMethod() {\n        return shipping.getMethodName();\n    }\n}\n\n\/\/ \u666e\u901a\u5305\u88f9\u2014\u2014\u7a33\u5b9a\uff0c\u4e0d\u4f1a\u6709\u5947\u602a\u7684\u884c\u4e3a\nclass RegularPackage extends Package {\n    public RegularPackage(String id, double weight, double distance, ShippingStrategy shipping) {\n        super(id, weight, distance, shipping);\n    }\n\n    @Override\n    public String getDescription() {\n        return \"\u666e\u901a\u5305\u88f9 #\" + id + \"\uff08\" + weight + \"kg, \" + distance + \"km\uff09\";\n    }\n}\n\n\/\/ \u6613\u788e\u54c1\u5305\u88f9\u2014\u2014\u53ef\u4ee5\u5b89\u5168\u66ff\u6362 Package\nclass FragilePackage extends Package {\n    private static final double FRAGILE_SURCHARGE = 5.0;\n\n    public FragilePackage(String id, double weight, double distance, ShippingStrategy shipping) {\n        super(id, weight, distance, shipping);\n    }\n\n    @Override\n    public double calculateTotalCost() {\n        return super.calculateTotalCost() + FRAGILE_SURCHARGE;\n    }\n\n    @Override\n    public String getDescription() {\n        return \"\u26a0\ufe0f \u6613\u788e\u54c1 #\" + id + \"\uff08\" + weight + \"kg, \" + distance + \"km\uff09\";\n    }\n}\n\n\/\/ ========== \u914d\u9001\u7cfb\u7edf ==========\n\nclass DeliverySystem {\n    private List packages = new ArrayList();\n\n    public void addPackage(Package pkg) {\n        packages.add(pkg);\n    }\n\n    public void printAllOrders() {\n        for (Package pkg : packages) {\n            System.out.println(pkg.getDescription());\n            System.out.println(\"  \u914d\u9001\u65b9\u5f0f\uff1a\" + pkg.getShippingMethod());\n            System.out.println(\"  \u603b\u8d39\u7528\uff1a\u00a5\" + pkg.calculateTotalCost());\n\n            \/\/ \u6709\u8ffd\u8e2a\u80fd\u529b\u7684\u989d\u5916\u8f93\u51fa\n            if (pkg instanceof TrackingCapability) {\n                System.out.println(\"  \" + ((TrackingCapability) pkg).track(pkg.getId()));\n            }\n            System.out.println();\n        }\n    }\n}\n\n\/\/ ========== \u5ba2\u6237\u7aef ==========\n\npublic class Main {\n    public static void main(String&#91;] args) {\n        DeliverySystem system = new DeliverySystem();\n\n        \/\/ \u6ee1\u8db3 LSP\uff1a\u54ea\u91cc\u7528 Package\uff0c\u5c31\u80fd\u653e RegularPackage \u6216 FragilePackage\n        system.addPackage(new RegularPackage(\"A001\", 2.5, 100, new StandardShipping()));\n        system.addPackage(new RegularPackage(\"A002\", 10.0, 50, new ExpressShipping()));\n        system.addPackage(new FragilePackage(\"A003\", 1.2, 200, new StandardShipping()));\n\n        \/\/ \u4e00\u4e2a\u7279\u6b8a\u7684\u53ef\u8ffd\u8e2a\u5305\u88f9\u2014\u2014\u901a\u8fc7\u7ec4\u5408\u5b9e\u73b0\u4e86\u989d\u5916\u80fd\u529b\n        Package tracked = new RegularPackage(\"A004\", 3.0, 80, new ExpressShipping()) {\n            private TrackingCapability tracker = new SimpleTracker();\n\n            @Override\n            public String getDescription() {\n                return \"\ud83d\udce6 \u53ef\u8ffd\u8e2a\u5305\u88f9 #\" + getId();\n            }\n        };\n        system.addPackage(tracked);\n\n        system.printAllOrders();\n    }\n}<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd0\u884c\u8f93\u51fa\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\u666e\u901a\u5305\u88f9 #A001\uff082.5kg, 100km\uff09\n  \u914d\u9001\u65b9\u5f0f\uff1a\u6807\u51c6\u914d\u9001\n  \u603b\u8d39\u7528\uff1a\u00a553.75\n\n\u666e\u901a\u5305\u88f9 #A002\uff0810.0kg, 50km\uff09\n  \u914d\u9001\u65b9\u5f0f\uff1a\u52a0\u6025\u914d\u9001\n  \u603b\u8d39\u7528\uff1a\u00a5100.0\n\n\u26a0\ufe0f \u6613\u788e\u54c1 #A003\uff081.2kg, 200km\uff09\n  \u914d\u9001\u65b9\u5f0f\uff1a\u6807\u51c6\u914d\u9001\n  \u603b\u8d39\u7528\uff1a\u00a5101.8\n\n\ud83d\udce6 \u53ef\u8ffd\u8e2a\u5305\u88f9 #A004\n  \u914d\u9001\u65b9\u5f0f\uff1a\u52a0\u6025\u914d\u9001\n  \u603b\u8d39\u7528\uff1a\u00a5115.0\n  \ud83d\udc49 \u8ba2\u5355 A004\uff1a\u5f53\u524d\u72b6\u6001\u2014\u2014\u8fd0\u8f93\u4e2d<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u4e2a\u6848\u4f8b\u4e2d\u4f60\u80fd\u770b\u5230\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u7ee7\u627f\u7528\u4e8e\u7a33\u5b9a\u5c42\u6b21<\/strong>\uff1a<code>Package \u2192 RegularPackage \/ FragilePackage<\/code>\uff0c\u8fd9\u662f\u771f\u6b63\u7684 is-a \u5173\u7cfb\uff0c\u884c\u4e3a\u4e00\u81f4\uff0c\u6ee1\u8db3 LSP<\/li>\n\n\n\n<li><strong>\u7ec4\u5408\u7528\u4e8e\u53ef\u53d8\u884c\u4e3a<\/strong>\uff1a<code>ShippingStrategy<\/code> \u901a\u8fc7\u63a5\u53e3\u6ce8\u5165\uff0c\u914d\u9001\u7b56\u7565\u53ef\u4ee5\u81ea\u7531\u5207\u6362\u548c\u590d\u7528<\/li>\n\n\n\n<li><strong>\u6a21\u677f\u65b9\u6cd5<\/strong>\uff1a<code>calculateTotalCost()<\/code> \u5728\u57fa\u7c7b\u4e2d\u5b9a\u4e49\u6d41\u7a0b\uff0c\u5b50\u7c7b\u53ef\u4ee5\u6269\u5c55\uff08\u5982 FragilePackage \u52a0\u6613\u788e\u9644\u52a0\u8d39\uff09<\/li>\n\n\n\n<li><strong>final \u65b9\u6cd5<\/strong>\uff1a<code>getId()<\/code> \u88ab\u58f0\u660e\u4e3a final\uff0c\u4fdd\u8bc1\u6807\u8bc6\u7b26\u4e0d\u88ab\u7be1\u6539<\/li>\n\n\n\n<li><strong>\u7ec4\u5408\u5b9e\u73b0\u989d\u5916\u80fd\u529b<\/strong>\uff1a<code>TrackingCapability<\/code> \u4f5c\u4e3a\u63a5\u53e3\uff0c\u4efb\u4f55\u9700\u8981\u8ffd\u8e2a\u80fd\u529b\u7684\u5305\u88f9\u90fd\u53ef\u4ee5\u7ec4\u5408\u8fdb\u53bb<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">\u516d\u3001\u7ee7\u627f\u4e0e\u7ec4\u5408\u7684\u51b3\u7b56\u6307\u5357<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728\u5b9e\u9645\u5199\u4ee3\u7801\u65f6\uff0c\u53ef\u4ee5\u6309\u4e0b\u9762\u8fd9\u4e2a\u6d41\u7a0b\u505a\u51b3\u5b9a\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u9996\u5148\u95ee<\/strong>\uff1a\u4e24\u4e2a\u7c7b\u4e4b\u95f4\u771f\u7684\u662f\u300cis-a\u300d\u5173\u7cfb\u5417\uff1f\u8fd8\u662f\u300chas-a\u300d\u5173\u7cfb\uff1f\n<ul class=\"wp-block-list\">\n<li>Dog is-a Animal \u2192 \u53ef\u4ee5\u8003\u8651\u7ee7\u627f<\/li>\n\n\n\n<li>Car has-a Engine \u2192 \u7528\u7ec4\u5408<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>\u518d\u95ee<\/strong>\uff1a\u5b50\u7c7b\u662f\u5426\u80fd\u5b8c\u5168\u66ff\u4ee3\u7236\u7c7b\uff1f\u5982\u679c\u5b50\u7c7b\u4f1a\u6539\u53d8\u7236\u7c7b\u7684\u9884\u671f\u884c\u4e3a\uff0c\u5c31\u4e0d\u8981\u7ee7\u627f\u3002<\/li>\n\n\n\n<li><strong>\u518d\u95ee<\/strong>\uff1a\u5b50\u7c7b\u662f\u300c\u6269\u5c55\u300d\u7236\u7c7b\uff0c\u8fd8\u662f\u300c\u590d\u7528\u300d\u7236\u7c7b\u4ee3\u7801\uff1f\n<ul