Spring Boot2.1.7启动zipkin-server报错：Error creating bean with name 'armeriaServer' defined in class path
修改项目，更新组件版本时，引入了最新版本2.12.9的zipkin-server和zipkin-autoconfigure-ui时，服务启动报错：
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'armeriaServer' defined in class path resource [com/linecorp/armeria/spring/ArmeriaAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.linecorp.armeria.server.Server]: Factory method 'armeriaServer' threw exception; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:627) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE] at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:607) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1321) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1160) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:845) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE] at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:877) ~[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549) ~[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE] at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141) ~[spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:743) [spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE] at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:390) [spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:312) [spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1214) [spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1203) [spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE] at com.example.demo1.DemoZipkinApplication.main(DemoZipkinApplication.java:15) [classes/:na] Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.linecorp.armeria.server.Server]: Factory method 'armeriaServer' threw exception; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE] at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:622) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE] ... 19 common frames omitted Caused by: java.lang.NullPointerException: null at zipkin2.autoconfigure.ui.ZipkinUiAutoConfiguration.lambda$uiServerConfigurator$0(ZipkinUiAutoConfiguration.java:179) ~[zipkin-autoconfigure-ui-2.12.9.jar:na] at com.linecorp.armeria.spring.ArmeriaAutoConfiguration.lambda$armeriaServer$0(ArmeriaAutoConfiguration.java:111) ~[armeria-spring-boot-autoconfigure-0.83.0.jar:na] at java.util.ArrayList.forEach(ArrayList.java:1257) ~[na:1.8.0_191] at com.linecorp.armeria.spring.ArmeriaAutoConfiguration.lambda$armeriaServer$1(ArmeriaAutoConfiguration.java:110) ~[armeria-spring-boot-autoconfigure-0.83.0.jar:na] at java.util.Optional.ifPresent(Optional.java:159) ~[na:1.8.0_191] at com.linecorp.armeria.spring.ArmeriaAutoConfiguration.armeriaServer(ArmeriaAutoConfiguration.java:109) ~[armeria-spring-boot-autoconfigure-0.83.0.jar:na] at com.linecorp.armeria.spring.ArmeriaAutoConfiguration$$EnhancerBySpringCGLIB$$cec31257.CGLIB$armeriaServer$0(<generated>) ~[armeria-spring-boot-autoconfigure-0.83.0.jar:na] at com.linecorp.armeria.spring.ArmeriaAutoConfiguration$$EnhancerBySpringCGLIB$$cec31257$$FastClassBySpringCGLIB$$accc49b7.invoke(<generated>) ~[armeria-spring-boot-autoconfigure-0.83.0.jar:na] at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244) ~[spring-core-5.1.9.RELEASE.jar:5.1.9.RELEASE] at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:363) ~[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE] at com.linecorp.armeria.spring.ArmeriaAutoConfiguration$$EnhancerBySpringCGLIB$$cec31257.armeriaServer(<generated>) ~[armeria-spring-boot-autoconfigure-0.83.0.jar:na] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_191] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_191] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_191] at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_191] at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE] ... 20 common frames omitted
错误原因：
Zipkin最新2.12.9版从2.12.6开始有个较大的更新，迁移使用了Armeria HTTP引擎。存在版本冲突。
解决方法：
将版本降低到2.12.3就可以正常启动了。
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