{"id":756,"date":"2023-08-15T16:03:29","date_gmt":"2023-08-15T08:03:29","guid":{"rendered":"http:\/\/www.liuyd.cc\/?p=756"},"modified":"2023-08-15T16:49:14","modified_gmt":"2023-08-15T08:49:14","slug":"feignclient-%e4%b8%ad%ef%bc%8c%e6%96%b9%e6%b3%95%e8%bf%94%e5%9b%9e%e5%80%bc%e4%b8%ba-void-%e4%b8%8d%e8%bf%9b-decoder-%e7%9a%84%e5%8e%9f%e5%9b%a0%e5%8f%8a%e8%a7%a3%e5%86%b3%e5%8a%9e%e6%b3%95","status":"publish","type":"post","link":"http:\/\/www.liuyd.cc\/?p=756","title":{"rendered":"FeignClient \u4e2d\uff0c\u65b9\u6cd5\u8fd4\u56de\u503c\u4e3a void \u4e0d\u8fdb Decoder \u7684\u539f\u56e0\u53ca\u89e3\u51b3\u529e\u6cd5"},"content":{"rendered":"\n<p>\u57fa\u4e8e <code>SynchronousMethodHandler<\/code> \u5904\u7406\u5668\uff0c\u6765\u770b\u4e0b\u6267\u884c http \u8bf7\u6c42\u7684\u8fc7\u7a0b\u548cdecode\u903b\u8f91\uff08<strong>\u4ec5\u4fdd\u7559\u5173\u952e\u4ee3\u7801<\/strong>\uff09<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>Object executeAndDecode(RequestTemplate template, Options options) throws Throwable {\n    \/\/ \u521b\u5efa\u8bf7\u6c42\n    Request request = targetRequest(template);\n\n    \/\/ \u53d1\u8d77\u8bf7\u6c42\uff0c\u5e76\u6784\u5efa\u54cd\u5e94\n    Response response = client.execute(request, options);\n    response = response.toBuilder()\n          .request(request)\n          .requestTemplate(template)\n          .build();\n\n    \/\/ decoder != null\uff0c\u6267\u884c decoder \u903b\u8f91\n    if (decoder != null) {\n        return responseInterceptor.aroundDecode(new InvocationContext(decoder, metadata.returnType(), response));\n    }\n\n    \/\/ \u5426\u5219\u6267\u884c asyncResponseHandler\n    CompletableFuture&lt;Object&gt; resultFuture = new CompletableFuture&lt;&gt;();\n    asyncResponseHandler.handleResponse(resultFuture, metadata.configKey(), response,\n        metadata.returnType(), elapsedTime);\n}<\/code><\/pre>\n\n\n\n<p>\u5173\u4e8e decoder \u5c5e\u6027\u6765\u81ea\u4e8e\u6784\u9020\u6ce8\u5165\uff0c\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>private SynchronousMethodHandler(Target&lt;?&gt; target, Client client, Retryer retryer,\n      List&lt;RequestInterceptor&gt; requestInterceptors, ResponseInterceptor responseInterceptor,\n      Logger logger, Logger.Level logLevel, MethodMetadata metadata,\n      RequestTemplate.Factory buildTemplateFromArgs, Options options,\n      Decoder decoder, ErrorDecoder errorDecoder, boolean dismiss404,\n      boolean closeAfterDecode, ExceptionPropagationPolicy propagationPolicy,\n      boolean forceDecoding) {\n\n    \/\/ \u3002\u3002\u3002\u7701\u7565N\u884c\n\n    if (forceDecoding) {\n      \/\/ internal only: usual handling will be short-circuited, and all responses will be passed to\n      \/\/ decoder directly!