采用springcloud-alibaba整合rabbion使用DiscoveryClient调用restful时遇到的一个问题，报错如下：
1 D:javaDevlepTooljava1.8jdk1.8injava.exe -XX:TieredStopAtLevel=1 -noverify -Dspring.output.ansi.enabled=always -Dcom.sun.management.jmxremote -Dspring.liveBeansView.mbeanDomain -Dspring.application.admin.enabled=true "-javaagent:D:javaDevlepToolIDEAIntelliJ IDEA 2018.2.8libidea_rt.jar=57241:D:javaDevlepToolIDEAIntelliJ IDEA 2018.2.8in" -Dfile.encoding=UTF-8 -classpath D:javaDevlepTooljava1.8jdk1.8jrelibcharsets.jar;D:javaDevlepTooljava1.8jdk1.8jrelibdeploy.jar;D:javaDevlepTooljava1.8jdk1.8jrelibextaccess-bridge-64.jar;D:javaDevlepTooljava1.8jdk1.8jrelibextcldrdata.jar;D:javaDevlepTooljava1.8jdk1.8jrelibextdnsns.jar;D:javaDevlepTooljava1.8jdk1.8jrelibextjaccess.jar;D:javaDevlepTooljava1.8jdk1.8jrelibextjfxrt.jar;D:javaDevlepTooljava1.8jdk1.8jrelibextlocaledata.jar;D:javaDevlepTooljava1.8jdk1.8jrelibext ashorn.jar;D:javaDevlepTooljava1.8jdk1.8jrelibextsunec.jar;D:javaDevlepTooljava1.8jdk1.8jrelibextsunjce_provider.jar;D:javaDevlepTooljava1.8jdk1.8jrelibextsunmscapi.jar;D:javaDevlepTooljava1.8jdk1.8jrelibextsunpkcs11.jar;D:javaDevlepTooljava1.8jdk1.8jrelibextzipfs.jar;D:javaDevlepTooljava1.8jdk1.8jrelibjavaws.jar;D:javaDevlepTooljava1.8jdk1.8jrelibjce.jar;D:javaDevlepTooljava1.8jdk1.8jrelibjfr.jar;D:javaDevlepTooljava1.8jdk1.8jrelibjfxswt.jar;D:javaDevlepTooljava1.8jdk1.8jrelibjsse.jar;D:javaDevlepTooljava1.8jdk1.8jrelibmanagement-agent.jar;D:javaDevlepTooljava1.8jdk1.8jrelibplugin.jar;D:javaDevlepTooljava1.8jdk1.8jrelib esources.jar;D:javaDevlepTooljava1.8jdk1.8jrelib t.jar;D:drawnbluespringcloud-alibabauser argetclasses;D:javaEnvironment epoorgspringframeworkootspring-boot-starter-web2.1.6.RELEASEspring-boot-starter-web-2.1.6.RELEASE.jar;D:javaEnvironment epoorgspringframeworkootspring-boot-starter-json2.1.6.RELEASEspring-boot-starter-json-2.1.6.RELEASE.jar;D:javaEnvironment epocomfasterxmljacksoncorejackson-databind2.9.9jackson-databind-2.9.9.jar;D:javaEnvironment epocomfasterxmljacksoncorejackson-annotations2.9.0jackson-annotations-2.9.0.jar;D:javaEnvironment epocomfasterxmljacksoncorejackson-core2.9.9jackson-core-2.9.9.jar;D:javaEnvironment epocomfasterxmljacksondatatypejackson-datatype-jdk82.9.9jackson-datatype-jdk8-2.9.9.jar;D:javaEnvironment epocomfasterxmljacksondatatypejackson-datatype-jsr3102.9.9jackson-datatype-jsr310-2.9.9.jar;D:javaEnvironment epocomfasterxmljacksonmodulejackson-module-parameter-names2.9.9jackson-module-parameter-names-2.9.9.jar;D:javaEnvironment epoorgspringframeworkootspring-boot-starter-tomcat2.1.6.RELEASEspring-boot-starter-tomcat-2.1.6.RELEASE.jar;D:javaEnvironment epoorgapache omcatembed omcat-embed-core9.0.21 omcat-embed-core-9.0.21.jar;D:javaEnvironment epoorgapache omcatembed omcat-embed-el9.0.21 omcat-embed-el-9.0.21.jar;D:javaEnvironment epoorgapache omcatembed omcat-embed-websocket9.0.21 omcat-embed-websocket-9.0.21.jar;D:javaEnvironment epoorghibernatevalidatorhibernate-validator6.0.17.Finalhibernate-validator-6.0.17.Final.jar;D:javaEnvironment epojavaxvalidationvalidation-api2.0.1.Finalvalidation-api-2.0.1.Final.jar;D:javaEnvironment epoorgjbossloggingjboss-logging3.3.2.Finaljboss-logging-3.3.2.Final.jar;D:javaEnvironment epocomfasterxmlclassmate1.4.0classmate-1.4.0.jar;D:javaEnvironment epoorgspringframeworkspring-web5.1.8.RELEASEspring-web-5.1.8.RELEASE.jar;D:javaEnvironment epoorgspringframeworkspring-beans5.1.8.RELEASEspring-beans-5.1.8.RELEASE.jar;D:javaEnvironment