springboot发布dubbo服务注册到nacos

喜欢ヅ旅行 2023-09-29 09:28 121阅读 0赞

#### 目录 ####

*  dubbo注册服务到nacos的pom依赖
 *  使用dubbo发布rest服务报错
 *  解决403 unknown user错误
 *  如何把dubbo服务注册到nacos指定的命名空间?
 *  dubbo消费端
 *  dubbo发布rest服务
 *   *  启动报错
     *  解决办法
     *  再次报错
     *  解决办法
 *  完善消费者
 *  总结

## dubbo注册服务到nacos的pom依赖 ##

理论上只需要2个最核心的依赖

<dependency>
        <groupId>org.apache.dubbo</groupId>
        <artifactId>dubbo-spring-boot-starter</artifactId>
        <version>${dubbo-spring-boot-starter.version}</version>
    </dependency>
    <dependency>
        <groupId>com.alibaba.cloud</groupId>
        <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
    </dependency>

但是**dubbo**会用到**nacos-api**，**spring-cloud-starter-alibaba-nacos-discovery**中依赖的**nacos-client**版本太低，需要单独指定**nacos-client**版本，否则在**org.apache.dubbo:dubbo**中使用**nacos-api**时会抛**NoSuchMethodError**，所以在**pom**中还需要添加

<dependency>
        <groupId>com.alibaba.nacos</groupId>
        <artifactId>nacos-client</artifactId>
        <version>${nacos-client.version}</version>
    </dependency>

2022-04-05 19:09:39.667  WARN 15740 --- [           main] o.a.d.c.deploy.FrameworkModelCleaner     :  [DUBBO] ExtensionDirector is destroyed, dubbo version: 3.0.6, current host: 192.168.1.4
    
    java.lang.IllegalStateException: ExtensionDirector is destroyed
    	at org.apache.dubbo.common.extension.ExtensionDirector.checkDestroyed(ExtensionDirector.java:156) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.common.extension.ExtensionDirector.getExtensionLoader(ExtensionDirector.java:67) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.common.extension.ExtensionAccessor.getExtensionLoader(ExtensionAccessor.java:27) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.rpc.model.ScopeModelUtil.getExtensionLoader(ScopeModelUtil.java:102) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.registry.integration.RegistryProtocol.getRegistry(RegistryProtocol.java:391) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.registry.integration.RegistryProtocol$ExporterChangeableWrapper.unexport(RegistryProtocol.java:892) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.registry.integration.RegistryProtocol.destroy(RegistryProtocol.java:636) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.rpc.protocol.ProtocolListenerWrapper.destroy(ProtocolListenerWrapper.java:89) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.qos.protocol.QosProtocolWrapper.destroy(QosProtocolWrapper.java:90) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.rpc.cluster.filter.ProtocolFilterWrapper.destroy(ProtocolFilterWrapper.java:79) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.rpc.protocol.ProtocolSerializationWrapper.destroy(ProtocolSerializationWrapper.java:57) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.deploy.FrameworkModelCleaner.destroyProtocols(FrameworkModelCleaner.java:55) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.deploy.FrameworkModelCleaner.destroyFrameworkResources(FrameworkModelCleaner.java:43) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.deploy.FrameworkModelCleaner.onDestroy(FrameworkModelCleaner.java:35) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.deploy.FrameworkModelCleaner.onDestroy(FrameworkModelCleaner.java:29) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.rpc.model.ScopeModel.notifyDestroy(ScopeModel.java:133) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.rpc.model.FrameworkModel.onDestroy(FrameworkModel.java:125) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.rpc.model.ScopeModel.destroy(ScopeModel.java:110) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.rpc.model.FrameworkModel.tryDestroy(FrameworkModel.java:257) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.rpc.model.ApplicationModel.onDestroy(ApplicationModel.java:277) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.rpc.model.ScopeModel.destroy(ScopeModel.java:110) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.rpc.model.ApplicationModel.tryDestroy(ApplicationModel.java:351) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.rpc.model.ModuleModel.onDestroy(ModuleModel.java:124) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.rpc.model.ScopeModel.destroy(ScopeModel.java:110) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.spring.context.DubboDeployApplicationListener.onContextClosedEvent(DubboDeployApplicationListener.java:130) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.spring.context.DubboDeployApplicationListener.onApplicationEvent(DubboDeployApplicationListener.java:102) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.spring.context.DubboDeployApplicationListener.onApplicationEvent(DubboDeployApplicationListener.java:45) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:176) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:169) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:143) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:421) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:378) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.doClose(AbstractApplicationContext.java:1058) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.doClose(ServletWebServerApplicationContext.java:172) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.context.support.AbstractApplicationContext.close(AbstractApplicationContext.java:1021) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.boot.builder.ParentContextCloserApplicationListener$ContextCloserListener.onApplicationEvent(ParentContextCloserApplicationListener.java:94) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.builder.ParentContextCloserApplicationListener$ContextCloserListener.onApplicationEvent(ParentContextCloserApplicationListener.java:82) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:176) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:169) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:143) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:421) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:378) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.doClose(AbstractApplicationContext.java:1058) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.close(AbstractApplicationContext.java:1021) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.cloud.bootstrap.BootstrapApplicationListener$CloseContextOnFailureApplicationListener.onApplicationEvent(BootstrapApplicationListener.java:497) ~[spring-cloud-context-3.1.1.jar:3.1.1]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:176) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:169) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:143) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:421) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:378) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.boot.context.event.EventPublishingRunListener.failed(EventPublishingRunListener.java:124) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplicationRunListeners.callFailedListener(SpringApplicationRunListeners.java:96) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplicationRunListeners.lambda$failed$7(SpringApplicationRunListeners.java:87) ~[spring-boot-2.6.6.jar:2.6.6]
    	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511) ~[na:na]
    	at org.springframework.boot.SpringApplicationRunListeners.doWithListeners(SpringApplicationRunListeners.java:120) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplicationRunListeners.failed(SpringApplicationRunListeners.java:86) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplication.handleRunFailure(SpringApplication.java:790) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:313) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1312) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301) ~[spring-boot-2.6.6.jar:2.6.6]
    	at com.wen3.dubbonacos.DemoProviderApplication.main(DemoProviderApplication.java:15) ~[classes/:na]

