{"id":641,"date":"2015-05-08T15:39:01","date_gmt":"2015-05-08T07:39:01","guid":{"rendered":"https:\/\/ai.zhousir.top\/?p=641"},"modified":"2026-08-18T12:09:33","modified_gmt":"2026-08-18T04:09:33","slug":"%e8%ae%be%e8%ae%a1%e6%a8%a1%e5%bc%8f%e4%b9%8bfactory","status":"publish","type":"post","link":"https:\/\/ai.zhousir.top\/?p=641","title":{"rendered":"\u8bbe\u8ba1\u6a21\u5f0f\u4e4bFactory"},"content":{"rendered":"
\n

\u5de5\u5382\u6a21\u5f0f\u5982\u6b64\u5e38\u7528\uff0c\u662f\u56e0\u4e3a\u5b83\u76f8\u5f53\u4e8e\u521b\u5efa\u5b9e\u4f8b\u5bf9\u8c61\u7684 new<\/code>\u3002\u6211\u4eec\u7ecf\u5e38\u8981\u6839\u636e\u7c7b\u751f\u6210\u5b9e\u4f8b\uff0c\u5982 A a = new A()<\/code>\u3002\u4ee5\u540e\u518d\u5199 new<\/code> \u65f6\u4e0d\u59a8\u591a\u60f3\u4e00\u6b65\uff1a\u80fd\u4e0d\u80fd\u6539\u7528\u5de5\u5382\uff1f\u867d\u7136\u53ef\u80fd\u591a\u5199\u4e00\u70b9\u4ee3\u7801\uff0c\u4f46\u80fd\u6362\u6765\u66f4\u5927\u7684\u53ef\u6269\u5c55\u6027\u548c\u5c3d\u91cf\u5c11\u7684\u4fee\u6539\u91cf\u3002<\/p>\n

<\/p>\n

\u4ee5\u7c7b Sample<\/code> \u4e3a\u4f8b\uff0c\u521b\u5efa\u5b9e\u4f8b\u672c\u6765\u662f Sample sample = new Sample();<\/code>\u3002\u5b9e\u9645\u4e2d\u521b\u5efa\u65f6\u5f80\u5f80\u8fd8\u8981\u505a\u521d\u59cb\u5316\uff1a\u8d4b\u503c\u3001\u67e5\u5e93\u7b49\u3002\u53c2\u6570\u7b80\u5355\u65f6\u53ef\u4ee5\u5199\u6210 new Sample(\u53c2\u6570)<\/code>\uff1b\u521d\u59cb\u5316\u82e5\u662f\u5f88\u957f\u4e00\u6bb5\u4ee3\u7801\uff0c\u585e\u8fdb\u6784\u9020\u51fd\u6570\u4f1a\u5f88\u96be\u770b\uff0c\u4e5f\u8fdd\u80cc\u5c01\u88c5\u548c\u5206\u6d3e\uff1a\u957f\u4ee3\u7801\u5e94\u5207\u5272\u3001\u5c01\u88c5\uff0c\u964d\u4f4e\u6bb5\u4e0e\u6bb5\u4e4b\u95f4\u7684\u8026\u5408\u3002<\/p>\n

\u4e00\u3001\u4e3a\u4ec0\u4e48\u8981\u628a new \u6362\u6210\u5de5\u5382<\/h2>\n

\u521b\u5efa\u5b9e\u4f8b\u548c\u4f7f\u7528\u5b9e\u4f8b\u8981\u5206\u5f00\uff1a\u5927\u91cf\u521d\u59cb\u5316\u5de5\u4f5c\u5e94\u4ece Sample<\/code> \u7684\u6784\u9020\u51fd\u6570\u91cc\u62c6\u51fa\u53bb\uff0c\u8fd9\u65f6\u5c31\u4e0d\u80fd\u518d\u7528\u7b80\u5355\u7684 new Sample(\u53c2\u6570)<\/code>\u3002\u82e5 Sample<\/code> \u6709\u5b50\u7c7b MySample<\/code>\uff0c\u6309\u9762\u5411\u63a5\u53e3\u7f16\u7a0b\u5e94\u628a Sample<\/code> \u62bd\u8c61\u6210\u63a5\u53e3\uff0c\u4e0b\u9762\u6709 MySample<\/code> \u548c HisSample<\/code>\uff1a<\/p>\n

Sample mysample = new MySample();\nSample hissample = new HisSample();<\/code><\/pre>\n
\u9879\u76ee\u6df1\u5165\u540e Sample<\/code> \u8fd8\u53ef\u80fd\u201c\u751f\u51fa\u5f88\u591a\u513f\u5b50\u201d\uff0c\u4f20\u7edf\u5199\u6cd5\u8981\u5bf9\u6bcf\u4e2a\u513f\u5b50 new<\/code> \u4e00\u6b21\uff0c\u751a\u81f3\u6539\u4ee5\u524d\u7684\u4ee3\u7801\u3002\u4e00\u5f00\u59cb\u5c31\u7528\u5de5\u5382\uff0c\u8fd9\u4e9b\u9ebb\u70e6\u5c31\u6ca1\u6709\u4e86\u3002<\/p>\n
