{"id":10007006,"date":"2022-12-23T10:22:45","date_gmt":"2022-12-23T02:22:45","guid":{"rendered":"https:\/\/ityet.com\/?p=10007006"},"modified":"2022-12-23T10:22:45","modified_gmt":"2022-12-23T02:22:45","slug":"dubbo%e6%9e%b6%e6%9e%84%e8%ae%be%e8%ae%a1%e4%b8%8e%e6%ba%90%e7%a0%81%e8%a7%a3%e6%9e%90%ef%bc%88%e4%b8%89%ef%bc%89%e8%b4%a3%e4%bb%bb%e9%93%be%e6%a8%a1%e5%bc%8f","status":"publish","type":"post","link":"https:\/\/itmax.cn\/?p=10007006","title":{"rendered":"Dubbo\u67b6\u6784\u8bbe\u8ba1\u4e0e\u6e90\u7801\u89e3\u6790\uff08\u4e09\uff09\u8d23\u4efb\u94fe\u6a21\u5f0f"},"content":{"rendered":"<h5><strong>\u4f5c\u8005\uff1a\u5468\u53ef\u5f3a<\/strong><\/h5>\n<h2>\u4e00\u3001\u8d23\u4efb\u94fe\u6a21\u5f0f\u7b80\u4ecb<\/h2>\n<h3>1\u3001\u8d23\u4efb\u94fe\u6a21\u5f0f\u5b9a\u4e49<\/h3>\n<p>\u8d23\u4efb\u94fe\uff08Chain of Responsibility\uff09\u6a21\u5f0f\u7684\u5b9a\u4e49\uff1a\u4e3a\u4e86\u907f\u514d\u8bf7\u6c42\u53d1\u9001\u8005\u4e0e\u591a\u4e2a\u8bf7\u6c42\u5904\u7406\u8005\u8026\u5408\u5728\u4e00\u8d77\uff0c\u4e8e\u662f\u5c06\u6240\u6709\u8bf7\u6c42\u7684\u5904\u7406\u8005\u901a\u8fc7\u524d\u4e00\u5bf9\u8c61\u8bb0\u4f4f\u5176\u4e0b\u4e00\u4e2a\u5bf9\u8c61\u7684\u5f15\u7528\u800c\u8fde\u6210\u4e00\u6761\u94fe\uff1b\u5f53\u6709\u8bf7\u6c42\u53d1\u751f\u65f6\uff0c\u53ef\u5c06\u8bf7\u6c42\u6cbf\u7740\u8fd9\u6761\u94fe\u4f20\u9012\uff0c\u76f4\u5230\u6709\u5bf9\u8c61\u5904\u7406\u5b83\u4e3a\u6b62\u3002\u5728\u8d23\u4efb\u94fe\u6a21\u5f0f\u4e2d\uff0c\u5ba2\u6237\u53ea\u9700\u8981\u5c06\u8bf7\u6c42\u53d1\u9001\u5230\u8d23\u4efb\u94fe\u4e0a\u5373\u53ef\uff0c\u65e0\u987b\u5173\u5fc3\u8bf7\u6c42\u7684\u5904\u7406\u7ec6\u8282\u548c\u8bf7\u6c42\u7684\u4f20\u9012\u8fc7\u7a0b\uff0c\u8bf7\u6c42\u4f1a\u81ea\u52a8\u8fdb\u884c\u4f20\u9012\u3002\u6240\u4ee5\u8d23\u4efb\u94fe\u5c06\u8bf7\u6c42\u7684\u53d1\u9001\u8005\u548c\u8bf7\u6c42\u7684\u5904\u7406\u8005\u89e3\u8026\u4e86\u3002<\/p>\n<h3>2\u3001\u8d23\u4efb\u94fe\u7279\u70b9<\/h3>\n<p>\u8d23\u4efb\u94fe\u6a21\u5f0f\u662f\u4e00\u79cd\u5bf9\u8c61\u884c\u4e3a\u578b\u6a21\u5f0f\uff0c<\/p>\n<p>\u5176\u4e3b\u8981\u4f18\u70b9\u5982\u4e0b\u3002<\/p>\n<p>1\uff09.\u964d\u4f4e\u4e86\u5bf9\u8c61\u4e4b\u95f4\u7684\u8026\u5408\u5ea6\u3002\u8be5\u6a21\u5f0f\u4f7f\u5f97\u4e00\u4e2a\u5bf9\u8c61\u65e0\u987b\u77e5\u9053\u5230\u5e95\u662f\u54ea\u4e00\u4e2a\u5bf9\u8c61\u5904\u7406\u5176\u8bf7\u6c42\u4ee5\u53ca\u94fe\u7684\u7ed3\u6784\uff0c\u53d1\u9001\u8005\u548c\u63a5\u6536\u8005\u4e5f\u65e0\u987b\u62e5\u6709\u5bf9\u65b9\u7684\u660e\u786e\u4fe1\u606f\u3002<\/p>\n<p>2\uff09.\u589e\u5f3a\u4e86\u7cfb\u7edf\u7684\u53ef\u6269\u5c55\u6027\u3002\u53ef\u4ee5\u6839\u636e\u9700\u8981\u589e\u52a0\u65b0\u7684\u8bf7\u6c42\u5904\u7406\u7c7b\uff0c\u6ee1\u8db3\u5f00\u95ed\u539f\u5219\u3002<\/p>\n<p>3\uff09.