epoorgspringframeworkspring-webmvc5.1.8.RELEASEspring-webmvc-5.1.8.RELEASE.jar;D:javaEnvironment epoorgspringframeworkspring-aop5.1.8.RELEASEspring-aop-5.1.8.RELEASE.jar;D:javaEnvironment epoorgspringframeworkspring-context5.1.8.RELEASEspring-context-5.1.8.RELEASE.jar;D:javaEnvironment epoorgspringframeworkspring-expression5.1.8.RELEASEspring-expression-5.1.8.RELEASE.jar;D:javaEnvironment epoorgslf4jslf4j-api1.7.26slf4j-api-1.7.26.jar;D:javaEnvironment epoorgspringframeworkspring-core5.1.8.RELEASEspring-core-5.1.8.RELEASE.jar;D:javaEnvironment epoorgspringframeworkspring-jcl5.1.8.RELEASEspring-jcl-5.1.8.RELEASE.jar;D:drawnbluespringcloud-alibabacommon argetclasses;D:javaEnvironment epoorgspringframeworkcloudspring-cloud-starter-alibaba-nacos-discovery .9.0.RELEASEspring-cloud-starter-alibaba-nacos-discovery-0.9.0.RELEASE.jar;D:javaEnvironment epoorgspringframeworkcloudspring-cloud-alibaba-nacos-discovery .9.0.RELEASEspring-cloud-alibaba-nacos-discovery-0.9.0.RELEASE.jar;D:javaEnvironment epocomalibaba acos acos-client1.0.0 acos-client-1.0.0.jar;D:javaEnvironment epocomalibaba acos acos-common1.0.0 acos-common-1.0.0.jar;D:javaEnvironment epocommons-iocommons-io2.2commons-io-2.2.jar;D:javaEnvironment epoorgapachecommonscommons-lang33.8.1commons-lang3-3.8.1.jar;D:javaEnvironment epocomalibaba acos acos-api1.0.0 acos-api-1.0.0.jar;D:javaEnvironment epocomalibabafastjson1.2.47fastjson-1.2.47.jar;D:javaEnvironment epocomgoogleguavaguava19.0guava-19.0.jar;D:javaEnvironment epocommons-codeccommons-codec1.11commons-codec-1.11.jar;D:javaEnvironment epoioprometheussimpleclient .5.0simpleclient-0.5.0.jar;D:javaEnvironment epoorgspringframeworkcloudspring-cloud-commons2.1.2.RELEASEspring-cloud-commons-2.1.2.RELEASE.jar;D:javaEnvironment epoorgspringframeworksecurityspring-security-crypto5.1.5.RELEASEspring-security-crypto-5.1.5.RELEASE.jar;D:javaEnvironment epoorgspringframeworkcloudspring-cloud-context2.1.2.RELEASEspring-cloud-context-2.1.2.RELEASE.jar;D:javaEnvironment epoorgspringframeworkcloudspring-cloud-starter-netflix-ribbon2.1.2.RELEASEspring-cloud-starter-netflix-ribbon-2.1.2.RELEASE.jar;D:javaEnvironment epoorgspringframeworkcloudspring-cloud-starter2.1.2.RELEASEspring-cloud-starter-2.1.2.RELEASE.jar;D:javaEnvironment epoorgspringframeworksecurityspring-security-rsa1.0.7.RELEASEspring-security-rsa-1.0.7.RELEASE.jar;D:javaEnvironment epoorgouncycastlecpkix-jdk15on1.60cpkix-jdk15on-1.60.jar;D:javaEnvironment epoorgouncycastlecprov-jdk15on1.60cprov-jdk15on-1.60.jar;D:javaEnvironment epoorgspringframeworkcloudspring-cloud-netflix-ribbon2.1.2.RELEASEspring-cloud-netflix-ribbon-2.1.2.RELEASE.jar;D:javaEnvironment epoorgspringframeworkcloudspring-cloud-netflix-archaius2.1.2.RELEASEspring-cloud-netflix-archaius-2.1.2.RELEASE.jar;D:javaEnvironment epoorgspringframeworkcloudspring-cloud-starter-netflix-archaius2.1.2.RELEASEspring-cloud-starter-netflix-archaius-2.1.2.RELEASE.jar;D:javaEnvironment epocom etflixarchaiusarchaius-core .7.6archaius-core-0.7.6.jar;D:javaEnvironment epocomgooglecodefindbugsjsr3053.0.1jsr305-3.0.1.jar;D:javaEnvironment epocommons-configurationcommons-configuration1.8commons-configuration-1.8.jar;D:javaEnvironment epocom etflix ibbon ibbon2.3.0 ibbon-2.3.0.jar;D:javaEnvironment epocom etflix ibbon ibbon-transport2.3.0 ibbon-transport-2.3.0.jar;D:javaEnvironment epoio eactivex xnetty-contexts .4.9 xnetty-contexts-0.4.9.jar;D:javaEnvironment epoio eactivex xnetty-servo .4.9 