## 使用dubbo发布rest服务报错 ##

2022-04-05 19:09:48.830 ERROR 15740 --- [           main] o.s.boot.SpringApplication               : Application run failed
    
    java.lang.IllegalStateException: No such extension org.apache.dubbo.rpc.Protocol by name rest, possible causes: 
    (1) rest=org.apache.dubbo.rpc.protocol.rest.RestProtocol:
    java.lang.IllegalStateException: Failed to load extension class (interface: interface org.apache.dubbo.rpc.Protocol, class line: rest=org.apache.dubbo.rpc.protocol.rest.RestProtocol) in jar:file:/G:/repository/org/apache/dubbo/dubbo/3.0.6/dubbo-3.0.6.jar!/META-INF/dubbo/internal/org.apache.dubbo.rpc.Protocol, cause: org/jboss/resteasy/client/jaxrs/ClientHttpEngine
    java.lang.IllegalStateException: Failed to load extension class (interface: interface org.apache.dubbo.rpc.Protocol, class line: rest=org.apache.dubbo.rpc.protocol.rest.RestProtocol) in jar:file:/G:/repository/org/apache/dubbo/dubbo/3.0.6/dubbo-3.0.6.jar!/META-INF/dubbo/internal/org.apache.dubbo.rpc.Protocol, cause: org/jboss/resteasy/client/jaxrs/ClientHttpEngine
    	at org.apache.dubbo.common.extension.ExtensionLoader.loadResource(ExtensionLoader.java:1052)
    	at org.apache.dubbo.common.extension.ExtensionLoader.loadFromClass(ExtensionLoader.java:1019)
    	at org.apache.dubbo.common.extension.ExtensionLoader.lambda$loadDirectory$4(ExtensionLoader.java:1007)
    	at java.base/java.util.LinkedHashMap.forEach(LinkedHashMap.java:721)
    	at java.base/java.util.Collections$UnmodifiableMap.forEach(Collections.java:1553)
    	at org.apache.dubbo.common.extension.ExtensionLoader.loadDirectory(ExtensionLoader.java:1006)
    	at org.apache.dubbo.common.extension.ExtensionLoader.loadDirectory(ExtensionLoader.java:943)
    	at org.apache.dubbo.common.extension.ExtensionLoader.loadExtensionClasses(ExtensionLoader.java:931)
    	at org.apache.dubbo.common.extension.ExtensionLoader.getExtensionClasses(ExtensionLoader.java:913)
    	at org.apache.dubbo.common.extension.ExtensionLoader.getAdaptiveExtensionClass(ExtensionLoader.java:1243)
    	at org.apache.dubbo.common.extension.ExtensionLoader.createAdaptiveExtension(ExtensionLoader.java:1231)
    	at org.apache.dubbo.common.extension.ExtensionLoader.getAdaptiveExtension(ExtensionLoader.java:713)
    	at org.apache.dubbo.config.ServiceConfig.postProcessAfterScopeModelChanged(ServiceConfig.java:154)
    	at org.apache.dubbo.config.AbstractConfig.setScopeModel(AbstractConfig.java:395)
    	at org.apache.dubbo.config.AbstractConfig.<init>(AbstractConfig.java:117)
    	at org.apache.dubbo.config.AbstractMethodConfig.<init>(AbstractMethodConfig.java:103)
    	at org.apache.dubbo.config.AbstractInterfaceConfig.<init>(AbstractInterfaceConfig.java:192)
    	at org.apache.dubbo.config.AbstractServiceConfig.<init>(AbstractServiceConfig.java:132)
    	at org.apache.dubbo.config.ServiceConfigBase.<init>(ServiceConfigBase.java:84)
    	at org.apache.dubbo.config.ServiceConfig.<init>(ServiceConfig.java:136)
    	at org.apache.dubbo.config.spring.ServiceBean.<init>(ServiceBean.java:56)
    	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:77)
    	at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    	at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:499)
    	at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:480)
    	at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:211)
    	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:87)
    	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1326)
    	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1232)
    	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582)
    	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542)
    	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335)
    	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
    	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333)
    	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208)
    	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:953)
    	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918)
    	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583)
    	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145)
    	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:740)
    	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:415)
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:303)
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1312)
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301)
    	at com.wen3.dubbonacos.DemoProviderApplication.main(DemoProviderApplication.java:15)
    Caused by: java.lang.NoClassDefFoundError: org/jboss/resteasy/client/jaxrs/ClientHttpEngine
    	at java.base/java.lang.Class.forName0(Native Method)
    	at java.base/java.lang.Class.forName(Class.java:467)
    	at org.apache.dubbo.common.extension.ExtensionLoader.loadResource(ExtensionLoader.java:1048)
    	... 45 more
    Caused by: java.lang.ClassNotFoundException: org.jboss.resteasy.client.jaxrs.ClientHttpEngine
    	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
    	at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
    	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:520)
    	... 48 more
    