\u4e8c\u3001\u5de5\u5382\u65b9\u6cd5<\/h2>\n
\u4e13\u95e8\u5efa\u4e00\u4e2a\u751f\u4ea7 Sample<\/code> \u5b9e\u4f8b\u7684\u5de5\u5382\uff1a<\/p>\n
public class Factory {\n    public static Sample creator(int which) {\n        \/\/ getClass \u4ea7\u751f Sample\uff0c\u4e00\u822c\u53ef\u4f7f\u7528\u52a8\u6001\u7c7b\u88c5\u8f7d\u88c5\u5165\u7c7b\n        if (which == 1)\n            return new SampleA();\n        else if (which == 2)\n            return new SampleB();\n        return null;\n    }\n}<\/code><\/pre>\n
\u7a0b\u5e8f\u91cc\u8981\u5b9e\u4f8b\u5316 Sample<\/code> \u65f6\u5199\u6210\uff1a<\/p>\n
Sample sampleA = Factory.creator(1);<\/code><\/pre>\n
\u6574\u6bb5\u4ee3\u7801\u4e0d\u518d\u6d89\u53ca Sample<\/code> \u7684\u5177\u4f53\u5b50\u7c7b\uff0c\u8fbe\u5230\u5c01\u88c5\u6548\u679c\uff0c\u4e5f\u51cf\u5c11\u6539\u9519\u673a\u4f1a\u3002\u901a\u4fd7\u8bf4\u6cd5\uff1a\u5177\u4f53\u4e8b\u60c5\u505a\u5f97\u8d8a\u591a\u8d8a\u5bb9\u6613\u72af\u9519\uff1b\u5de5\u5382\u628a\u201c\u600e\u4e48 new\u201d\u85cf\u8d77\u6765\uff0c\u8c03\u7528\u65b9\u53ea\u8ba4\u63a5\u53e3\u3002<\/p>\n
\u4f7f\u7528\u5de5\u5382\u65b9\u6cd5\u8981\u6ce8\u610f\u51e0\u4e2a\u89d2\u8272\uff1a\u5148\u5b9a\u4e49\u4ea7\u54c1\u63a5\u53e3\uff08\u5982 Sample<\/code>\uff09\uff0c\u4e0b\u9762\u6709\u5b9e\u73b0\u7c7b\uff08\u5982 SampleA<\/code>\uff09\uff0c\u518d\u6709\u4e00\u4e2a factory<\/code> \u7c7b\u7528\u6765\u751f\u6210\u4ea7\u54c1\u3002\u4e0b\u56fe\u6700\u53f3\u8fb9\u662f\u751f\u4ea7\u51fa\u7684\u5bf9\u8c61 Sample<\/code>\uff1a<\/p>\n
\"factory\"<\/p>\n
\u4e09\u3001\u53cd\u5c04\u5b9e\u73b0\u5de5\u5382\u65b9\u6cd5<\/h2>\n
\u7528 Class.forName(className).newInstance()<\/code> \u6309\u7c7b\u540d\u52a8\u6001\u88c5\u5165\u4ea7\u54c1\uff0c\u6362\u5b9e\u73b0\u7c7b\u65f6\u4e0d\u5fc5\u6539\u5de5\u5382\u5185\u90e8\u7684 if\/else<\/code>\u3002\u539f\u6587\u91cc\u63a5\u53e3\u65b9\u6cd5\u3001\u8d4b\u503c\u8bed\u53e5\u6f0f\u4e86\u5206\u53f7\uff0c\u4e0b\u9762\u6309\u53ef\u7f16\u8bd1\u5199\u6cd5\u8865\u5168\uff1a<\/p>\n
package com.scxh.java.factory;\ninterface Fruit { \/\/ \u6c34\u679c\u63a5\u53e3\n    public void eat(); \/\/ \u5403\u6c34\u679c\n}\nclass Apple implements Fruit { \/\/ \u5b9a\u4e49\u82f9\u679c\n    public void eat() {\n        System.out.println(\"**\u5403\u82f9\u679c\u3002\");\n    }\n}\nclass Orange implements Fruit {\n    public void eat() {\n        System.out.println(\"**\u5403\u6a58\u5b50\u3002\");\n    }\n}\nclass Factory {\n    public static Fruit getInstance(String className) {\n        Fruit fruit = null;\n        try {\n            fruit = (Fruit) Class.forName(className).newInstance();\n        } catch (Exception e) {\n            e.printStackTrace();\n        }\n        return fruit;\n    }\n}\npublic class FactoryDemo {\n    public static void main(String args[]) { \/\/ \u901a\u8fc7\u5de5\u5382\u53d6\u5f97\u63a5\u53e3\u5b9e\u4f8b\uff0c\u4f20\u5165\u5b8c\u6574\u7684\u5305.\u7c7b\u540d\u79f0\n        Fruit f = Factory.getInstance(\"com.scxh.java.factorydemo.Apple\");\n        if (f != null) { \/\/ \u5224\u65ad\u662f\u5426\u53d6\u5f97\u63a5\u53e3\u5b9e\u4f8b\n            f.eat();\n        }\n    }\n}<\/code><\/pre>\n