xnetty-servo-0.4.9.jar;D:javaEnvironment epocom etflixhystrixhystrix-core1.5.18hystrix-core-1.5.18.jar;D:javaEnvironment epoorghdrhistogramHdrHistogram2.1.9HdrHistogram-2.1.9.jar;D:javaEnvironment epojavaxinjectjavax.inject1javax.inject-1.jar;D:javaEnvironment epoio eactivex xnetty .4.9 xnetty-0.4.9.jar;D:javaEnvironment epocom etflix ibbon ibbon-core2.3.0 ibbon-core-2.3.0.jar;D:javaEnvironment epocommons-langcommons-lang2.6commons-lang-2.6.jar;D:javaEnvironment epocom etflix ibbon ibbon-httpclient2.3.0 ibbon-httpclient-2.3.0.jar;D:javaEnvironment epocommons-collectionscommons-collections3.2.2commons-collections-3.2.2.jar;D:javaEnvironment epoorgapachehttpcomponentshttpclient4.5.9httpclient-4.5.9.jar;D:javaEnvironment epoorgapachehttpcomponentshttpcore4.4.11httpcore-4.4.11.jar;D:javaEnvironment epocomsunjerseyjersey-client1.19.1jersey-client-1.19.1.jar;D:javaEnvironment epocomsunjerseyjersey-core1.19.1jersey-core-1.19.1.jar;D:javaEnvironment epojavaxws sjsr311-api1.1.1jsr311-api-1.1.1.jar;D:javaEnvironment epocomsunjerseycontribsjersey-apache-client41.19.1jersey-apache-client4-1.19.1.jar;D:javaEnvironment epocom etflixservoservo-core .12.21servo-core-0.12.21.jar;D:javaEnvironment epocom etflix etflix-commons etflix-commons-util .3.0 etflix-commons-util-0.3.0.jar;D:javaEnvironment epocom etflix ibbon ibbon-loadbalancer2.3.0 ibbon-loadbalancer-2.3.0.jar;D:javaEnvironment epocom etflix etflix-commons etflix-statistics .1.1 etflix-statistics-0.1.1.jar;D:javaEnvironment epoio eactivex xjava1.3.8 xjava-1.3.8.jar;D:javaEnvironment epoorgspringframeworkootspring-boot-starter2.1.6.RELEASEspring-boot-starter-2.1.6.RELEASE.jar;D:javaEnvironment epoorgspringframeworkootspring-boot2.1.6.RELEASEspring-boot-2.1.6.RELEASE.jar;D:javaEnvironment epoorgspringframeworkootspring-boot-autoconfigure2.1.6.RELEASEspring-boot-autoconfigure-2.1.6.RELEASE.jar;D:javaEnvironment epoorgspringframeworkootspring-boot-starter-logging2.1.6.RELEASEspring-boot-starter-logging-2.1.6.RELEASE.jar;D:javaEnvironment epochqoslogbacklogback-classic1.2.3logback-classic-1.2.3.jar;D:javaEnvironment epochqoslogbacklogback-core1.2.3logback-core-1.2.3.jar;D:javaEnvironment epoorgapachelogginglog4jlog4j-to-slf4j2.11.2log4j-to-slf4j-2.11.2.jar;D:javaEnvironment epoorgapachelogginglog4jlog4j-api2.11.2log4j-api-2.11.2.jar;D:javaEnvironment epoorgslf4jjul-to-slf4j1.7.26jul-to-slf4j-1.7.26.jar;D:javaEnvironment epojavaxannotationjavax.annotation-api1.3.2javax.annotation-api-1.3.2.jar;D:javaEnvironment epoorgyamlsnakeyaml1.23snakeyaml-1.23.jar com.drawnblue.UserApplication 2 2019-08-20 21:49:16.138 INFO 2896 --- [ main] trationDelegate$BeanPostProcessorChecker : Bean 'org.springframework.cloud.autoconfigure.ConfigurationPropertiesRebinderAutoConfiguration' of type [org.springframework.cloud.autoconfigure.ConfigurationPropertiesRebinderAutoConfiguration$$EnhancerBySpringCGLIB$$39244cdd] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying) 3 4 . ____ _ __ _ _ 5 /\ / ___'_ __ _ _(_)_ __ __ _ 6 ( ( )\___ | '_ | '_| | '_ / _` | 7 \/ ___)| |_)| | | | | || (_| | ) ) ) ) 8 ' |____| .