    	at org.apache.dubbo.common.extension.ExtensionLoader.findException(ExtensionLoader.java:747) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.common.extension.ExtensionLoader.createExtension(ExtensionLoader.java:754) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.common.extension.ExtensionLoader.getExtension(ExtensionLoader.java:548) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.common.extension.ExtensionLoader.getExtension(ExtensionLoader.java:523) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.ServiceConfig.findConfiguredPort(ServiceConfig.java:760) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.ServiceConfig.buildUrl(ServiceConfig.java:543) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.ServiceConfig.doExportUrlsFor1Protocol(ServiceConfig.java:398) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.ServiceConfig.doExportUrls(ServiceConfig.java:386) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.ServiceConfig.doExport(ServiceConfig.java:361) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.ServiceConfig.export(ServiceConfig.java:233) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.deploy.DefaultModuleDeployer.exportServiceInternal(DefaultModuleDeployer.java:338) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.deploy.DefaultModuleDeployer.exportServices(DefaultModuleDeployer.java:310) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.deploy.DefaultModuleDeployer.start(DefaultModuleDeployer.java:142) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.spring.context.DubboDeployApplicationListener.onContextRefreshedEvent(DubboDeployApplicationListener.java:111) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.spring.context.DubboDeployApplicationListener.onApplicationEvent(DubboDeployApplicationListener.java:100) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.spring.context.DubboDeployApplicationListener.onApplicationEvent(DubboDeployApplicationListener.java:45) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:176) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:169) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:143) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:421) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:378) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:938) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:586) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:740) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:415) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1312) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301) ~[spring-boot-2.6.6.jar:2.6.6]
    	at com.wen3.dubbonacos.DemoProviderApplication.main(DemoProviderApplication.java:15) ~[classes/:na]

## 解决403 unknown user错误 ##

把**dubbo**服务注册到**nacos**，如果**nacos**开启了权限认证，那么**springboot**应用的配置文件在写**dubbo**配置项时，需要指定用户名和密码，如果这样指定是无效的

dubbo:
      registry:
        address: nacos://localhost:8848
        username: nacos
        password: nacos

这样在启动时，**dubbo**向**nacos**注册服务会报403 unknown user的错误。

2022-04-05 19:09:28.389  WARN 15740 --- [           main] o.a.dubbo.registry.nacos.NacosRegistry   :  [DUBBO] Failed to unregister url dubbo://192.168.1.4:20880/org.apache.dubbo.metadata.MetadataService?anyhost=true&application=provider1&background=false&connections=1&delay=0&deprecated=false&dubbo=2.0.2&dynamic=true&executes=100&generic=false&group=provider1&interface=org.apache.dubbo.metadata.MetadataService&metadata-type=remote&methods=getMetadataURL,isMetadataService,getExportedURLs,serviceName,version,getSubscribedURLs,getExportedServiceURLs,getMetadataInfo,toSortedStrings,getMetadataInfos,getServiceDefinition&pid=15740&release=3.0.6&revision=3.0.6&service-name-mapping=true&side=provider&timestamp=1649156966499&version=1.0.0 to registry nacos://localhost:8848/org.apache.dubbo.registry.RegistryService?application=provider1&dubbo=2.0.2&group=demo-provider&interface=org.apache.dubbo.registry.RegistryService&pid=15740&qos.enable=false&release=3.0.6&server=localhost on destroy, cause: Failed to unregister dubbo://192.168.1.4:20880/org.apache.dubbo.metadata.MetadataService?anyhost=true&application=provider1&background=false&connections=1&delay=0&deprecated=false&dubbo=2.0.2&dynamic=true&executes=100&generic=false&group=provider1&interface=org.apache.dubbo.metadata.MetadataService&metadata-type=remote&methods=getMetadataURL,isMetadataService,getExportedURLs,serviceName,version,getSubscribedURLs,getExportedServiceURLs,getMetadataInfo,toSortedStrings,getMetadataInfos,getServiceDefinition&pid=15740&release=3.0.6&revision=3.0.6&service-name-mapping=true&side=provider&timestamp=1649156966499&version=1.0.0 to registry localhost:8848, cause: Failed to unregister dubbo://192.168.1.4:20880/org.apache.dubbo.metadata.MetadataService?anyhost=true&application=provider1&background=false&connections=1&delay=0&deprecated=false&dubbo=2.0.2&dynamic=true&executes=100&generic=false&group=provider1&interface=org.apache.dubbo.metadata.MetadataService&metadata-type=remote&methods=getMetadataURL,isMetadataService,getExportedURLs,serviceName,version,getSubscribedURLs,getExportedServiceURLs,getMetadataInfo,toSortedStrings,getMetadataInfos,getServiceDefinition&pid=15740&release=3.0.6&revision=3.0.6&service-name-mapping=true&side=provider&timestamp=1649156966499&version=1.0.0 to nacos nacos://localhost:8848/org.apache.dubbo.registry.RegistryService?application=provider1&dubbo=2.0.2&group=demo-provider&interface=org.apache.dubbo.registry.RegistryService&pid=15740&qos.enable=false&release=3.0.6&server=localhost, cause: failed to req API:/nacos/v1/ns/instance after all servers([localhost:8848]) tried: ErrCode:403, ErrMsg:<html><body><h1>Whitelabel Error Page</h1><p>This application has no explicit mapping for /error, so you are seeing this as a fallback.</p><div id='created'>Tue Apr 05 19:09:28 CST 2022</div><div>There was an unexpected error (type=Forbidden, status=403).</div><div>unknown user!</div></body></html>, dubbo version: 3.0.6, current host: 192.168.1.4
    
