一：以属性文件方式配置mysql时，需要在启动类加注解
1.1 问题详情：1.2 解决方式： 二：restTemplate以服务名访问其他服务时，UnknownHostException
2.1 问题详情：2.2 解决方式： 三：Feign传参问题
3.1 问题详情：3.2 解决方式： 四：ribbon负载均衡问题
4.1 问题详情：4.2 解决方式： 五：消费端使用服务端feign Bean加载问题
5.1 问题详情：5.2 解决方式：
一：以属性文件方式配置mysql时，需要在启动类加注解 1.1 问题详情：Description: A component required a bean of type 'xxx.mapper.XianJieAddressMapper' that could not be found. Action: Consider defining a bean of type 'xxx.mapper.XianJieAddressMapper' in your configuration.1.2 解决方式：
启动类上添加注解@MapperScan("xxx.mapper")
二：restTemplate以服务名访问其他服务时，UnknownHostException
2.1 问题详情：
java.net.UnknownHostException: LL-XIANJIE at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:196) ~[na:1.8.0_291] at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:162) ~[na:1.8.0_291] at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:394) ~[na:1.8.0_291] at java.net.Socket.connect(Socket.java:606) ~[na:1.8.0_291] at java.net.Socket.connect(Socket.java:555) ~[na:1.8.0_291] at sun.net.NetworkClient.doConnect(NetworkClient.java:180) ~[na:1.8.0_291] at sun.net.www.http.HttpClient.openServer(HttpClient.java:463) ~[na:1.8.0_291] at sun.net.www.http.HttpClient.openServer(HttpClient.java:558) ~[na:1.8.0_291] at sun.net.www.http.HttpClient.2.2 解决方式：(HttpClient.java:242) ~[na:1.8.0_291] at sun.net.www.http.HttpClient.New(HttpClient.java:339) ~[na:1.8.0_291] at sun.net.www.http.HttpClient.New(HttpClient.java:357) ~[na:1.8.0_291] at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:1226) ~[na:1.8.0_291] at sun.net.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1162) ~[na:1.8.0_291] at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:1056) ~[na:1.8.0_291] at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:990) ~[na:1.8.0_291] at org.springframework.http.client.SimpleBufferingClientHttpRequest.executeInternal(SimpleBufferingClientHttpRequest.java:76) ~[spring-web-5.3.14.jar:5.3.14] at org.springframework.http.client.AbstractBufferingClientHttpRequest.executeInternal(AbstractBufferingClientHttpRequest.java:48) ~[spring-web-5.3.14.jar:5.3.14] at org.springframework.http.client.AbstractClientHttpRequest.execute(AbstractClientHttpRequest.java:66) ~[spring-web-5.3.14.jar:5.3.14] at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:776) ~[spring-web-5.3.14.jar:5.3.14] at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:711) ~[spring-web-5.3.14.jar:5.3.14] at org.springframework.web.client.RestTemplate.getForEntity(RestTemplate.java:361) ~[spring-web-5.3.14.jar:5.3.14] at cn.liulin.llrenjianjie.controller.AddressController.getXianJieAddressInfo(AddressController.java:28) ~[classes/:na] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_291] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_291] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_291] at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_291] at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) ~[spring-web-5.3.14.jar:5.3.14] at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150) ~[spring-web-5.3.14.jar:5.3.14] at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:117) ~[spring-webmvc-5.3.14.jar:5.3.14] at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895) ~[spring-webmvc-5.3.14.jar:5.3.14] at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808) ~[spring-webmvc-5.3.14.jar:5.3.14] at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.3.14.jar:5.3.14] at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1067) ~[spring-webmvc-5.3.14.jar:5.3.14] at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:963) ~[spring-webmvc-5.3.14.jar:5.3.14] at org.springframework.web.servlet.frameworkServlet.processRequest(frameworkServlet.java:1006) ~[spring-webmvc-5.3.14.jar:5.3.14] at org.springframework.web.servlet.frameworkServlet.doGet(frameworkServlet.java:898) ~[spring-webmvc-5.3.14.jar:5.3.14] at javax.servlet.http.HttpServlet.service(HttpServlet.java:655) ~[tomcat-embed-core-9.0.56.jar:4.0.FR] at