__|_| |_|_| |_\__, | / / / / 9 =========|_|==============|___/=/_/_/_/ 10 :: Spring Boot :: (v2.1.6.RELEASE) 11 12 2019-08-20 21:49:17.557 INFO 2896 --- [ main] com.drawnblue.UserApplication : No active profile set, falling back to default profiles: default 13 2019-08-20 21:49:18.392 INFO 2896 --- [ main] o.s.cloud.context.scope.GenericScope : BeanFactory id=f26475a6-8ec9-369b-81c6-da54b33473b9 14 2019-08-20 21:49:18.422 INFO 2896 --- [ main] trationDelegate$BeanPostProcessorChecker : Bean 'org.springframework.cloud.autoconfigure.ConfigurationPropertiesRebinderAutoConfiguration' of type [org.springframework.cloud.autoconfigure.ConfigurationPropertiesRebinderAutoConfiguration$$EnhancerBySpringCGLIB$$39244cdd] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying) 15 2019-08-20 21:49:18.758 INFO 2896 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8002 (http) 16 2019-08-20 21:49:18.793 INFO 2896 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat] 17 2019-08-20 21:49:18.793 INFO 2896 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.21] 18 2019-08-20 21:49:18.974 INFO 2896 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext 19 2019-08-20 21:49:18.974 INFO 2896 --- [ main] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 1390 ms 20 2019-08-20 21:49:21.276 WARN 2896 --- [ main] c.n.c.sources.URLConfigurationSource : No URLs will be polled as dynamic configuration sources. 21 2019-08-20 21:49:21.276 INFO 2896 --- [ main] c.n.c.sources.URLConfigurationSource : To enable URLs as dynamic configuration sources, define System property archaius.configurationSource.additionalUrls or make config.properties available on classpath. 22 2019-08-20 21:49:21.284 WARN 2896 --- [ main] c.n.c.sources.URLConfigurationSource : No URLs will be polled as dynamic configuration sources. 23 2019-08-20 21:49:21.284 INFO 2896 --- [ main] c.n.c.sources.URLConfigurationSource : To enable URLs as dynamic configuration sources, define System property archaius.configurationSource.additionalUrls or make config.properties available on classpath. 24 2019-08-20 21:49:21.600 INFO 2896 --- [ main] o.s.s.concurrent.ThreadPoolTaskExecutor : Initializing ExecutorService 'applicationTaskExecutor' 25 2019-08-20 21:49:22.061 INFO 2896 --- [ main] o.s.s.c.ThreadPoolTaskScheduler : Initializing ExecutorService 26 2019-08-20 21:49:22.344 INFO 2896 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8002 (http) with context path '' 27 2019-08-20 21:49:22.430 INFO 2896 --- [ main] o.s.c.a.n.registry.NacosServiceRegistry : nacos registry, user 192.168.179.1:8002 register finished 28 2019-08-20 21:49:22.434 INFO 2896 --- [ main] com.drawnblue.UserApplication : Started UserApplication in 11.304 seconds (JVM running for 13.348) 29 2019-08-20 21:49:27.223 INFO 2896 --- [nio-8002-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring DispatcherServlet 'dispatcherServlet' 30 2019-08-20 21:49:27.225 INFO 2896 --- [nio-8002-exec-1] o.s.web.servlet.DispatcherServlet : Initializing Servlet 'dispatcherServlet' 31 2019-08-20 21:49:27.238 INFO 2896 --- [nio-8002-exec-1] o.s.web.servlet.DispatcherServlet : Completed initialization in 13 ms 32 ======================[org.springframework.cloud.alibaba.nacos.NacosServiceInstance@2bcfc07f, org.springframework.cloud.alibaba.nacos.NacosServiceInstance@291f102] 33 http://192.168.179.1:8011/userService/findById/{id}------targetUrl org.springframework.web.client.RestTemplate@3910fe11 34 2019-08-20 21:49:29.040 INFO 2896 --- [nio-8002-exec-1] c.netflix.config.ChainedDynamicProperty : Flipping property: 192.168.179.1.ribbon.ActiveConnectionsLimit to use NEXT property: niws.loadbalancer.availabilityFilteringRule.activeConnectionsLimit = 2147483647 35 2019-08-20 21:49:29.096 INFO 2896 --- [nio-8002-exec-1] c.netflix.loadbalancer.BaseLoadBalancer : Client: 192.168.179.1 