\n      this.decoder = decoder;\n      this.asyncResponseHandler = null;\n    } else {\n      this.decoder = null;\n      this.asyncResponseHandler = new AsyncResponseHandler(logLevel, logger, decoder, errorDecoder,\n          dismiss404, closeAfterDecode, responseInterceptor);\n    }\n  }<\/code><\/pre>\n\n\n\n<p>\u5e38\u89c4\u60c5\u51b5\u4e0b\uff0c\u4f7f\u7528 <strong>Feign.Builder<\/strong> \u521d\u59cb\u5316 <strong>SynchronousMethodHandler <\/strong>\u65f6\uff0c<strong>forceDecoding \u4f20\u5165\u4e3a false<\/strong>\uff0c\u4e5f\u5c31\u662f\u8bf4\u6784\u9020\u53c2\u6570\u4e2d\u7684 decoder \u5373\u4f7f\u6709\u503c\uff0c\u4e5f\u6ca1\u6709\u76f4\u63a5\u8d4b\u503c\u7ed9 this.decoder\uff0c\u800c\u662f\u4f20\u5165\u5230\u4e86 <strong>new AsyncResponseHandler<\/strong>\u3002\u6240\u4ee5\u5728\u4e0a\u9762\u6267\u884c <strong>#executeAndDecode<\/strong> \u65b9\u6cd5\u65f6\uff0c\u5b9e\u9645\u4e0a\u662f\u8c03\u7528\u4e86 <strong>asyncResponseHandler.handleResponse<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>void handleResponse(CompletableFuture&lt;Object&gt; resultFuture, String configKey, Response response, Type returnType, long elapsedTime) {\n    \/\/ \u3002\u3002\u3002\u7701\u7565N\u884c\n    else if (response.status() &gt;= 200 &amp;&amp; response.status() &lt; 300) {\n        if (isVoidType(returnType)) {\n            resultFuture.complete(null);\n        } else {\n            final Object result = decode(response, returnType);\n            shouldClose = closeAfterDecode;\n            resultFuture.complete(result);\n        }\n    }\n}<\/code><\/pre>\n\n\n\n<p>\u5f53http\u72b6\u6001\u7801\u5728 [200, 300) \u4e2d\u95f4\u65f6\uff08\u5e38\u89c4\u6211\u4eec\u90fd\u662f <strong>200\u6b63\u5e38<\/strong> \u72b6\u6001\u7801\uff09<\/p>\n\n\n\n<p><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-red-color\">\u5219\u8fdb\u884c isVoidType(returnType) \u5224\u65ad\uff0c\u5982\u679c\u662f void \u8fd4\u56de\u503c\uff0c\u5219 resultFuture.complete(null); \u5c31\u5b8c\u4e8b\u4e86\uff0c\u4e0d\u4f1a\u8fdb\u5165 decode \uff01\uff01\uff01<\/mark><\/strong> <\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u89e3\u51b3\u65b9\u6848\uff1a<\/h3>\n\n\n\n<p><strong>1\uff09\u8fd4\u56de\u503c\u4e0d\u4f7f\u7528 void<\/strong> \u3010\u4e0d\u63a8\u8350\u3011<\/p>\n\n\n\n<p>\u8fd4\u56de\u503c\u4e0d\u4f7f\u7528void\uff0c\u800c\u662f\u63d0\u4f9b\u4e00\u4e2avoid\u5305\u88c5\u7c7b\uff0c\u5728decoder\u4e2d\u9488\u5bf9\u5305\u88c5\u7c7b\u76f4\u63a5\u8df3\u8fc7<\/p>\n\n\n\n<p>\u4e0d\u63a8\u8350\u539f\u56e0\uff1a\u5bf9\u4e8e\u65b0\u9879\u76ee\u800c\u8a00\u8fd8\u53ef\u4ee5\uff0c\u8001\u9879\u76ee\u5df2\u7ecf\u5b58\u5728\u7684void\u65b9\u6cd5\uff0c\u8fd8\u9700\u8981\u6539\u9020\u6210\u672c<\/p>\n\n\n\n<p><strong>2\uff09\u5f3a\u5236\u542f\u7528 forceDecoding<\/strong>\u3010\u4e0d\u63a8\u8350\u3011<\/p>\n\n\n\n<p>\u5728\u521b\u5efa\u4ee3\u7406\u5bf9\u8c61\u524d\uff0c\u53ef\u4ee5\u6267\u884c\u81ea\u5b9a\u4e49\uff0c\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\/\/ customizers\napplyBuildCustomizers(context, builder);\n\nprivate void applyBuildCustomizers(FeignContext context, Feign.Builder builder) {\n    Map&lt;String, FeignBuilderCustomizer&gt; customizerMap = \n                  context.getInstances(contextId, FeignBuilderCustomizer.class);\n    if (customizerMap != null) {\n       customizerMap.values().stream()\n              .sorted(AnnotationAwareOrderComparator.INSTANCE)\n              .forEach(feignBuilderCustomizer -&gt; feignBuilderCustomizer.customize(builder));\n    }\n    additionalCustomizers.forEach(customizer -&gt; customizer.customize(builder));\n}<\/code><\/pre>\n\n\n\n<p>\u4e5f\u5c31\u662f\u8bf4\uff0c\u5b9e\u73b0 <code>FeignBuilderCustomizer<\/code> \u63a5\u53e3\uff0c\u5373\u53ef\u5728\u521b\u5efa\u4ee3\u7406\u5bf9\u8c61\u524d\u62ff\u5230 builder<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\/**\n * Internal - used to indicate that the decoder should be immediately called\n *\/\nBuilder forceDecoding() {\n    this.forceDecoding = true;\n    return this;\n}<\/code><\/pre>\n\n\n\n<p>\u7531\u4e8e forceDecoding() \u975e public\uff0c\u56e0\u6b64\u9700\u8981\u4f7f\u7528\u53cd\u5c04\u6765\u8bbe\u7f6e\u503c<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>public class PilotFeignDecodeBuilderCustomizer implements FeignBuilderCustomizer {\n    @Override\n    public void customize(Feign.Builder builder) {\n        ReflectUtil.setFieldValue(builder, \"forceDecoding\", true);\n    }\n}<\/code><\/pre>\n\n\n\n<p>\u4e0d\u63a8\u8350\u539f\u56e0\uff1aasyncResponseHandler \u65e0\u6cd5\u88ab\u6267\u884c\uff0c\u5219\u5176\u4e2d\u7684\u65e5\u5fd7\u8bb0\u5f55\u3001body.close() \u7b49\u90fd\u9700\u8981decoder\u6765\u505a<\/p>\n\n\n\n<p><strong>3\u3001\u4ee3\u7406 Contract\u3010\u63a8\u8350\u3011<\/strong><\/p>\n\n\n\n<p>\u548c <strong>1\uff09\u8fd4\u56de\u503c\u4e0d\u4f7f\u7528 void<\/strong> \u7684\u601d\u60f3\u4e00\u81f4\uff0c\u53ea\u4e0d\u8fc7\u5bf9\u4e8e void \u6216\u8005 Void \u7684\u8fd4\u56de\u503c\uff0c\u505a\u4e86\u4e00\u5c42\u81ea\u52a8\u5305\u88c5<\/p>\n\n\n\n<p>\u539f\u7406\uff1a\u5728 Feign.Builder \u4e2d\u5b58\u5728 Contract \u5c5e\u6027\uff0c\u521b\u5efa FeignContractHolder \u5bf9 Contract \u505a\u4ee3\u7406\uff0c\u8fd9\u6837\u5728\u521b\u5efa FeignClient Proxy \u8fc7\u7a0b\u4e2d\uff0c\u5bf9\u4e8e target \u7684\u89e3\u6790\u5de5\u4f5c\u5219\u4ea4\u7ed9 FeignContractHolder \u6765\u505a\uff0c\u5728FeignContractHolder \u4e2d\u4ecd\u65e7\u4f7f\u7528\u539f\u6765\u7684Contract \u8fdb\u884c\u89e3\u6790\uff0cFeignContractHolder \u5219\u5bf9\u89e3\u6790\u7ed3\u679c\u505a\u904d\u5386\uff0c\u5982\u679c\u5b58\u5728 void \u6216\u8005 Void\uff0c\u5219\u8bbe\u5b9a\u4e3a\u5305\u88c5\u7c7b<\/p>\n\n\n\n<p>\u7b2c\u4e00\u6b65\uff1a\u521b\u5efa\u4e00\u4e2a FeignContractHolder\uff0c\u7528\u6765\u505a contract \u4ee3\u7406\uff0c\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>import feign.Contract;\n\n@AllArgsConstructor\npublic class FeignContractHolder implements Contract {\n    \/\/ \u4ee3\u7406\u5bf9\u8c61\n    private final Contract delegate;\n\n    @Override\n    public List&lt;MethodMetadata> parseAndValidateMetadata(Class&lt;?