org.springframework.web.servlet.frameworkServlet.service(frameworkServlet.java:883) ~[spring-webmvc-5.3.14.jar:5.3.14] at javax.servlet.http.HttpServlet.service(HttpServlet.java:764) ~[tomcat-embed-core-9.0.56.jar:4.0.FR] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227) ~[tomcat-embed-core-9.0.56.jar:9.0.56] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.56.jar:9.0.56] at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.56.jar:9.0.56] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.56.jar:9.0.56] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.56.jar:9.0.56] at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.3.14.jar:5.3.14] at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.14.jar:5.3.14] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.56.jar:9.0.56] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.56.jar:9.0.56] at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.3.14.jar:5.3.14] at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.14.jar:5.3.14] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.56.jar:9.0.56] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.56.jar:9.0.56] at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.3.14.jar:5.3.14] at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.14.jar:5.3.14] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.56.jar:9.0.56] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.56.jar:9.0.56] at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:197) ~[tomcat-embed-core-9.0.56.jar:9.0.56] at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) [tomcat-embed-core-9.0.56.jar:9.0.56] at org.apache.catalina.authenticator.Authenticatorbase.invoke(Authenticatorbase.java:540) [tomcat-embed-core-9.0.56.jar:9.0.56] at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135) [tomcat-embed-core-9.0.56.jar:9.0.56] at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.56.jar:9.0.56] at org.apache.catalina.core.StandardEnginevalve.invoke(StandardEnginevalve.java:78) [tomcat-embed-core-9.0.56.jar:9.0.56] at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:357) [tomcat-embed-core-9.0.56.jar:9.0.56] at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:382) [tomcat-embed-core-9.0.56.jar:9.0.56] at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) [tomcat-embed-core-9.0.56.jar:9.0.56] at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:895) [tomcat-embed-core-9.0.56.jar:9.0.56] at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1732) [tomcat-embed-core-9.0.56.jar:9.0.56] at org.apache.tomcat.util.net.SocketProcessorbase.run(SocketProcessorbase.java:49) [tomcat-embed-core-9.0.56.jar:9.0.56] at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) [tomcat-embed-core-9.0.56.jar:9.0.56] at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) [tomcat-embed-core-9.0.56.jar:9.0.56] at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.56.jar:9.0.56] at java.lang.Thread.run(Thread.java:748) [na:1.8.0_291]
#添加负载均衡注解@LoadBalanced
@Bean
@LoadBalanced
public RestTemplate restTemplate() {
return new RestTemplate();
}
三：Feign传参问题
3.1 问题详情：
- feign传参无法接收参数；feign传参参数过长丢失；
- Feign传参如果不加@RequestParam注解。参数默认使用@RequestBody方式进行传递，参数以JSON形式包裹在请求体中。所以最好在传参时，添加注解@RequestParam或者@RequestBody，且@RequestBody只能使用一次。使用@RequestParam，参数是附加在请求路径后，且参数长度有限制，大约在1205个字符左右，所以长字符参数建议用@RequestBody。
RestTemplate调用 No instances available for xxx4.2 解决方式：
如果你的代码pom文件中已经存在五：消费端使用服务端feign Bean加载问题 5.1 问题详情：那就不要再使用 spring-cloud-starter-ribbon 或者 spring-cloud-starter-netflix-ribbon 因为上面的配置已经带入了负载均衡相关功能，使用下面的单独ribbon配置反而会导致负载均衡冲突失效 org.springframework.cloud spring-cloud-starter-netflix-eureka-client
Description: A component required a bean of type 'xxx.XianJieUserClient' that could not be found. Action: Consider defining a bean of type 'xxx.XianJieUserClient' in your configuration.5.2 解决方式：
在消费端以feign形式调用服务端接口时，由于需要注入服务端bean实例 @Resource private XianJieUserClient xianJieUserClient; 所以需要在启动类上面加入对应服务端bean所在类路径扫描注解 @EnableFeignClients(basePackages = "xxx.client")