instantiated a LoadBalancer: DynamicServerListLoadBalancer:{NFLoadBalancer:name=192.168.179.1,current list of Servers=[],Load balancer stats=Zone stats: {},Server stats: []}ServerList:null 36 2019-08-20 21:49:29.107 INFO 2896 --- [nio-8002-exec-1] c.n.l.DynamicServerListLoadBalancer : Using serverListUpdater PollingServerListUpdater 37 2019-08-20 21:49:29.120 INFO 2896 --- [nio-8002-exec-1] c.n.l.DynamicServerListLoadBalancer : DynamicServerListLoadBalancer for client 192.168.179.1 initialized: DynamicServerListLoadBalancer:{NFLoadBalancer:name=192.168.179.1,current list of Servers=[],Load balancer stats=Zone stats: {},Server stats: []}ServerList:org.springframework.cloud.alibaba.nacos.ribbon.NacosServerList@623249f7 38 2019-08-20 21:49:29.175 ERROR 2896 --- [nio-8002-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 java.lang.IllegalStateException: No instances available for 192.168.179.1] with root cause 39 40 java.lang.IllegalStateException: No instances available for 192.168.179.1 41 at org.springframework.cloud.netflix.ribbon.RibbonLoadBalancerClient.execute(RibbonLoadBalancerClient.java:119) ~[spring-cloud-netflix-ribbon-2.1.2.RELEASE.jar:2.1.2.RELEASE] 42 at org.springframework.cloud.netflix.ribbon.RibbonLoadBalancerClient.execute(RibbonLoadBalancerClient.java:99) ~[spring-cloud-netflix-ribbon-2.1.2.RELEASE.jar:2.1.2.RELEASE] 43 at org.springframework.cloud.client.loadbalancer.LoadBalancerInterceptor.intercept(LoadBalancerInterceptor.java:58) ~[spring-cloud-commons-2.1.2.RELEASE.jar:2.1.2.RELEASE] 44 at org.springframework.http.client.InterceptingClientHttpRequest$InterceptingRequestExecution.execute(InterceptingClientHttpRequest.java:92) ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] 45 at org.springframework.http.client.InterceptingClientHttpRequest.executeInternal(InterceptingClientHttpRequest.java:76) ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] 46 at org.springframework.http.client.AbstractBufferingClientHttpRequest.executeInternal(AbstractBufferingClientHttpRequest.java:48) ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] 47 at org.springframework.http.client.AbstractClientHttpRequest.execute(AbstractClientHttpRequest.java:53) ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] 48 at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:735) ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] 49 at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:670) ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] 50 at org.springframework.web.client.RestTemplate.getForEntity(RestTemplate.java:338) ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] 51 at com.drawnblue.usercontroller.UserController.findById2(UserController.java:41) ~[classes/:na] 52 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_161] 53 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_161] 54 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_161] 55 at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_161] 56 at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] 57 at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] 58 at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104) ~[spring-webmvc-5.1.8.RELEASE.jar:5.1.8.RELEASE] 59 at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:892) ~[spring-webmvc-5.1.8.RELEASE.jar:5.1.8.RELEASE] 60 at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:797) ~[spring-webmvc-5.1.8.RELEASE.jar:5.1.8.RELEASE] 61 