    java.lang.IllegalStateException: Failed to unregister dubbo://192.168.1.4:20880/org.apache.dubbo.metadata.MetadataService?anyhost=true&application=provider1&background=false&connections=1&delay=0&deprecated=false&dubbo=2.0.2&dynamic=true&executes=100&generic=false&group=provider1&interface=org.apache.dubbo.metadata.MetadataService&metadata-type=remote&methods=getMetadataURL,isMetadataService,getExportedURLs,serviceName,version,getSubscribedURLs,getExportedServiceURLs,getMetadataInfo,toSortedStrings,getMetadataInfos,getServiceDefinition&pid=15740&release=3.0.6&revision=3.0.6&service-name-mapping=true&side=provider&timestamp=1649156966499&version=1.0.0 to registry localhost:8848, cause: Failed to unregister dubbo://192.168.1.4:20880/org.apache.dubbo.metadata.MetadataService?anyhost=true&application=provider1&background=false&connections=1&delay=0&deprecated=false&dubbo=2.0.2&dynamic=true&executes=100&generic=false&group=provider1&interface=org.apache.dubbo.metadata.MetadataService&metadata-type=remote&methods=getMetadataURL,isMetadataService,getExportedURLs,serviceName,version,getSubscribedURLs,getExportedServiceURLs,getMetadataInfo,toSortedStrings,getMetadataInfos,getServiceDefinition&pid=15740&release=3.0.6&revision=3.0.6&service-name-mapping=true&side=provider&timestamp=1649156966499&version=1.0.0 to nacos nacos://localhost:8848/org.apache.dubbo.registry.RegistryService?application=provider1&dubbo=2.0.2&group=demo-provider&interface=org.apache.dubbo.registry.RegistryService&pid=15740&qos.enable=false&release=3.0.6&server=localhost, cause: failed to req API:/nacos/v1/ns/instance after all servers([localhost:8848]) tried: ErrCode:403, ErrMsg:<html><body><h1>Whitelabel Error Page</h1><p>This application has no explicit mapping for /error, so you are seeing this as a fallback.</p><div id='created'>Tue Apr 05 19:09:28 CST 2022</div><div>There was an unexpected error (type=Forbidden, status=403).</div><div>unknown user!</div></body></html>
    	at org.apache.dubbo.registry.support.FailbackRegistry.unregister(FailbackRegistry.java:266) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.registry.support.AbstractRegistry.destroy(AbstractRegistry.java:496) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.registry.support.FailbackRegistry.destroy(FailbackRegistry.java:407) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.registry.support.RegistryManager.destroyAll(RegistryManager.java:105) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.deploy.DefaultApplicationDeployer.destroyRegistries(DefaultApplicationDeployer.java:1009) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.deploy.DefaultApplicationDeployer.postDestroy(DefaultApplicationDeployer.java:775) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.rpc.model.ApplicationModel.onDestroy(ApplicationModel.java:257) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.rpc.model.ScopeModel.destroy(ScopeModel.java:110) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.rpc.model.ApplicationModel.tryDestroy(ApplicationModel.java:351) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.rpc.model.ModuleModel.onDestroy(ModuleModel.java:124) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.rpc.model.ScopeModel.destroy(ScopeModel.java:110) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.spring.context.DubboDeployApplicationListener.onContextClosedEvent(DubboDeployApplicationListener.java:130) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.spring.context.DubboDeployApplicationListener.onApplicationEvent(DubboDeployApplicationListener.java:102) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.config.spring.context.DubboDeployApplicationListener.onApplicationEvent(DubboDeployApplicationListener.java:45) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:176) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:169) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:143) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:421) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:378) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.doClose(AbstractApplicationContext.java:1058) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.doClose(ServletWebServerApplicationContext.java:172) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.context.support.AbstractApplicationContext.close(AbstractApplicationContext.java:1021) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.boot.builder.ParentContextCloserApplicationListener$ContextCloserListener.onApplicationEvent(ParentContextCloserApplicationListener.java:94) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.builder.ParentContextCloserApplicationListener$ContextCloserListener.onApplicationEvent(ParentContextCloserApplicationListener.java:82) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:176) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:169) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:143) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:421) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:378) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