class=\"wp-block-list\">\n<li>\u5982\u679c\u662f\u6269\u5c55\u884c\u4e3a \u2192 \u7ee7\u627f\u5408\u9002<\/li>\n\n\n\n<li>\u5982\u679c\u53ea\u662f\u4e3a\u4e86\u590d\u7528\u4ee3\u7801 \u2192 \u7ec4\u5408\u66f4\u5b89\u5168<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>\u6700\u540e\u95ee<\/strong>\uff1a\u8fd9\u4e2a\u7ee7\u627f\u5c42\u6b21\u672a\u6765\u4f1a\u88ab\u522b\u4eba\u7528\u5417\uff1f\u5982\u679c\u4f1a\u88ab\u5916\u90e8\u6269\u5c55\uff0c\u786e\u4fdd\u57fa\u7c7b\u8bbe\u8ba1\u7a33\u5b9a\u3002<\/li>\n<\/ol>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>\u4f7f\u7528\u7ee7\u627f<\/th><th>\u4f7f\u7528\u7ec4\u5408<\/th><\/tr><\/thead><tbody><tr><td>\u771f\u6b63\u7684 is-a \u5173\u7cfb<\/td><td>has-a \u5173\u7cfb<\/td><\/tr><tr><td>\u5b50\u7c7b\u80fd\u5b8c\u5168\u66ff\u4ee3\u7236\u7c7b\uff08LSP\uff09<\/td><td>\u9700\u8981\u7075\u6d3b\u5207\u6362\u884c\u4e3a<\/td><\/tr><tr><td>\u6846\u67b6\u8981\u6c42\u6269\u5c55\u57fa\u7c7b<\/td><td>\u884c\u4e3a\u9700\u8981\u8fd0\u884c\u65f6\u53d8\u66f4<\/td><\/tr><tr><td>\u5c42\u6b21\u7ed3\u6784\u5929\u7136\u7a33\u5b9a\u4e0d\u53d8<\/td><td>\u9700\u8981\u907f\u514d\u5f3a\u8026\u5408<\/td><\/tr><tr><td>\u6a21\u677f\u65b9\u6cd5\u6a21\u5f0f<\/td><td>\u7b56\u7565\u6a21\u5f0f\u3001\u88c5\u9970\u5668\u6a21\u5f0f<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">\u7ed3\u8bed\u2014\u2014\u7ee7\u627f\u4e13\u9898\u56de\u987e<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u6574\u4e2a\u7ee7\u627f\u4e13\u9898\u7ed3\u675f\u4e86\uff0c\u6211\u4eec\u4e00\u8d77\u6765\u56de\u987e\u4e00\u4e0b\u8fd9\u56db\u7bc7\u8d70\u8fc7\u7684\u8def\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u7b2c 1 \u7bc7<\/strong>\uff1a\u7ee7\u627f\u57fa\u7840\u2014\u2014extends \u8bed\u6cd5\u3001\u7236\u5b50\u7c7b\u5173\u7cfb\u3001\u7ee7\u627f vs \u7ec4\u5408\u7684\u521d\u6b65\u4e86\u89e3<\/li>\n\n\n\n<li><strong>\u7b2c 2 \u7bc7<\/strong>\uff1asuper \u5173\u952e\u5b57\u4e0e\u6784\u9020\u5668\u94fe\u2014\u2014\u6784\u9020\u5668\u7684\u6267\u884c\u987a\u5e8f\u3001\u591a\u5c42\u7ee7\u627f\u3001protected<\/li>\n\n\n\n<li><strong>\u7b2c 3 \u7bc7<\/strong>\uff1a\u65b9\u6cd5\u91cd\u5199\u4e0e final\u2014\u2014Override \u89c4\u5219\u3001\u52a8\u6001\u7ed1\u5b9a\u3001final \u7c7b\/\u65b9\u6cd5\/\u53d8\u91cf<\/li>\n\n\n\n<li><strong>\u7b2c 4 \u7bc7<\/strong>\uff1a\u7ee7\u627f\u4f53\u7cfb\u8bbe\u8ba1\u5b9e\u6218\u2014\u2014LSP \u539f\u5219\u3001\u7ec4\u5408\u4f18\u5148\u3001\u7efc\u5408\u6848\u4f8b<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u7ee7\u627f\u662f\u7406\u89e3\u9762\u5411\u5bf9\u8c61\u7684\u5173\u952e\u67a2\u7ebd\u3002\u5b83\u8fde\u63a5\u4e86\u5c01\u88c5\uff08\u901a\u8fc7 protected \u63a7\u5236\u53ef\u89c1\u6027\uff09\u3001\u94fa\u57ab\u4e86\u591a\u6001\uff08\u901a\u8fc7\u91cd\u5199\u5b9e\u73b0\u52a8\u6001\u7ed1\u5b9a\uff09\u3002\u638c\u63e1\u4e86\u7ee7\u627f\uff0c\u4f60\u5c31\u62e5\u6709\u4e86\u6784\u5efa\u7c7b\u5c42\u6b21\u7ed3\u6784\u7684\u80fd\u529b\u2014\u2014\u4f46\u4f60\u4e5f\u6709\u4e86\u300c\u6ee5\u7528\u7ee7\u627f\u300d\u7684\u98ce\u9669\u3002<\/p>\n\n\n\n<p 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