at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.1.8.RELEASE.jar:5.1.8.RELEASE] 62 at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1039) ~[spring-webmvc-5.1.8.RELEASE.jar:5.1.8.RELEASE] 63 at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942) ~[spring-webmvc-5.1.8.RELEASE.jar:5.1.8.RELEASE] 64 at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005) ~[spring-webmvc-5.1.8.RELEASE.jar:5.1.8.RELEASE] 65 at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:897) ~[spring-webmvc-5.1.8.RELEASE.jar:5.1.8.RELEASE] 66 at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) ~[tomcat-embed-core-9.0.21.jar:9.0.21] 67 at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882) ~[spring-webmvc-5.1.8.RELEASE.jar:5.1.8.RELEASE] 68 at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[tomcat-embed-core-9.0.21.jar:9.0.21] 69 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.21.jar:9.0.21] 70 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.21.jar:9.0.21] 71 at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.21.jar:9.0.21] 72 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.21.jar:9.0.21] 73 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.21.jar:9.0.21] 74 at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] 75 at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:109) ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] 76 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.21.jar:9.0.21] 77 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.21.jar:9.0.21] 78 at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:92) ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] 79 at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:109) ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] 80 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.21.jar:9.0.21] 81 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.21.jar:9.0.21] 82 at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93) ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] 83 at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:109) ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] 84 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.21.jar:9.0.21] 85 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.21.jar:9.0.21] 86 at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] 87 at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:109) ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] 88 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.21.jar:9.0.21] 89 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.21.jar:9.0.21] 90 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.21.jar:9.0.21] 91 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-9.0.21.jar:9.0.21] 92 at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490) [tomcat-embed-core-9.0.21.jar:9.0.21] 93 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) [tomcat-embed-core-9.0.21.jar:9.0.21] 94 at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.21.jar:9.0.21] 95 at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.21.jar:9.0.21] 96 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.21.jar:9.0.21] 97 at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408) [tomcat-embed-core-9.0.21.jar:9.0.21] 98 at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-9.0.21.jar:9.0.21] 99 at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:853) [tomcat-embed-core-9.0.21.jar:9.0.21] 100 at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1587) [tomcat-embed-core-9.0.21.jar:9.0.21] 101 at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.21.jar:9.0.21] 102 at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_161] 103 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_161] 104 at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.21.jar:9.0.21] 105 at java.lang.Thread.run(Thread.java:748) [na:1.8.0_161]