.doClose(AbstractApplicationContext.java:1058) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.close(AbstractApplicationContext.java:1021) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.cloud.bootstrap.BootstrapApplicationListener$CloseContextOnFailureApplicationListener.onApplicationEvent(BootstrapApplicationListener.java:497) ~[spring-cloud-context-3.1.1.jar:3.1.1]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:176) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:169) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:143) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:421) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:378) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.boot.context.event.EventPublishingRunListener.failed(EventPublishingRunListener.java:124) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplicationRunListeners.callFailedListener(SpringApplicationRunListeners.java:96) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplicationRunListeners.lambda$failed$7(SpringApplicationRunListeners.java:87) ~[spring-boot-2.6.6.jar:2.6.6]
    	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511) ~[na:na]
    	at org.springframework.boot.SpringApplicationRunListeners.doWithListeners(SpringApplicationRunListeners.java:120) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplicationRunListeners.failed(SpringApplicationRunListeners.java:86) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplication.handleRunFailure(SpringApplication.java:790) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:313) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1312) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301) ~[spring-boot-2.6.6.jar:2.6.6]
    	at com.wen3.dubbonacos.DemoProviderApplication.main(DemoProviderApplication.java:15) ~[classes/:na]
    Caused by: org.apache.dubbo.rpc.RpcException: Failed to unregister dubbo://192.168.1.4:20880/org.apache.dubbo.metadata.MetadataService?anyhost=true&application=provider1&background=false&connections=1&delay=0&deprecated=false&dubbo=2.0.2&dynamic=true&executes=100&generic=false&group=provider1&interface=org.apache.dubbo.metadata.MetadataService&metadata-type=remote&methods=getMetadataURL,isMetadataService,getExportedURLs,serviceName,version,getSubscribedURLs,getExportedServiceURLs,getMetadataInfo,toSortedStrings,getMetadataInfos,getServiceDefinition&pid=15740&release=3.0.6&revision=3.0.6&service-name-mapping=true&side=provider&timestamp=1649156966499&version=1.0.0 to nacos nacos://localhost:8848/org.apache.dubbo.registry.RegistryService?application=provider1&dubbo=2.0.2&group=demo-provider&interface=org.apache.dubbo.registry.RegistryService&pid=15740&qos.enable=false&release=3.0.6&server=localhost, cause: failed to req API:/nacos/v1/ns/instance after all servers([localhost:8848]) tried: ErrCode:403, ErrMsg:<html><body><h1>Whitelabel Error Page</h1><p>This application has no explicit mapping for /error, so you are seeing this as a fallback.</p><div id='created'>Tue Apr 05 19:09:28 CST 2022</div><div>There was an unexpected error (type=Forbidden, status=403).</div><div>unknown user!</div></body></html>
    	at org.apache.dubbo.registry.nacos.NacosRegistry.doUnregister(NacosRegistry.java:194) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.registry.support.FailbackRegistry.unregister(FailbackRegistry.java:253) ~[dubbo-3.0.6.jar:3.0.6]
    	... 47 common frames omitted
    Caused by: com.alibaba.nacos.api.exception.NacosException: failed to req API:/nacos/v1/ns/instance after all servers([localhost:8848]) tried: ErrCode:403, ErrMsg:<html><body><h1>Whitelabel Error Page</h1><p>This application has no explicit mapping for /error, so you are seeing this as a fallback.</p><div id='created'>Tue Apr 05 19:09:28 CST 2022</div><div>There was an unexpected error (type=Forbidden, status=403).</div><div>unknown user!</div></body></html>
    	at com.alibaba.nacos.client.naming.net.NamingProxy.reqApi(NamingProxy.java:556) ~[nacos-client-1.4.2.jar:na]
    	at com.alibaba.nacos.client.naming.net.NamingProxy.reqApi(NamingProxy.java:498) ~[nacos-client-1.4.2.jar:na]
    	at com.alibaba.nacos.client.naming.net.NamingProxy.reqApi(NamingProxy.java:493) ~[nacos-client-1.4.2.jar:na]
    	at com.alibaba.nacos.client.naming.net.NamingProxy.deregisterService(NamingProxy.java:271) ~[nacos-client-1.4.2.jar:na]
    	at com.alibaba.nacos.client.naming.NacosNamingService.deregisterInstance(NacosNamingService.java:252) ~[nacos-client-1.4.2.jar:na]
    	at com.alibaba.nacos.client.naming.NacosNamingService.deregisterInstance(NacosNamingService.java:238) ~[nacos-client-1.4.2.jar:na]
    	at com.alibaba.nacos.client.naming.NacosNamingService.deregisterInstance(NacosNamingService.java:222) ~[nacos-client-1.4.2.jar:na]
    	at org.apache.dubbo.registry.nacos.NacosNamingServiceWrapper.deregisterInstance(NacosNamingServiceWrapper.java:63) ~[dubbo-3.0.6.jar:3.0.6]
    	at org.apache.dubbo.registry.nacos.NacosRegistry.doUnregister(NacosRegistry.java:189) ~[dubbo-3.0.6.jar:3.0.6]
    	... 48 common frames omitted