\u589e\u5f3a\u4e86\u7ed9\u5bf9\u8c61\u6307\u6d3e\u804c\u8d23\u7684\u7075\u6d3b\u6027\u3002\u5f53\u5de5\u4f5c\u6d41\u7a0b\u53d1\u751f\u53d8\u5316\uff0c\u53ef\u4ee5\u52a8\u6001\u5730\u6539\u53d8\u94fe\u5185\u7684\u6210\u5458\u6216\u8005\u8c03\u52a8\u5b83\u4eec\u7684\u6b21\u5e8f\uff0c\u4e5f\u53ef\u52a8\u6001\u5730\u65b0\u589e\u6216\u8005\u5220\u9664\u8d23\u4efb\u3002\u8d23\u4efb\u94fe\u7b80\u5316\u4e86\u5bf9\u8c61\u4e4b\u95f4\u7684\u8fde\u63a5\u3002\u6bcf\u4e2a\u5bf9\u8c61\u53ea\u9700\u4fdd\u6301\u4e00\u4e2a\u6307\u5411\u5176\u540e\u7ee7\u8005\u7684\u5f15\u7528\uff0c\u4e0d\u9700\u4fdd\u6301\u5176\u4ed6\u6240\u6709\u5904\u7406\u8005\u7684\u5f15\u7528\uff0c\u8fd9\u907f\u514d\u4e86\u4f7f\u7528\u4f17\u591a\u7684 if \u6216\u8005 if\u00b7\u00b7\u00b7else \u8bed\u53e5\u3002<\/p>\n<p>4\uff09.\u8d23\u4efb\u5206\u62c5\u3002\u6bcf\u4e2a\u7c7b\u53ea\u9700\u8981\u5904\u7406\u81ea\u5df1\u8be5\u5904\u7406\u7684\u5de5\u4f5c\uff0c\u4e0d\u8be5\u5904\u7406\u7684\u4f20\u9012\u7ed9\u4e0b\u4e00\u4e2a\u5bf9\u8c61\u5b8c\u6210\uff0c\u660e\u786e\u5404\u7c7b\u7684\u8d23\u4efb\u8303\u56f4\uff0c\u7b26\u5408\u7c7b\u7684\u5355\u4e00\u804c\u8d23\u539f\u5219\u3002<\/p>\n<\/p>\n<p><strong>\u5176\u4e3b\u8981\u7f3a\u70b9\u5982\u4e0b\u3002<\/strong><\/p>\n<p>1\uff09.\u4e0d\u80fd\u4fdd\u8bc1\u6bcf\u4e2a\u8bf7\u6c42\u4e00\u5b9a\u88ab\u5904\u7406\u3002\u7531\u4e8e\u4e00\u4e2a\u8bf7\u6c42\u6ca1\u6709\u660e\u786e\u7684\u63a5\u6536\u8005\uff0c\u6240\u4ee5\u4e0d\u80fd\u4fdd\u8bc1\u5b83\u4e00\u5b9a\u4f1a\u88ab\u5904\u7406\uff0c\u8be5\u8bf7\u6c42\u53ef\u80fd\u4e00\u76f4\u4f20\u5230\u94fe\u7684\u672b\u7aef\u90fd\u5f97\u4e0d\u5230\u5904\u7406\u3002<\/p>\n<p>2\uff09.\u5bf9\u6bd4\u8f83\u957f\u7684\u804c\u8d23\u94fe\uff0c\u8bf7\u6c42\u7684\u5904\u7406\u53ef\u80fd\u6d89\u53ca\u591a\u4e2a\u5904\u7406\u5bf9\u8c61\uff0c\u7cfb\u7edf\u6027\u80fd\u5c06\u53d7\u5230\u4e00\u5b9a\u5f71\u54cd\u3002<\/p>\n<p>3\uff09.\u804c\u8d23\u94fe\u5efa\u7acb\u7684\u5408\u7406\u6027\u8981\u9760\u5ba2\u6237\u7aef\u6765\u4fdd\u8bc1\uff0c\u589e\u52a0\u4e86\u5ba2\u6237\u7aef\u7684\u590d\u6742\u6027\uff0c\u53ef\u80fd\u4f1a\u7531\u4e8e\u804c\u8d23\u94fe\u7684\u9519\u8bef\u8bbe\u7f6e\u800c\u5bfc\u81f4\u7cfb\u7edf\u51fa\u9519\uff0c\u5982\u53ef\u80fd\u4f1a\u9020\u6210\u5faa\u73af\u8c03\u7528\u3002<\/p>\n<h3>3\u3001\u8d23\u4efb\u94fe\u7ed3\u6784\u56fe<\/h3>\n<\/p>\n<p><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000043144518\" alt=\"\" title=\"\" loading=\"lazy\"><\/p>\n<\/p>\n<p><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000043144519\" alt=\"\" title=\"\" loading=\"lazy\"><\/p>\n<\/p>\n<h2>\u4e8c\u3001Dubbo\u4e2d\u7684\u8d23\u4efb\u94fe\u6a21\u5f0f<\/h2>\n<h3>1\u3001\u8fc7\u6ee4\u5668\u65e5\u5fd7<\/h3>\n<p>\u901a\u8fc7\u6253\u5370\u8fc7\u6ee4\u5668\u7684\u65e5\u5fd7\uff0c\u6211\u4eec\u53ef\u4ee5\u770b\u5230\u5728\u53d1\u5e03\u670d\u52a1\u7684\u8fc7\u7a0b\u4e2d\uff0c\u4f1a\u4f9d\u6b21\u7ecf\u8fc7dubbo\u7684\u6bcf\u4e2a\u8fc7\u6ee4\u5668\u7c7b\uff0c\u4ee5\u6b64\u6765\u4fdd\u8bc1\u670d\u52a1\u7684\u5b8c\u5584\u3002<\/p>\n<\/p>\n<p><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000043144520\" alt=\"\" title=\"\" loading=\"lazy\"><\/p>\n<\/p>\n<h3>2\u3001\u8fc7\u6ee4\u5668\u7b80\u56fe<\/h3>\n<p>dubbo\u901a\u8fc7\u5c06\u6bcf\u4e2a\u8fc7\u6ee4\u5668\u7c7bfilter\u5c01\u88c5\u6210dubbo\u7684\u6838\u5fc3\u6a21\u578binvoker\u8fdb\u884c\u7ec4\u88c5\uff0c\u6700\u7ec8\u5f62\u6210\u665a\u4e0a\u7684\u8fc7\u6ee4\u5668\u8d23\u4efb\u94fefilterChain\u3002<\/p>\n<\/p>\n<p><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000043144521\" alt=\"\" title=\"\" loading=\"lazy\"><\/p>\n<\/p>\n<h3>3\u3001\u8fc7\u6ee4\u5668\u7c7b\u56fe<\/h3>\n<p>Protocol\u662f\u6838\u5fc3\u6a21\u578binvoker\u66b4\u9732\u548c\u5f15\u7528\u7684\u4e3b\u529f\u80fd\u5165\u53e3\uff0c\u91c7\u7528SPI\u7684\u63a5\u53e3\uff0c\u4ed6\u7684\u4e24\u4e2a\u65b9\u6cd5export\u548crefer\u5206\u522b\u5bf9\u5e94provider\u548cconsumer\u7aef\u7684\u670d\u52a1\u529f\u80fd\uff0cProtocolFilterWapper\u5219\u662fDubbo\u7684\u8fc7\u6ee4\u5668\u7684\u4e3b\u8981\u5b9e\u73b0\u7c7b\uff0c\u901a\u8fc7\u91cd\u5199\u7684export\u548crefer\u6307\u5411buildInvokerChain\u65b9\u6cd5\uff0c\u5728buildInvokerChain\u4e2d\u8fdb\u884c\u8d23\u4efb\u94fe\u7684\u83b7\u53d6\u4e0e\u7ec4\u88c5\uff0c\u5728extensionLoader\u4e2d\u901a\u8fc7SPI\u83b7\u53d6Filter\u7684\u5404\u5b9e\u73b0\u7c7b\uff0c\u5e76\u901a\u8fc7ActivateComparator\u8fdb\u884c\u6392\u5e8f\uff0c\u6700\u7ec8\u5f62\u6210\u5b8c\u6574\u7684\u8d23\u4efb\u94fe\u3002<\/p>\n<\/p>\n<p><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000043144522\" alt=\"\" title=\"\" loading=\"lazy\"><\/p>\n<\/p>\n<h2>\u4e09\u3001Dubbo\u4e2d\u5404Filter\u8d23\u4efb\u4ecb\u7ecd<\/h2>\n<h3>1\u3001provider\u7528\u5230\u7684filter<\/h3>\n<\/p>\n<p><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000043144523\" alt=\"\" title=\"\" loading=\"lazy\"><\/p>\n<\/p>\n<h3>2\u3001consumer\u7528\u5230\u7684filter<\/h3>\n<\/p>\n<p><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000043144524\" alt=\"\" title=\"\" loading=\"lazy\"><\/p>\n<\/p>\n<h2>\u56db\u3001\u6e90\u7801\u63a2\u6790<\/h2>\n<p>\u8fdb\u5165\u5230\u6838\u5fc3\u7c7bProtocolFilterWrapper\u4e2d\uff0c\u5728\u5b9e\u73b0\u7c7b\u4e2dexport\u548crefer\uff0c\u90