java.lang.NoClassDefFoundError: com/netflix/hystrix/contrib/javanica/aop/aspectj/HystrixCommandAspec

最近在做项目改造，用spring cloud做服务拆分，这两天在跑的过程中出现一个问题，老报如下错误：

java.lang.NoClassDefFoundError: com/netflix/hystrix/contrib/javanica/aop/aspectj/HystrixCommandAspectat java.lang.Class.getDeclaredMethods0(Native Method)at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)at java.lang.Class.getDeclaredMethods(Class.java:1975)at org.springframework.util.ReflectionUtils.getDeclaredMethods(ReflectionUtils.java:613)at org.springframework.util.ReflectionUtils.doWithMethods(ReflectionUtils.java:524)at org.springframework.util.ReflectionUtils.doWithMethods(ReflectionUtils.java:510)at org.springframework.util.ReflectionUtils.getUniqueDeclaredMethods(ReflectionUtils.java:570)at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.getTypeForFactoryMethod(AbstractAutowireCapableBeanFactory.java:697)at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.determineTargetType(AbstractAutowireCapableBeanFactory.java:640)at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.predictBeanType(AbstractAutowireCapableBeanFactory.java:609)at org.springframework.beans.factory.support.AbstractBeanFactory.isFactoryBean(AbstractBeanFactory.java:1484)at org.springframework.beans.factory.support.DefaultListableBeanFactory.doGetBeanNamesForType(DefaultListableBeanFactory.java:425)at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanNamesForType(DefaultListableBeanFactory.java:395)at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeansOfType(DefaultListableBeanFactory.java:515)at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeansOfType(DefaultListableBeanFactory.java:508)at org.springframework.context.support.AbstractApplicationContext.getBeansOfType(AbstractApplicationContext.java:1188)at org.springframework.boot.SpringApplication.getExitCodeFromMappedException(SpringApplication.java:818)at org.springframework.boot.SpringApplication.getExitCodeFromException(SpringApplication.java:804)at org.springframework.boot.SpringApplication.handleExitCode(SpringApplication.java:790)at org.springframework.boot.SpringApplication.handleRunFailure(SpringApplication.java:744)at org.springframework.boot.SpringApplication.run(SpringApplication.java:314)at org.springframework.boot.test.context.SpringBootContextLoader.loadContext(SpringBootContextLoader.java:120)at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:98)at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:116)at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:83)at org.springframework.test.context.web.ServletTestExecutionListener.setUpRequestContextIfNecessary(ServletTestExecutionListener.java:189)at org.springframework.test.context.web.ServletTestExecutionListener.prepareTestInstance(ServletTestExecutionListener.java:131)at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:230)at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:228)at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:287)at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:289)at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:247)at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94)at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)at org.junit.runners.ParentRunner.run(ParentRunner.java:363)at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191)at org.junit.runner.JUnitCore.run(JUnitCore.java:137)at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:51)at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)Caused by: java.lang.ClassNotFoundException: com.netflix.hystrix.contrib.javanica.aop.aspectj.HystrixCommandAspectat java.net.URLClassLoader.findClass(URLClassLoader.java:381)at java.lang.ClassLoader.loadClass(ClassLoader.java:424)at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)at java.lang.ClassLoader.loadClass(ClassLoader.java:357)... 48 more

百思不得姐，百度半天查不出所以然来，果断上stackoverflow搜了下，一下找到问题，链接如下：

https://stackoverflow.com/questions/46407098/is-enablefeignclients-enablecircuitbreaker-conflict

意思是

@SpringCloudApplication注解相当于
@SpringBootApplication@EnableDiscoveryClient@EnableCircuitBreaker
这三个，其中
@EnableCircuitBreaker
需要依赖
spring-cloud-starter-hystrix
果断在pom里面加入依赖：
<dependency>    <groupId>org.springframework.cloud</groupId>    <artifactId>spring-cloud-starter-hystrix</artifactId></dependency>
问题得到解决，不过还需要看看源代码，上班了稍后补充一下。