主要代码如下：
package com.drawnblue;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;
@SpringBootApplication
@EnableDiscoveryClient
public class UserApplication {
public static void main(String[] args) {
SpringApplication.run(UserApplication.class, args);
}
@Bean
@LoadBalanced
public RestTemplate restTemplate() {
return new RestTemplate();
}
}
conotroller
1 package com.drawnblue.usercontroller; 2 3 import com.drawnblue.entity.User; 4 import org.springframework.beans.factory.annotation.Autowired; 5 import org.springframework.cloud.client.ServiceInstance; 6 import org.springframework.cloud.client.discovery.DiscoveryClient; 7 import org.springframework.http.ResponseEntity; 8 import org.springframework.web.bind.annotation.GetMapping; 9 import org.springframework.web.bind.annotation.PathVariable; 10 import org.springframework.web.bind.annotation.RestController; 11 import org.springframework.web.client.RestTemplate; 12 13 import java.util.List; 14 15 @RestController 16 public class UserController { 17 @Autowired 18 private RestTemplate restTemplate; 19 @Autowired 20 private DiscoveryClient discoveryClient; 21 @GetMapping("/test/{id}") 22 public User findById(@PathVariable Long id) { 23 System.out.println("調用kaishi"); 24 ResponseEntity<User> body = this.restTemplate.getForEntity("http://user-service/userService/findById/"+id, User.class); 25 System.out.println("調用完成"); 26 return body.getBody(); 27 } 28 @GetMapping("/getInstances") 29 public List<ServiceInstance> getInstances(){ 30 return this.discoveryClient.getInstances("user-service"); 31 } 32 @GetMapping("/test1/{id}") 33 public User findById2(@PathVariable Long id){ 34 List<ServiceInstance> instances = discoveryClient.getInstances("user-service"); 35 System.out.println("======================"+instances); 36 String targetURL = instances.stream() 37 .map(instance -> instance.getUri().toString()+"/userService/findById/{id}") 38 .findFirst().orElseThrow(()-> new IllegalArgumentException("当前没有实例")); 39 40 System.out.println(targetURL+"------targetUrl"+" "+this.restTemplate); 41 ResponseEntity<User> body = this.restTemplate.getForEntity(targetURL,User.class,1); 42 return body.getBody(); 43 } 44 }
根据日志中的url和传值id=1直接在浏览器都能返回，但是调用改接口就报错：
最终发现是因为
@LoadBalanced
的原因。
加了了注解 @LoadBalanced 之后，我们的r estTemplate 会走这个类RibbonLoadBalancerClient，断点进入了如下的页面，serverid必须是我们访问的服务名称 ，当我们直接输入ip的时候获取的server是null，就会抛出异常
当我把这个注释掉以后，重启一下，再去访问ok.
再次访问：
手写的随机负载均衡代码如下：
1 @RequestMapping("/getUserT/{id}") 2 public User getUserByRestTemplate(@PathVariable("id") String id){ 3 List<ServiceInstance> list = this.discoveryClient.getInstances("user-service"); 4 List<String> targetUrls = list.stream().map(serviceInstance -> serviceInstance.getUri().toString()).collect(Collectors.toList()); 5 int i = new Random().nextInt(targetUrls.size()); 6 System.out.println("-------"+targetUrls.get(i).toString()); 7 ResponseEntity<User> response = restTemplate.getForEntity(targetUrls.get(i)+"/test/{id}",User.class,id); 8 return response.getBody(); 9 }
运行日志：
说明实现了随机，并没有轮询访问