在啟動微服務專案時，每個服務都啟動不起來，報如下一樣的錯

org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:
 
157) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543) ~[spring-context-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:
 
142) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775) [spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) [spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:
 
316) [spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260) [spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248) [spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at com.leyou.LyApiGateway.main(LyApiGateway.java:14) [classes/:na]
Caused by: org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat
    at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:125) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.<init>(TomcatWebServer.java:86) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:427) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:180) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:181) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:154) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    ... 8 common frames omitted
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'webMvcMetricsFilter' defined in class path resource [org/springframework/boot/actuate/autoconfigure/metrics/web/servlet/WebMvcMetricsAutoConfiguration.class]: Unsatisfied dependency expressed through method 'webMvcMetricsFilter' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'simpleMeterRegistry' defined in class path resource [org/springframework/boot/actuate/autoconfigure/metrics/export/simple/SimpleMetricsExportAutoConfiguration.class]: Initialization of bean failed; nested exception is java.lang.NoClassDefFoundError: com/google/common/collect/Lists
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:769) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:509) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1321) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1160) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:204) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.boot.web.servlet.ServletContextInitializerBeans.getOrderedBeansOfType(ServletContextInitializerBeans.java:235) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.boot.web.servlet.ServletContextInitializerBeans.getOrderedBeansOfType(ServletContextInitializerBeans.java:226) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.boot.web.servlet.ServletContextInitializerBeans.addServletContextInitializerBeans(ServletContextInitializerBeans.java:101) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.boot.web.servlet.ServletContextInitializerBeans.<init>(ServletContextInitializerBeans.java:88) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.getServletContextInitializerBeans(ServletWebServerApplicationContext.java:261) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.selfInitialize(ServletWebServerApplicationContext.java:234) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.boot.web.embedded.tomcat.TomcatStarter.onStartup(TomcatStarter.java:54) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5139) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1377) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1367) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_77]
    at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134) ~[na:1.8.0_77]
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:902) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:831) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1377) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1367) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_77]
    at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134) ~[na:1.8.0_77]
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:902) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.core.StandardService.startInternal(StandardService.java:423) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:928) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.apache.catalina.startup.Tomcat.start(Tomcat.java:455) ~[tomcat-embed-core-9.0.17.jar:9.0.17]
    at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:106) ~[spring-boot-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    ... 13 common frames omitted
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'simpleMeterRegistry' defined in class path resource [org/springframework/boot/actuate/autoconfigure/metrics/export/simple/SimpleMetricsExportAutoConfiguration.class]: Initialization of bean failed; nested exception is java.lang.NoClassDefFoundError: com/google/common/collect/Lists
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:601) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:277) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1247) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1167) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:857) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:760) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    ... 53 common frames omitted
Caused by: java.lang.NoClassDefFoundError: com/google/common/collect/Lists
    at com.netflix.config.PropertyWrapper.<init>(PropertyWrapper.java:41) ~[archaius-core-0.7.6.jar:0.7.6]
    at com.netflix.hystrix.strategy.properties.archaius.HystrixDynamicPropertiesArchaius$ArchaiusDynamicProperty.<init>(HystrixDynamicPropertiesArchaius.java:62) ~[hystrix-core-1.5.12.jar:1.5.12]
    at com.netflix.hystrix.strategy.properties.archaius.HystrixDynamicPropertiesArchaius$StringDynamicProperty.<init>(HystrixDynamicPropertiesArchaius.java:73) ~[hystrix-core-1.5.12.jar:1.5.12]
    at com.netflix.hystrix.strategy.properties.archaius.HystrixDynamicPropertiesArchaius.getString(HystrixDynamicPropertiesArchaius.java:34) ~[hystrix-core-1.5.12.jar:1.5.12]
    at com.netflix.hystrix.strategy.HystrixPlugins.getPluginImplementationViaProperties(HystrixPlugins.java:344) ~[hystrix-core-1.5.12.jar:1.5.12]
    at com.netflix.hystrix.strategy.HystrixPlugins.getPluginImplementation(HystrixPlugins.java:334) ~[hystrix-core-1.5.12.jar:1.5.12]
    at com.netflix.hystrix.strategy.HystrixPlugins.getEventNotifier(HystrixPlugins.java:129) ~[hystrix-core-1.5.12.jar:1.5.12]
    at io.micrometer.core.instrument.binder.hystrix.HystrixMetricsBinder.bindTo(HystrixMetricsBinder.java:36) ~[micrometer-core-1.1.4.jar:1.1.4]
    at org.springframework.boot.actuate.autoconfigure.metrics.MeterRegistryConfigurer.lambda$addBinders$1(MeterRegistryConfigurer.java:82) ~[spring-boot-actuator-autoconfigure-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:184) ~[na:1.8.0_77]
    at java.util.ArrayList.forEach(ArrayList.java:1249) ~[na:1.8.0_77]
    at java.util.stream.SortedOps$RefSortingSink.end(SortedOps.java:390) ~[na:1.8.0_77]
    at java.util.stream.Sink$ChainedReference.end(Sink.java:258) ~[na:1.8.0_77]
    at java.util.stream.Sink$ChainedReference.end(Sink.java:258) ~[na:1.8.0_77]
    at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:482) ~[na:1.8.0_77]
    at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471) ~[na:1.8.0_77]
    at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151) ~[na:1.8.0_77]
    at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174) ~[na:1.8.0_77]
    at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[na:1.8.0_77]
    at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:418) ~[na:1.8.0_77]
    at org.springframework.boot.actuate.autoconfigure.metrics.MeterRegistryConfigurer.addBinders(MeterRegistryConfigurer.java:82) ~[spring-boot-actuator-autoconfigure-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.boot.actuate.autoconfigure.metrics.MeterRegistryConfigurer.configure(MeterRegistryConfigurer.java:62) ~[spring-boot-actuator-autoconfigure-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.boot.actuate.autoconfigure.metrics.MeterRegistryPostProcessor.postProcessAfterInitialization(MeterRegistryPostProcessor.java:61) ~[spring-boot-actuator-autoconfigure-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsAfterInitialization(AbstractAutowireCapableBeanFactory.java:429) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1782) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593) ~[spring-beans-5.1.6.RELEASE.jar:5.1.6.RELEASE]
    ... 63 common frames omitted
Caused by: java.lang.ClassNotFoundException: com.google.common.collect.Lists
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_77]
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_77]
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331) ~[na:1.8.0_77]
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_77]
    ... 89 common frames omitted

這麼多錯，我先從第一個看起

說是內建tomcat啟動不起來，網上搜了很多文章都不對

第二，三個錯誤，都是建立bean例項失敗

我就想到了springboot自動裝配的問題，檢視啟動類上是有@springbootApplication類的，這個註解裡面包含了@EnableAutoConfiguration這個註解呀

第五，六個錯誤

類沒找到異常？難道是jar包缺失的問題？

於是就在網上搜了這個異常，發現了一個熟悉的jar包，需要載入這個jar包，我記得搭建springcloud專案的時候，為了解決依賴衝突，於是就將guava排除了

解決： 在每個需要啟動類的微服務中加了這個依賴，服務才正常啟動。注意，我可以在父類中加，但是maven工程匯入太慢了，要等很久，所以我才逐個加大。自動的還不如手動的快。