翻看了**nacos**源码发现

public void setAddress(String address) {
            this.address = address;
            if (address != null) {
                try {
                    URL url = URL.valueOf(address);
    
                    // Refactor since 2.7.8
                    updatePropertyIfAbsent(this::getUsername, this::setUsername, url.getUsername());
                    updatePropertyIfAbsent(this::getPassword, this::setPassword, url.getPassword());
                    updatePropertyIfAbsent(this::getProtocol, this::setProtocol, url.getProtocol());
                    updatePropertyIfAbsent(this::getPort, this::setPort, url.getPort());
    
                    Map<String, String> params = url.getParameters();
                    if (CollectionUtils.isNotEmptyMap(params)) {
                        params.remove(BACKUP_KEY);
                    }
                    updateParameters(params);
                } catch (Exception ignored) {
                }
            }
        }

在处理**address**时，会处理**username**和**password**，因此需要这样配置

dubbo:
      registry:
        address: nacos://localhost:8848?username=nacos&password=nacos

## 如何把dubbo服务注册到nacos指定的命名空间? ##

翻看**DubboConfigurationProperties**这个类的源码，以及对象成员属性的所有字段，均没有找到任何关于**namespace**的配置项，但在**registry**对象里面有一个**parameters**配置，看起来有点像，试着在这个配置里面追加一个**namespace**，果然成了，正确配置如下

dubbo:
      registry:
        address: nacos://localhost:8848?username=nacos&password=nacos
        parameters:
          namespace: demo-dubbo-nacos

## dubbo消费端 ##

消费端关键的一个注解就是\*\*@DubboReference\*\*，在使用这个注解的时候需要指定版本号和**group**，例如

@DubboReference(version = "demo-1.0.0", group = "demo-provider")

完整代码如下

@RestController
    public class DemoHelloConsumerController {
        
    
        @DubboReference(version = "demo-1.0.0", group = "demo-provider")
        private DemoService demoService;
    
        @GetMapping(path = "/hello-dubbo")
        public String helloDubbo(String name) {
        
            return demoService.helloWorld(name);
        }
    }

## dubbo发布rest服务 ##

只需要修改服务提供者\*\*@DubboService**注解的**protocol\*\*属性  
`@DubboService(protocol = "dubbo,rest")`

### 启动报错 ###

2022-04-09 09:07:39.058 ERROR 10896 --- [           main] o.s.boot.SpringApplication               : Application run failed
    
    java.lang.IllegalStateException: No such extension org.apache.dubbo.rpc.Protocol by name rest, possible causes: 
    (1) rest=org.apache.dubbo.rpc.protocol.rest.RestProtocol:
    java.lang.IllegalStateException: Failed to load extension class (interface: interface org.apache.dubbo.rpc.Protocol, class line: rest=org.apache.dubbo.rpc.protocol.rest.RestProtocol) in jar:file:/G:/repository/org/apache/dubbo/dubbo/3.0.7/dubbo-3.0.7.jar!/META-INF/dubbo/internal/org.apache.dubbo.rpc.Protocol, cause: org/jboss/resteasy/client/jaxrs/ClientHttpEngine
    java.lang.IllegalStateException: Failed to load extension class (interface: interface org.apache.dubbo.rpc.Protocol, class line: rest=org.apache.dubbo.rpc.protocol.rest.RestProtocol) in jar:file:/G:/repository/org/apache/dubbo/dubbo/3.0.7/dubbo-3.0.7.jar!/META-INF/dubbo/internal/org.apache.dubbo.rpc.Protocol, cause: org/jboss/resteasy/client/jaxrs/ClientHttpEngine
    	at org.apache.dubbo.common.extension.ExtensionLoader.loadResource(ExtensionLoader.java:1052)
    	at org.apache.dubbo.common.extension.ExtensionLoader.loadFromClass(ExtensionLoader.java:1019)
    	at org.apache.dubbo.common.extension.ExtensionLoader.lambda$loadDirectory$4(ExtensionLoader.java:1007)
    	at java.base/java.util.LinkedHashMap.forEach(LinkedHashMap.java:721)
    	at java.base/java.util.Collections$UnmodifiableMap.forEach(Collections.java:1553)
    	at org.apache.dubbo.common.extension.ExtensionLoader.loadDirectory(ExtensionLoader.java:1006)
    	at org.apache.dubbo.common.extension.ExtensionLoader.loadDirectory(ExtensionLoader.java:943)
    	at org.apache.dubbo.common.extension.ExtensionLoader.loadExtensionClasses(ExtensionLoader.java:931)
    	at org.apache.dubbo.common.extension.ExtensionLoader.getExtensionClasses(ExtensionLoader.java:913)
    	at org.apache.dubbo.common.extension.ExtensionLoader.getAdaptiveExtensionClass(ExtensionLoader.java:1243)
    	at org.apache.dubbo.common.extension.ExtensionLoader.createAdaptiveExtension(ExtensionLoader.java:1231)
    	at org.apache.dubbo.common.extension.ExtensionLoader.getAdaptiveExtension(ExtensionLoader.java:713)
    	at org.apache.dubbo.config.ServiceConfig.postProcessAfterScopeModelChanged(ServiceConfig.java:154)
    	at org.apache.dubbo.config.AbstractConfig.setScopeModel(AbstractConfig.java:395)
    	at org.apache.dubbo.config.AbstractConfig.<init>(AbstractConfig.java:117)
    	at org.apache.dubbo.config.AbstractMethodConfig.<init>(AbstractMethodConfig.java:103)
    	at org.apache.dubbo.config.AbstractInterfaceConfig.<init>(AbstractInterfaceConfig.java:192)
    	at org.apache.dubbo.config.AbstractServiceConfig.<init>(AbstractServiceConfig.java:132)
    	at org.apache.dubbo.config.ServiceConfigBase.<init>(ServiceConfigBase.java:84)
    	at org.apache.dubbo.config.ServiceConfig.<init>(ServiceConfig.java:136)
    	at org.apache.dubbo.config.spring.ServiceBean.<init>(ServiceBean.java:56)
    	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:77)
    	at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    	at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:499)
    	at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:480)
    	at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:211)
    	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:87)
    	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1326)
    	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1232)
    	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582)
    	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542)
    	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335)
    	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
    	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333)
    	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208)
    	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:953)
    	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918)
    	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583)
    	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145)
    	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:740)
    	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:415)
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:303)
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1312)
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301)
    	at com.wen3.dubbonacos.DemoProviderApplication.main(DemoProviderApplication.java:15)
    Caused by: java.lang.NoClassDefFoundError: org/jboss/resteasy/client/jaxrs/ClientHttpEngine
    	at java.base/java.lang.Class.forName0(Native Method)
    	at java.base/java.lang.Class.forName(Class.java:467)
    	at org.apache.dubbo.common.extension.ExtensionLoader.loadResource(ExtensionLoader.java:1048)
    	... 45 more
    Caused by: java.lang.ClassNotFoundException: org.jboss.resteasy.client.jaxrs.ClientHttpEngine
    	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
    	at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
    	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:520)
    	... 48 more
    