\u56db\u3001\u62bd\u8c61\u5de5\u5382<\/h2>\n
\u5de5\u5382\u6a21\u5f0f\u91cc\u6709\u5de5\u5382\u65b9\u6cd5\uff08Factory Method\uff09\u548c\u62bd\u8c61\u5de5\u5382\uff08Abstract Factory\uff09\u3002\u5dee\u522b\u5728\u4e8e\u521b\u5efa\u5bf9\u8c61\u7684\u590d\u6742\u7a0b\u5ea6\u3002\u5de5\u5382\u65b9\u6cd5\u53ea\u521b\u5efa\u4e00\u79cd\u4ea7\u54c1 Sample<\/code>\uff1b\u82e5\u8fd8\u6709\u65b0\u4ea7\u54c1\u63a5\u53e3 Sample2<\/code>\uff0c\u4e14 Sample<\/code> \u6709 SampleA<\/code> \/ SampleB<\/code>\uff0cSample2<\/code> \u6709 Sample2A<\/code> \/ Sample2B<\/code>\uff0c\u5c31\u628a Factory<\/code> \u505a\u6210\u62bd\u8c61\u7c7b\uff0c\u5171\u540c\u90e8\u5206\u653e\u62bd\u8c61\u7c7b\uff0c\u4e0d\u540c\u90e8\u5206\u4ea4\u7ed9\u5b50\u7c7b\uff1a<\/p>\n
public abstract class Factory {\n    public abstract Sample creator();\n    public abstract Sample2 creator(String name);\n}\n\npublic class SimpleFactory extends Factory {\n    public Sample creator() {\n        \/\/ ...\n        return new SampleA();\n    }\n    public Sample2 creator(String name) {\n        \/\/ ...\n        return new Sample2A();\n    }\n}\n\npublic class BombFactory extends Factory {\n    public Sample creator() {\n        \/\/ ...\n        return new SampleB();\n    }\n    public Sample2 creator(String name) {\n        \/\/ ...\n        return new Sample2B();\n    }\n}<\/code><\/pre>\n
\u4e24\u4e2a\u5de5\u5382\u5404\u81ea\u751f\u4ea7\u4e00\u5957 Sample<\/code> \u548c Sample2<\/code>\u3002\u4e3a\u4ec0\u4e48\u4e0d\u62c6\u6210\u4e24\u4e2a\u5de5\u5382\u65b9\u6cd5\u5206\u522b\u751f\u4ea7\uff1f\u5173\u952e\u662f SimpleFactory<\/code> \u91cc\u751f\u4ea7\u4e24\u79cd\u4ea7\u54c1\u7684\u65b9\u6cd5\u6709\u8054\u7cfb\uff0c\u8981\u6346\u5728\u4e00\u4e2a\u7c7b\u91cc\u2014\u2014\u6bd4\u5982\u5236\u9020\u5de5\u827a\u90fd\u6bd4\u8f83\u7b80\u5355\uff0c\u6240\u4ee5\u53eb SimpleFactory\u3002\u5b9e\u9645\u5e94\u7528\u4e2d\u5de5\u5382\u65b9\u6cd5\u66f4\u591a\uff0c\u800c\u4e14\u5e38\u548c\u52a8\u6001\u7c7b\u88c5\u5165\u5668\u4e00\u8d77\u7528\u3002<\/p>\n\n\n\n\n\n\n\n
\u6a21\u5f0f<\/th>\n\u4ea7\u54c1\u65cf<\/th>\n\u5178\u578b\u7528\u6cd5<\/th>\n<\/tr>\n<\/thead>\n
\u5de5\u5382\u65b9\u6cd5<\/td>\n\u4e00\u79cd\u4ea7\u54c1\u63a5\u53e3\uff0c\u591a\u4e2a\u5b9e\u73b0<\/td>\ncreator(which) \u6216 Class.forName \u88c5\u5165<\/td>\n<\/tr>\n