fd\u91c7\u7528\u76f8\u540c\u7684\u6784\u9020\u8d23\u4efb\u94fe\u65b9\u6cd5buildInvokerChain\uff0c\u53ea\u662f\u901a\u8fc7\u53c2\u6570group\u8fdb\u884c\u533a\u5206<\/p>\n<\/p>\n<p><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000043144525\" alt=\"\" title=\"\" loading=\"lazy\"><\/p>\n<\/p>\n<p>\u5728buildInvokerChain\u4e2d\uff0c\u901a\u8fc7getActivateExtension\u83b7\u53d6\u8fc7\u6ee4\u5668\u6570\u7ec4\uff0c\u5e76\u5728\u4e4b\u540e\u5c01\u88c5\u6210\u6838\u5fc3\u6a21\u578binvoker\u5e76\u7ec4\u88c5\u6210\u8d23\u4efb\u94fe<\/p>\n<pre><code>private static &lt;T&gt; Invoker&lt;T&gt; buildInvokerChain(final Invoker&lt;T&gt; invoker, String key, String group) {\n        Invoker&lt;T&gt; last = invoker;\n        \/\/ \u83b7\u5f97\u8fc7\u6ee4\u5668\u6570\u7ec4 \uff08\u5df2\u7ecf\u6392\u597d\u5e8f\u7684\uff09\n        List&lt;Filter&gt; filters = ExtensionLoader.getExtensionLoader(Filter.class).getActivateExtension(invoker.getUrl(), key, group);\n        \/\/ \u521b\u5efa\u5e26 Filter \u94fe\u7684 Invoker \u5bf9\u8c61\n        if (!filters.isEmpty()) {\n            for (int i = filters.size() - 1; i &gt;= 0; i--) {\n                final Filter filter = filters.get(i);\n                final Invoker&lt;T&gt; next = last;\n                last = new Invoker&lt;T&gt;() {\n\n                    @Override\n                    public Class&lt;T&gt; getInterface() {\n                        return invoker.getInterface();\n                    }\n\n                    @Override\n                    public URL getUrl() {\n                        return invoker.getUrl();\n                    }\n\n                    @Override\n                    public boolean isAvailable() {\n                        return invoker.isAvailable();\n                    }\n\n                    @Override\n                    public Result invoke(Invocation invocation) throws RpcException {\n                        return filter.invoke(next, invocation);\n                    }\n\n                    @Override\n                    public void destroy() {\n                        invoker.destroy();\n                    }\n\n                    @Override\n                    public String toString() {\n                        return invoker.toString();\n                    }\n                };\n            }\n        }\n        System.out.println(&quot;group:&quot; + group);\n        for (Filter filter : filters) {\n            System.out.println(filter.getClass());\n        }\n        return last;\n    }<\/code><\/pre>\n<p>getActivateExtension\u662f\u4e3b\u8981\u7684\u7ec4\u88c5\u903b\u8f91\uff0c\u4ed6\u5305\u542b\u83b7\u53d6\u4e0e\u6392\u5e8f\u7b49\u903b\u8f91<\/p>\n<p>\u9996\u5148\u8fdb\u884c\u5224\u65ad\u662f\u5426\u91c7\u7528\u7cfb\u7edf\u9ed8\u8ba4\u7684Filter\u8fc7\u6ee4\u5668\uff0c\u5e76\u5bf9\u6bcf\u4e00\u4e2a\u7cfb\u7edf\u8fc7\u6ee4\u5668\u8fdb\u884c\u6821\u9a8c\u662f\u5426\u79fb\u9664\uff0c\u7136\u540e\u5bf9\u7cfb\u7edf\u8fc7\u6ee4\u5668\u6392\u5e8f\uff0c\u518d\u901a\u8fc7\u6307\u5b9a\u7684\u53c2\u6570\uff0c\u589e\u52a0\u7528\u6237\u81ea\u5b9a\u4e49\u7684\u8fc7\u6ee4\u5668\u7ec4\u88c5\u8d23\u4efb\u94fe<\/p>\n<pre><code>\npublic List&lt;T&gt; getActivateExtension(URL url, String key, String group) {\n        \/\/ \u4ece Dubbo URL \u83b7\u5f97\u53c2\u6570\u503c\n        String value = url.getParameter(key);\n        \/\/ \u83b7\u5f97\u7b26\u5408\u81ea\u52a8\u6fc0\u6d3b\u6761\u4ef6\u7684\u62d3\u5c55\u5bf9\u8c61\u6570\u7ec4\n        return getActivateExtension(url, value == null || value.length() == 0 ? null : Constants.COMMA_SPLIT_PATTERN.split(value), group);\n    }\npublic List&lt;T&gt; getActivateExtension(URL url, String[] values, String group) {\n        List&lt;T&gt; exts = new ArrayList&lt;T&gt;();\n        \/\/\u6240\u6709\u7528\u6237\u81ea\u5df1\u914d\u7f6e\u7684filter\u4fe1\u606f\uff08\u6709\u4e9bFilter\u662f\u9ed8\u8ba4\u6fc0\u6d3b\u7684\uff0c\u6709\u4e9b\u662f\u914d\u7f6e\u6fc0\u6d3b\u7684\uff0c\u8fd9\u91cc\u7684names\u5c31\u6307\u7684\u914d\u7f6e\u6fc0\u6d3b\u7684filter\u4fe1\u606f\uff09\n        List&lt;String&gt; names = values == null ? new ArrayList&lt;String&gt;(0) : Arrays.asList(values);\n        \/\/ \u5904\u7406\u81ea\u52a8\u6fc0\u6d3b\u7684\u62d3\u5c55\u5bf9\u8c61\u4eec\n        \/\/ \u5224\u65ad\u4e0d\u5b58\u5728\u914d\u7f6e `&quot;-name&quot;` \u3002\u4f8b\u5982\uff0c&lt;dubbo:service filter=&quot;-default&quot; \/&gt; \uff0c\u4ee3\u8868\u79fb\u9664\u6240\u6709\u9ed8\u8ba4\u8fc7\u6ee4\u5668\u3002\n        if (!names.contains(Constants.REMOVE_VALUE_PREFIX + Constants.DEFAULT_KEY)) {\n            \/\/ \u83b7\u5f97\u62d3\u5c55\u5b9e\u73b0\u7c7b\u6570\u7ec4\n            getExtensionClasses();\n            \/\/ \u5faa\u73af\n            for (Map.Entry&lt;String, Activate&gt; entry : cachedActivates.entrySet()) {\n                \/\/name\u6307\u7684\u662fSPI\u8bfb\u53d6\u7684\u914d\u7f6e\u6587\u4ef6\u7684key\n                String name = entry.getKey();\n                Activate activate = entry.getValue();\n                if (isMatchGroup(group, activate.group())) { \/\/ \u5339\u914d\u5206\u7ec4\n                    \/\/ \u83b7\u5f97\u62d3\u5c55\u5bf9\u8c61\n                    T ext = getExtension(name);\n                    if (!names.contains(name) \/\/ \u4e0d\u5305\u542b\u5728\u81ea\u5b9a\u4e49\u914d\u7f6e\u91cc\u3002\u5982\u679c\u5305\u542b\uff0c\u4f1a\u5728\u4e0b\u9762\u7684\u4ee3\u7801\u5904\u7406\u3002\n                            &amp;&amp; !names.contains(Constants.REMOVE_VALUE_PREFIX + name) \/\/ \u5224\u65ad\u662f\u5426\u914d\u7f6e\u79fb\u9664\u3002\u4f8b\u5982 &lt;dubbo:service filter=&quot;-monitor&quot; \/&gt;\uff0c\u5219 MonitorFilter \u4f1a\u88ab\u79fb\u9664\n                            &amp;&amp; isActive(activate, url)) { \/\/ \u5224\u65ad\u662f\u5426\u6fc0\u6d3b\n                        exts.add(ext);\n                    }\n                }\n            }\n            \/\/ \u6392\u5e8f\n            Collections.sort(exts, ActivateComparator.COMPARATOR);\n        }\n        \/\/ \u5904\u7406\u81ea\u5b9a\u4e49\u914d\u7f6e\u7684\u62d3\u5c55\u5bf9\u8c61\u4eec\u3002\u4f8b\u5982\u5728 &lt;dubbo:service filter=&quot;demo&quot; \/&gt; \uff0c\u4ee3\u8868\u9700\u8981\u52a0\u5165 DemoFilter\n        List&lt;T&gt; usrs = new ArrayList&lt;T&gt;();\n        for (int i = 0; i &lt; names.size(); i++) {\n            String name = names.get(i);\n            if (!name.startsWith(Constants.REMOVE_VALUE_PREFIX) &amp;&amp; !names.contains(Constants.REMOVE_VALUE_PREFIX + name)) { \/\/ \u5224\u65ad\u975e\u79fb\u9664\u7684\n                \/\/ \u5c06\u914d\u7f6e\u7684\u81ea\u5b9a\u4e49\u5728\u81ea\u52a8\u6fc0\u6d3b\u7684\u62d3\u5c55\u5bf9\u8c61\u4eec\u524d\u9762\u3002\u4f8b\u5982\uff0c&lt;dubbo:service filter=&quot;demo,default,demo2&quot; \/&gt; \uff0c\u5219 DemoFilter \u5c31\u4f1a\u653e\u5728\u9ed8\u8ba4\u7684\u8fc7\u6ee4\u5668\u524d\u9762\u3002\n                if (Constants.DEFAULT_KEY.equals(name)) {\n                    if (!usrs.isEmpty()) {\n                        exts.addAll(0, usrs);\n                        usrs.clear();\n                    }\n                } else {\n                    \/\/ \u83b7\u5f97\u62d3\u5c55\u5bf9\u8c61\n                    T ext = getExtension(name);\n                    usrs.add(ext);\n                }\n            }\n        }\n        \/\/ \u6dfb\u52a0\u5230\u7ed3\u679c\u96c6\n        if (!usrs.isEmpty()) {\n            exts.addAll(usrs);\n        }\n        return exts;\n    }<\/code><\/pre>\n<p>\u7cfb\u7edf\u9ed8\u8ba4\u7684\u8fc7\u6ee4\u5668\u548cudf\u8fc7\u6ee4\u5668\u8fdb\u884c\u533a\u5206<\/p>\n<p>\u4ee5ContextFilter\u4e3a\u4f8b\uff0c\u7cfb\u7edf\u9ed8\u8ba4\u8fc7\u6ee4\u5668\u5305\u542bActivate\u6ce8\u89e3\uff0c\u7528\u4e8e\u6307\u5b9a\u6240\u5c5e\u5206\u7ec4\u4e0e\u6392\u5e8f\u6743\u91cd\uff0c\u7528\u6237\u81ea\u5df1\u5b9e\u73b0\u7684\u8fc7\u6ee4\u5668\u5219\u4e0d\u80fd\u6dfb\u52a0Activate\u6ce8\u89e3\u901a\u8fc7\u53d1\u5e03\u65f6\u6307\u5b9a\u6240\u9700\u7684\u8fc7\u6ee4\u5668<\/p>\n<\/p>\n<p><img