> targetType) {\n        List&lt;MethodMetadata> metadatas = delegate.parseAndValidateMetadata(targetType);\n\n        \/\/ \u5faa\u73af\u904d\u5386\u5904\u7406\uff0c\u5982\u679c\u662f void \u6216\u8005 Void\uff0c\u5219\u5305\u88c5\u4e00\u4e0b\n        if (CollUtil.isNotEmpty(metadatas)) {\n            metadatas.forEach(item -> {\n                if (item.returnType() == void.class || item.returnType() == Void.class) {\n                    item.returnType(VoidWrapper.class);\n                }\n            });\n        }\n\n        return metadatas;\n    }\n}<\/code><\/pre>\n\n\n\n<p>\u7b2c\u4e8c\u6b65\uff1a\u5728 FeignBuilderCustomizer \u4e2d\u521b\u5efaPilotFeignContractHolder<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\nimport feign.Contract;\nimport feign.Feign;\nimport org.springframework.cloud.openfeign.FeignBuilderCustomizer;\n\n\/**\n * Feign Builder Customizer.\n * &lt;p>\n * 1\u3001\u542f\u7528 PilotFeignContractHolder\uff0c\u7528\u6765\u4ee3\u7406 Contract\n *\/\npublic class FeignDecodeVoidBuilderCustomizer implements FeignBuilderCustomizer {\n    @Override\n    public void customize(Feign.Builder builder) {\n        \/\/ \u53cd\u5c04\u62ff\u5230 contract\n        Contract originalContract = (Contract) ReflectUtil.getFieldValue(builder, \"contract\");\n        \/\/ \u521b\u5efa PilotFeignContractHolder\uff0c\u7528\u4e8e\u4ee3\u7406 originalContract\n        builder.contract(new PilotFeignContractHolder(originalContract));\n    }\n}<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>\u57fa\u4e8e SynchronousMethodHandler \u5904\u7406\u5668\uff0c\u6765\u770b\u4e0b\u6267\u884c http \u8bf7\u6c42\u7684\u8fc7\u7a0b\u548cdecode\u903b\u8f91\uff08\u4ec5\u4fdd\u7559\u5173\u952e\u4ee3\u7801\uff09 \u5173\u4e8e decoder \u5c5e\u6027\u6765\u81ea\u4e8e\u6784\u9020\u6ce8\u5165\uff0c\u5982\u4e0b\uff1a \u5e38\u89c4\u60c5\u51b5\u4e0b\uff0c\u4f7f\u7528 Feign.Builder \u521d\u59cb\u5316 S [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":408,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[15],"tags":[24],"topic":[],"class_list":["post-756","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-java","tag-feign"],"_links":{"self":[{"href":"http:\/\/www.liuyd.cc\/index.php?rest_route=\/wp\/v2\/posts\/756","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.liuyd.cc\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.liuyd.cc\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.liuyd.cc\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.liuyd.cc\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=756"}],"version-history":[{"count":59,"href":"http:\/\/www.liuyd.cc\/index.php?rest_route=\/wp\/v2\/posts\/756\/revisions"}],"predecessor-version":[{"id":837,"href":"http:\/\/www.liuyd.cc\/index.php?rest_route=\/wp\/v2\/posts\/756\/revisions\/837"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/www.liuyd.cc\/index.php?rest_route=\/wp\/v2\/media\/408"}],"wp:attachment":[{"href":"http:\/\/www.liuyd.cc\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=756"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.liuyd.cc\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=756"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.liuyd.cc\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=756"},{"taxonomy":"topic","embeddable":true,"href":"http:\/\/www.liuyd.cc\/index.php?rest_route=%2Fwp%2Fv2%2Ftopic&post=756"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}