\u62bd\u8c61\u5de5\u5382<\/td>\n\u591a\u7ec4\u76f8\u5173\u4ea7\u54c1\u4e00\u8d77\u521b\u5efa<\/td>\n\u540c\u4e00\u5de5\u5382\u4ea7\u51fa\u914d\u5957\u7684 Sample + Sample2<\/td>\n<\/tr>\n
\u7b80\u5355\u5de5\u5382<\/td>\n\u9759\u6001\u65b9\u6cd5\u96c6\u4e2d new<\/td>\n\u6539\u4ea7\u54c1\u65f6\u4e3b\u8981\u6539\u5de5\u5382\u7c7b<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\u4e94\u3001Jive \u7684 ForumFactory<\/h2>\n
\u524d\u9762 Singleton \u91cc\u8ba8\u8bba\u8fc7\u8fd9\u4e2a\u4f8b\u5b50\uff0c\u8fd9\u91cc\u770b\u5de5\u5382\u90e8\u5206\u3002\u73b0\u5728\u7684 Jive \u7528\u6570\u636e\u5e93\u5b58\u653e\u5e16\u5b50\uff1b\u82e5\u6539\u6210\u6587\u4ef6\u7cfb\u7edf\uff0c\u53ea\u8981\u6362 className<\/code>\uff1a<\/p>\n
private static String className = \"com.jivesoftware.forum.database.DbForumFactory\";<\/code><\/pre>\n
\u7528\u81ea\u5df1\u5f00\u53d1\u7684\u521b\u5efa forum \u7684\u65b9\u6cd5\u4ee3\u66ff DbForumFactory<\/code> \u5373\u53ef\u3002<\/p>\n
public abstract class ForumFactory {\n    private static Object initLock = new Object();\n    private static String className = \"com.jivesoftware.forum.database.DbForumFactory\";\n    private static ForumFactory factory = null;\n\n    public static ForumFactory getInstance(Authorization authorization) {\n        if (authorization == null) {\n            return null;\n        }\n        \/\/ \u4ee5\u4e0b\u4f7f\u7528\u4e86 Singleton \u5355\u6001\u6a21\u5f0f\n        if (factory == null) {\n            synchronized (initLock) {\n                if (factory == null) {\n                    try {\n                        \/\/ \u52a8\u6001\u88c5\u8f7d\u7c7b\n                        Class c = Class.forName(className);\n                        factory = (ForumFactory) c.newInstance();\n                    } catch (Exception e) {\n                        return null;\n                    }\n                }\n            }\n        }\n        \/\/ \u8fd4\u56de proxy\uff0c\u7528\u6765\u9650\u5236\u6388\u6743\u5bf9 forum \u7684\u8bbf\u95ee\n        return new ForumFactoryProxy(authorization, factory,\n                factory.getPermissions(authorization));\n    }\n\n    \/\/ \u771f\u6b63\u521b\u5efa forum \u7684\u65b9\u6cd5\u7531\u7ee7\u627f ForumFactory \u7684\u5b50\u7c7b\u53bb\u5b8c\u6210\n    public abstract Forum createForum(String name, String description)\n            throws UnauthorizedException, ForumAlreadyExistsException;\n}<\/code><\/pre>\n
\u8fd9\u6bb5\u4ee3\u7801\u4e00\u5171\u7528\u4e86\u4e09\u79cd\u6a21\u5f0f\uff1a\u5de5\u5382\u3001Singleton\uff0c\u4ee5\u53ca Proxy\u3002Proxy \u7528\u6765\u6388\u6743\u8bbf\u95ee forum\uff1a\u6ce8\u518c\u7528\u6237\u548c\u6e38\u5ba2\u6743\u9650\u4e0d\u540c\uff0c\u800c\u4e14\u6743\u9650\u8d2f\u7a7f\u6574\u4e2a\u7cfb\u7edf\uff0c\u7528 proxy \u7c7b\u4f3c\u7f51\u5173\u3002<\/p>\n
\u516d\u3001Java \u5ba0\u7269\u5e97\u7684 CatalogDAOFactory<\/h2>\n
