说明：记录一次使用Feign远程调用的错误，错误信息如下：
},Server stats: [[Server:192.168.222.1:8082; Zone:UNKNOWN; Total Requests:0; Successive connection failure:0; Total blackout seconds:0; Last connection made:Thu Jan 01 08:00:00 CST 1970; First connection made: Thu Jan 01 08:00:00 CST 1970; Active Connections:0; total failure count in last (1000) msecs:0; average resp time:0.0; 90 percentile resp time:0.0; 95 percentile resp time:0.0; min resp time:0.0; max resp time:0.0; stddev resp time:0.0]
]}ServerList:com.alibaba.cloud.nacos.ribbon.NacosServerList@468179dd
2024-03-10 21:14:43.591 ERROR 19744 --- [nio-8081-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is feign.codec.DecodeException: Could not extract response: no suitable HttpMessageConverter found for response type [class com.hezy.pojo.User] and content type [text/plain;charset=UTF-8]] with root cause
org.springframework.web.client.UnknownContentTypeException: Could not extract response: no suitable HttpMessageConverter found for response type [class com.hezy.pojo.User] and content type [text/plain;charset=UTF-8]
at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:126) ~[spring-web-5.2.13.RELEASE.jar:5.2.13.RELEASE]
at org.springframework.cloud.openfeign.support.SpringDecoder.decode(SpringDecoder.java:59) ~[spring-cloud-openfeign-core-2.2.5.RELEASE.jar:2.2.5.RELEASE]
at org.springframework.cloud.openfeign.support.ResponseEntityDecoder.decode(ResponseEntityDecoder.java:62) ~[spring-cloud-openfeign-core-2.2.5.RELEASE.jar:2.2.5.RELEASE]
at feign.optionals.OptionalDecoder.decode(OptionalDecoder.java:36) ~[feign-core-10.10.1.jar:na]
at feign.AsyncResponseHandler.decode(AsyncResponseHandler.java:115) ~[feign-core-10.10.1.jar:na]
at feign.AsyncResponseHandler.handleResponse(AsyncResponseHandler.java:87) ~[feign-core-10.10.1.jar:na]
at feign.SynchronousMethodHandler.executeAndDecode(SynchronousMethodHandler.java:138) ~[feign-core-10.10.1.jar:na]
at feign.SynchronousMethodHandler.invoke(SynchronousMethodHandler.java:89) ~[feign-core-10.10.1.jar:na]
at feign.ReflectiveFeign$FeignInvocationHandler.invoke(ReflectiveFeign.java:100) ~[feign-core-10.10.1.jar:na]
at com.sun.proxy.$Proxy78.getUserById(Unknown Source) ~[na:na]
at com.hezy.service.impl.OrderServiceImpl.getOrderById(OrderServiceImpl.java:24) ~[classes/:na]
at com.hezy.controller.OrderController.getOrder(OrderController.java:16) ~[classes/:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na]
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) ~[spring-web-5.2.13.RELEASE.jar:5.2.13.RELEASE]
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.2.13.RELEASE.jar:5.2.13.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:105) ~[spring-webmvc-5.2.13.RELEASE.jar:5.2.13.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:878) ~[spring-webmvc-5.2.13.RELEASE.jar:5.2.13.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:792) ~[spring-webmvc-5.2.13.RELEASE.jar:5.2.13.RELEASE]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.2.13.RELEASE.jar:5.2.13.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) ~[spring-webmvc-5.2.13.RELEASE.jar:5.2.13.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) ~[spring-webmvc-5.2.13.RELEASE.jar:5.2.13.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.2.13.RELEASE.jar:5.2.13.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.2.13.RELEASE.jar:5.2.13.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:626) ~[tomcat-embed-core-9.0.43.jar:4.0.FR]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.2.13.RELEASE.jar:5.2.13.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:733) ~[tomcat-embed-core-9.0.43.jar:4.0.FR]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.43.jar:9.0.43]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.2.13.RELEASE.jar:5.2.13.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.13.RELEASE.jar:5.2.13.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.2.13.RELEASE.jar:5.2.13.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.13.RELEASE.jar:5.2.13.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.2.13.RELEASE.jar:5.2.13.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.13.RELEASE.jar:5.2.13.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:346) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:887) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1684) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.43.jar:9.0.43]
at java.base/java.lang.Thread.run(Thread.java:834) ~[na:na]
翻译后说，无法提取响应
参考了下面这篇文章：
- 参考文章
这篇文章中说将FeignClient中的返回类型改为String，改后之后确实可以了。在分析我的情况之后，我发现两边的返回类型不一致。服务那边返回的是String，而我这边使用一个实体类对象接收的。
如下：
解决：俩边保持一致就可以了。回头复盘，是我直接将UserService粘贴过来作为FeignClient，没有注意到接口的返回类型。