    	at org.apache.dubbo.common.extension.ExtensionLoader.findException(ExtensionLoader.java:747) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.common.extension.ExtensionLoader.createExtension(ExtensionLoader.java:754) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.common.extension.ExtensionLoader.getExtension(ExtensionLoader.java:548) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.common.extension.ExtensionLoader.getExtension(ExtensionLoader.java:523) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.ServiceConfig.findConfiguredPort(ServiceConfig.java:769) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.ServiceConfig.buildUrl(ServiceConfig.java:552) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.ServiceConfig.doExportUrlsFor1Protocol(ServiceConfig.java:408) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.ServiceConfig.doExportUrls(ServiceConfig.java:396) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.ServiceConfig.doExport(ServiceConfig.java:361) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.ServiceConfig.export(ServiceConfig.java:233) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.deploy.DefaultModuleDeployer.exportServiceInternal(DefaultModuleDeployer.java:341) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.deploy.DefaultModuleDeployer.exportServices(DefaultModuleDeployer.java:313) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.deploy.DefaultModuleDeployer.start(DefaultModuleDeployer.java:145) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.spring.context.DubboDeployApplicationListener.onContextRefreshedEvent(DubboDeployApplicationListener.java:111) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.spring.context.DubboDeployApplicationListener.onApplicationEvent(DubboDeployApplicationListener.java:100) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.spring.context.DubboDeployApplicationListener.onApplicationEvent(DubboDeployApplicationListener.java:45) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:176) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:169) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:143) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:421) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:378) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:938) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:586) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:740) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:415) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1312) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301) ~[spring-boot-2.6.6.jar:2.6.6]
    	at com.wen3.dubbonacos.DemoProviderApplication.main(DemoProviderApplication.java:15) ~[classes/:na]

### 解决办法 ###

添加依赖

<dependency>
                <groupId>org.apache.dubbo</groupId>
                <artifactId>dubbo-rpc-rest</artifactId>
                <version>${dubbo.version}</version>
            </dependency>

重启启动就不会提示找不到`org.jboss.resteasy.client.jaxrs.ClientHttpEngine`这个类了

### 再次报错 ###

2022-04-09 09:29:09.393 ERROR 13308 --- [           main] o.s.boot.SpringApplication               : Application run failed
    
    java.lang.RuntimeException: RESTEASY003130: Class is not a root resource.  It, or one of its interfaces must be annotated with @Path: com.wen3.dubbonacos.service.DemoService implements: 
    	at org.jboss.resteasy.core.ResourceMethodRegistry.addResourceFactory(ResourceMethodRegistry.java:185) ~[resteasy-jaxrs-3.14.0.Final.jar:3.14.0.Final]
    	at org.jboss.resteasy.core.ResourceMethodRegistry.addResourceFactory(ResourceMethodRegistry.java:164) ~[resteasy-jaxrs-3.14.0.Final.jar:3.14.0.Final]
    	at org.apache.dubbo.rpc.protocol.rest.BaseRestProtocolServer.deploy(BaseRestProtocolServer.java:53) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.rpc.protocol.rest.RestProtocol.doExport(RestProtocol.java:127) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.rpc.protocol.AbstractProxyProtocol.export(AbstractProxyProtocol.java:89) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.rpc.protocol.ProtocolListenerWrapper.export(ProtocolListenerWrapper.java:66) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.qos.protocol.QosProtocolWrapper.export(QosProtocolWrapper.java:76) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.rpc.cluster.filter.ProtocolFilterWrapper.export(ProtocolFilterWrapper.java:61) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.rpc.protocol.ProtocolSerializationWrapper.export(ProtocolSerializationWrapper.java:47) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.rpc.Protocol$Adaptive.export(Protocol$Adaptive.java) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.registry.integration.RegistryProtocol.lambda$doLocalExport$2(RegistryProtocol.java:294) ~[dubbo-3.0.7.jar:3.0.7]
    	at java.base/java.util.concurrent.ConcurrentHashMap.computeIfAbsent(ConcurrentHashMap.java:1708) ~[na:na]
    	at org.apache.dubbo.registry.integration.RegistryProtocol.doLocalExport(RegistryProtocol.java:292) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.registry.integration.RegistryProtocol.export(RegistryProtocol.java:239) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.rpc.protocol.ProtocolListenerWrapper.export(ProtocolListenerWrapper.java:64) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.qos.protocol.QosProtocolWrapper.export(QosProtocolWrapper.java:74) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.rpc.cluster.filter.ProtocolFilterWrapper.export(ProtocolFilterWrapper.java:58) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.rpc.protocol.ProtocolSerializationWrapper.export(ProtocolSerializationWrapper.java:47) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.rpc.Protocol$Adaptive.export(Protocol$Adaptive.java) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.ServiceConfig.doExportUrl(ServiceConfig.java:641) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.ServiceConfig.exportRemote(ServiceConfig.java:619) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.ServiceConfig.exportUrl(ServiceConfig.java:578) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.ServiceConfig.doExportUrlsFor1Protocol(ServiceConfig.java:410) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.ServiceConfig.doExportUrls(ServiceConfig.java:396) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.ServiceConfig.doExport(ServiceConfig.java:361) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.ServiceConfig.export(ServiceConfig.java:233) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.deploy.DefaultModuleDeployer.exportServiceInternal(DefaultModuleDeployer.java:341) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.deploy.DefaultModuleDeployer.exportServices(DefaultModuleDeployer.java:313) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.deploy.DefaultModuleDeployer.start(DefaultModuleDeployer.java:145) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.spring.context.DubboDeployApplicationListener.onContextRefreshedEvent(DubboDeployApplicationListener.java:111) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.spring.context.DubboDeployApplicationListener.onApplicationEvent(DubboDeployApplicationListener.java:100) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.apache.dubbo.config.spring.context.DubboDeployApplicationListener.onApplicationEvent(DubboDeployApplicationListener.java:45) ~[dubbo-3.0.7.jar:3.0.7]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:176) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:169) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:143) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:421) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:378) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:938) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:586) ~[spring-context-5.3.18.jar:5.3.18]
    	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:740) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:415) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1312) ~[spring-boot-2.6.6.jar:2.6.6]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301) ~[spring-boot-2.6.6.jar:2.6.6]
    	at com.wen3.dubbonacos.DemoProviderApplication.main(DemoProviderApplication.java:15) ~[classes/:na]