public class CatalogDAOFactory {\n    \/**\n     * \u672c\u65b9\u6cd5\u6307\u5b9a\u4e00\u4e2a\u7279\u522b\u7684\u5b50\u7c7b\u6765\u5b9e\u73b0 DAO \u6a21\u5f0f\u3002\n     * \u5177\u4f53\u5b50\u7c7b\u5b9a\u4e49\u662f\u5728 J2EE \u7684\u90e8\u7f72\u63cf\u8ff0\u5668\u4e2d\u3002\n     *\/\n    public static CatalogDAO getDAO() throws CatalogDAOSysException {\n        CatalogDAO catDao = null;\n        try {\n            InitialContext ic = new InitialContext();\n            \/\/ \u52a8\u6001\u88c5\u5165 CATALOG_DAO_CLASS\n            \/\/ \u53ef\u4ee5\u5b9a\u4e49\u81ea\u5df1\u7684 CATALOG_DAO_CLASS\uff0c\u4ece\u800c\u5728\u65e0\u9700\u53d8\u66f4\u592a\u591a\u4ee3\u7801\n            \/\/ \u7684\u524d\u63d0\u4e0b\uff0c\u5b8c\u6210\u7cfb\u7edf\u7684\u5de8\u5927\u53d8\u66f4\u3002\n            String className = (String) ic.lookup(JNDINames.CATALOG_DAO_CLASS);\n            catDao = (CatalogDAO) Class.forName(className).newInstance();\n        } catch (NamingException ne) {\n            throw new CatalogDAOSysException(\n                \"CatalogDAOFactory.getDAO: NamingException while getting DAO type : \\n\"\n                + ne.getMessage());\n        } catch (Exception se) {\n            throw new CatalogDAOSysException(\n                \"CatalogDAOFactory.getDAO: Exception while getting DAO type : \\n\"\n                + se.getMessage());\n        }\n        return catDao;\n    }\n}<\/code><\/pre>\n
CatalogDAOFactory<\/code> \u662f\u5178\u578b\u5de5\u5382\u65b9\u6cd5\u3002catDao<\/code> \u901a\u8fc7\u52a8\u6001\u7c7b\u88c5\u5165\u5668\u62ff\u5230\u5177\u4f53\u5b9e\u73b0\u5b50\u7c7b\uff0cJava \u5ba0\u7269\u5e97\u91cc\u7528\u6765\u64cd\u4f5c catalog \u6570\u636e\u5e93\u3002\u7528\u6237\u53ef\u6309\u6570\u636e\u5e93\u7c7b\u578b\u5b9a\u5236\u5b50\u7c7b\uff0c\u628a\u7c7b\u540d\u4ea4\u7ed9 CATALOG_DAO_CLASS<\/code> \u5373\u53ef\u3002<\/p>\n
\u7531\u6b64\u53ef\u89c1\uff0c\u5de5\u5382\u65b9\u6cd5\u4e3a\u7cfb\u7edf\u63d0\u4f9b\u4e86\u7075\u6d3b\u7684\u52a8\u6001\u6269\u5c55\uff1a\u53ea\u8981\u66f4\u6362\u5177\u4f53\u5de5\u5382\u65b9\u6cd5\uff0c\u7cfb\u7edf\u5176\u4ed6\u5730\u65b9\u65e0\u9700\u6539\u52a8\uff0c\u529f\u80fd\u5c31\u53ef\u4ee5\u6539\u5934\u6362\u9762\u3002<\/p>\n
\n
\u4e00\u53e5\u8bdd\u603b\u7ed3\uff1a\u5de5\u5382\u628a new \u548c\u521d\u59cb\u5316\u4ece\u8c03\u7528\u65b9\u62c6\u8d70\uff1a\u4e00\u79cd\u4ea7\u54c1\u7528\u5de5\u5382\u65b9\u6cd5\uff08\u5e38\u914d\u53cd\u5c04\uff09\uff0c\u4e00\u7ec4\u76f8\u5173\u4ea7\u54c1\u7528\u62bd\u8c61\u5de5\u5382\uff1b\u6362\u5b9e\u73b0\u53ea\u6539\u5de5\u5382\u6216\u914d\u7f6e\uff0c\u4e0d\u6539\u4e1a\u52a1\u4ee3\u7801\u3002<\/strong><\/p>\n<\/blockquote>\n<\/section>\n","protected":false},"excerpt":{"rendered":"
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