decoding=\"async\" referrerpolicy=\"no-referrer\" src=\"https:\/\/segmentfault.com\/img\/remote\/1460000043144526\" alt=\"\" title=\"\" loading=\"lazy\"><\/p>\n<\/p>\n<p>\u6211\u4eec\u770b\u4e0b\u5177\u4f53\u7684\u6392\u5e8f\u6bd4\u8f83\u65b9\u6cd5\uff0c\u9996\u5148\u5224\u65adActivate\u6ce8\u89e3\u662f\u5426\u6307\u5b9abefore\u548cafter\u53c2\u6570\u7528\u6765\u6307\u5b9a\u6392\u5e8f\uff0c\u82e5\u4e0d\u5b58\u5728\u5219\u91c7\u7528order\u6743\u91cd\u8fdb\u884c\u6392\u5e8f<\/p>\n<pre><code>ActivateComparator.class\npublic int compare(Object o1, Object o2) {\n        \/\/ \u57fa\u672c\u6392\u5e8f\n        if (o1 == null &amp;&amp; o2 == null) {\n            return 0;\n        }\n        if (o1 == null) {\n            return -1;\n        }\n        if (o2 == null) {\n            return 1;\n        }\n        if (o1.equals(o2)) {\n            return 0;\n        }\n\n        Activate a1 = o1.getClass().getAnnotation(Activate.class);\n        Activate a2 = o2.getClass().getAnnotation(Activate.class);\n\n        \/\/ \u4f7f\u7528\u6ce8\u89e3\u7684 `after` \u548c `before` \u5c5e\u6027\uff0c\u6392\u5e8f\n        if ((a1.before().length &gt; 0 || a1.after().length &gt; 0 || a2.before().length &gt; 0 || a2.after().length &gt; 0) \/\/ (a1 \u6216 a2) \u5b58\u5728 (`after` \u6216 `before`) \u5c5e\u6027\u3002\n                &amp;&amp; o1.getClass().getInterfaces().length &gt; 0 &amp;&amp; o1.getClass().getInterfaces()[0].isAnnotationPresent(SPI.class)) { \/\/ \u5b9e\u73b0\u7684\u63a5\u53e3\uff0c\u6709 @SPI \u6ce8\u89e3\u3002\n            \/\/ \u83b7\u5f97\u62d3\u5c55\u52a0\u8f7d\u5668\n            ExtensionLoader&lt;?&gt; extensionLoader = ExtensionLoader.getExtensionLoader(o1.getClass().getInterfaces()[0]);\n            \/\/ \u4ee5 a1 \u7684\u89c6\u89d2\uff0c\u8fdb\u884c\u4e00\u6b21\u6bd4\u8f83\n            if (a1.before().length &gt; 0 || a1.after().length &gt; 0) {\n                String n2 = extensionLoader.getExtensionName(o2.getClass());\n                for (String before : a1.before()) {\n                    if (before.equals(n2)) {\n                        return -1;\n                    }\n                }\n                for (String after : a1.after()) {\n                    if (after.equals(n2)) {\n                        return 1;\n                    }\n                }\n            }\n            \/\/ \u4ee5 a2 \u7684\u89c6\u89d2\uff0c\u8fdb\u884c\u4e00\u6b21\u6bd4\u8f83\u3002\n            if (a2.before().length &gt; 0 || a2.after().length &gt; 0) {\n                String n1 = extensionLoader.getExtensionName(o1.getClass());\n                for (String before : a2.before()) {\n                    if (before.equals(n1)) {\n                        return 1;\n                    }\n                }\n                for (String after : a2.after()) {\n                    if (after.equals(n1)) {\n                        return -1;\n                    }\n                }\n            }\n        }\n\n        \/\/ \u4f7f\u7528\u6ce8\u89e3\u7684 `order` \u5c5e\u6027\uff0c\u6392\u5e8f\u3002\n        int n1 = a1 == null ? 0 : a1.order();\n        int n2 = a2 == null ? 0 : a2.order();\n        \/\/ never return 0 even if n1 equals n2, otherwise, o1 and o2 will override each other in collection like HashSet\n        return n1 &gt; n2 ? 1 : -1;\n    }<\/code><\/pre>\n<p><strong>\u603b\u7ed3\uff1a<\/strong><br \/>\u8d23\u4efb\u94fe\u6a21\u5f0f\u662f\u8bbe\u8ba1\u6a21\u5f0f\u4e2d\u7b80\u5355\u4e14\u5e38\u89c1\u7684\u8bbe\u8ba1\u6a21\u5f0f\uff0c\u53ef\u80fd\u6211\u4eec\u65e5\u5e38\u4e2d\u4e5f\u4f1a\u7ecf\u5e38\u5e94\u7528\u8d23\u4efb\u94fe\u6a21\u5f0f\uff0cdubbo\u4e2d\u7684\u8d23\u4efb\u94fe\u6a21\u5f0f\u5c06\u7075\u6d3b\u6027\u53d1\u6325\u7684\u5f88\u5145\u5206\uff0c\u4e0d\u8bba\u662f\u4ece\u5206\u7ec4\u6982\u5ff5\u3001\u901a\u8fc7\u6ce8\u89e3\u6307\u5b9a\u6392\u5e8f\u7684\u4f18\u5148\u7ea7\u3001\u6bcf\u4e2afilter\u7684\u662f\u5426\u79fb\u9664 \u7b49\uff0c\u5c06\u6bcf\u4e2afilter\u505a\u6210\u4e86\u53ef\u63d2\u62d4\u7684\uff0c\u51cf\u5c11\u5bf9\u4ee3\u7801\u7684\u4fb5\u5165\u6027\uff0c\u8fd9\u70b9\u662f\u975e\u5e38\u503c\u5f97\u6211\u4eec\u5b66\u4e60\u7684\u3002<\/p>\n<p><a href=\"https:\/\/segmentfault.com\/a\/1190000043144516\">https:\/\/segmentfault.com\/a\/1190000043144516<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4f5c\u8005\uff1a\u5468\u53ef\u5f3a \u4e00\u3001\u8d23\u4efb\u94fe\u6a21\u5f0f\u7b80\u4ecb 1\u3001\u8d23\u4efb\u94fe\u6a21\u5f0f\u5b9a\u4e49 \u8d23\u4efb\u94fe\uff08Chain of Responsibility\uff09 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[4],"tags":[],"class_list":["post-10007006","post","type-post","status-publish","format-standard","hentry","category-share"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts\/10007006","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=10007006"}],"version-history":[{"count":0,"href":"https:\/\/itmax.cn\/index.php?rest_route=\/wp\/v2\/posts\/10007006\/revisions"}],"wp:attachment":[{"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=10007006"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=10007006"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/itmax.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=10007006"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}