### 解决办法 ###

服务实现的接口需要添加**javax.ws.rs**的注解，在定义接口的工程里面添加如下依赖

<dependency>
                <groupId>javax.ws.rs</groupId>
                <artifactId>javax.ws.rs-api</artifactId>
                <version>${javax.ws.rs-api.version}</version>
            </dependency>

接口上添加相关注解

public interface DemoService {
        
    
        @GET
        @Produces
        @Consumes
        @Path("/hello")
        String helloWorld(@QueryParam("name") String name);
    }

## 完善消费者 ##

现在服务提供者向**nacos**注册了三个服务，为什么是3个？

*  nacos做为注册中心，服务提供者向注册中心了注册了一个服务，可以暴露提供者所有的rest接口
 *  引用的**dubbo**框架向**nacos**暴露了一个服务，这个服务同时支持**dubbo**协议和**rest**协议，两个协议的端口不同

所以相当于提供了三个接口，那么消费者可以使用**Feign**组件访问，也可以实现**dubbo**协议访问，我们把这三种访问方式都演示一下，改造后的消费者代码如下

看下**nacos**的服务列表  
![在这里插入图片描述][watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA5aSq56m655y8552b_size_20_color_FFFFFF_t_70_g_se_x_16]

@RestController
    public class DemoHelloConsumerController {
        
    
        @Resource
        private DemoProviderFeign demoProviderFeign;
        @DubboReference(version = "demo-1.0.0", group = "demo-provider", protocol = "dubbo")
        private DemoService demoService;
        @DubboReference(version = "demo-1.0.0", group = "demo-provider", protocol = "rest")
        private DemoService demoServiceRest;
    
        @GetMapping(path = "/hello")
        public String hello(String name) {
        
            return demoProviderFeign.hello(name);
        }
    
        @GetMapping(path = "/hello-dubbo")
        public String helloDubbo(String name) {
        
            return demoService.helloWorld(name);
        }
        
        @GetMapping(path = "/hello-rest")
        public String helloRest(String name) {
        
            return demoServiceRest.helloWorld(name);
        }
    }

启动消费者进行测试

$ curl "http://localhost:8081/hello?name=xxx1"
    xxx1,hello!
    
    $ curl "http://localhost:8081/hello-dubbo?name=xxx2"
    hello xxx2!
    
    $ curl "http://localhost:8081/hello-rest?name=xxx3"
    hello xxx3!

## 总结 ##

本文介绍了一个**SpringBoot**应用，如何向注册中心**nacos**注册**dubbo**服务和**rest**服务，并且在配置和使用过程中遇到的一些常见的问题，也做了分析和解决。

**dubbo**框架既可以发布**dubbo**服务，也能发布**rest**服务，但是对**rest**服务有要求，那就是必须使用**javax.ws.rs**下面的注解。

**dubbo**框架发布的服务更倾向于微服务内部调用，可以提高内部交互的整体性能。**Spring Cloud**注册中心**Eureka**可以无缝替换成**nacos**，并且使用**Feign**调用的场景可以不做任何修改。

[watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBA5aSq56m655y8552b_size_20_color_FFFFFF_t_70_g_se_x_16]: https://img-blog.csdnimg.cn/67066f448a95460a897f677b58526e0b.png?x-oss-process=image/watermark,type_d3F5LXplbmhlaQ,shadow_50,text_Q1NETiBA5aSq56m655y8552b,size_20,color_FFFFFF,t_70,g_se,x_16