java.lang.NoClassDefFoundError: org/apache/curator/RetryPolicy
at com.alibaba.dubbo.remoting.zookeeper.curator.CuratorZookeeperTransporter.connect(CuratorZookeeperTransporter.java:26)
at com.alibaba.dubbo.remoting.zookeeper.ZookeeperTransporter$Adaptive.connect(ZookeeperTransporter$Adaptive.java)
at com.alibaba.dubbo.registry.zookeeper.ZookeeperRegistry.<init>(ZookeeperRegistry.java:69)
at com.alibaba.dubbo.registry.zookeeper.ZookeeperRegistryFactory.createRegistry(ZookeeperRegistryFactory.java:37)
at com.alibaba.dubbo.registry.support.AbstractRegistryFactory.getRegistry(AbstractRegistryFactory.java:95)
at com.alibaba.dubbo.registry.RegistryFactory$Adaptive.getRegistry(RegistryFactory$Adaptive.java)
at com.alibaba.dubbo.registry.integration.RegistryProtocol.getRegistry(RegistryProtocol.java:200)
at com.alibaba.dubbo.registry.integration.RegistryProtocol.export(RegistryProtocol.java:134)
at com.alibaba.dubbo.rpc.protocol.ProtocolListenerWrapper.export(ProtocolListenerWrapper.java:54)
at com.alibaba.dubbo.qos.protocol.QosProtocolWrapper.export(QosProtocolWrapper.java:54)
at com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper.export(ProtocolFilterWrapper.java:91)
at com.alibaba.dubbo.rpc.Protocol$Adaptive.export(Protocol$Adaptive.java)
at com.alibaba.dubbo.config.ServiceConfig.doExportUrlsFor1Protocol(ServiceConfig.java:505)
at com.alibaba.dubbo.config.ServiceConfig.doExportUrls(ServiceConfig.java:357)
at com.alibaba.dubbo.config.ServiceConfig.doExport(ServiceConfig.java:316)
at com.alibaba.dubbo.config.ServiceConfig.export(ServiceConfig.java:215)
at com.alibaba.dubbo.config.spring.ServiceBean.onApplicationEvent(ServiceBean.java:121)
at com.alibaba.dubbo.config.spring.ServiceBean.onApplicationEvent(ServiceBean.java:50)
at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:167)
at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:393)
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:347)
at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:883)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:546)
at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:443)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:325)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:107)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4939)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5434)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.ClassNotFoundException: org.apache.curator.RetryPolicy
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1702)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1547)
... 36 morejava.lang.NoClassDefFoundError: org/apache/curator/RetryPolicy
at com.alibaba.dubbo.remoting.zookeeper.curator.CuratorZookeeperTransporter.connect(CuratorZookeeperTransporter.java:26)
at com.alibaba.dubbo.remoting.zookeeper.ZookeeperTransporter$Adaptive.connect(ZookeeperTransporter$Adaptive.java)
at com.alibaba.dubbo.registry.zookeeper.ZookeeperRegistry.<init>(ZookeeperRegistry.java:69)
at com.alibaba.dubbo.registry.zookeeper.ZookeeperRegistryFactory.createRegistry(ZookeeperRegistryFactory.java:37)
at com.alibaba.dubbo.registry.support.AbstractRegistryFactory.getRegistry(AbstractRegistryFactory.java:95)
at com.alibaba.dubbo.registry.RegistryFactory$Adaptive.getRegistry(RegistryFactory$Adaptive.java)
at com.alibaba.dubbo.registry.integration.RegistryProtocol.getRegistry(RegistryProtocol.java:200)
at com.alibaba.dubbo.registry.integration.RegistryProtocol.export(RegistryProtocol.java:134)
at com.alibaba.dubbo.rpc.protocol.ProtocolListenerWrapper.export(ProtocolListenerWrapper.java:54)
at com.alibaba.dubbo.qos.protocol.QosProtocolWrapper.export(QosProtocolWrapper.java:54)
at com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper.export(ProtocolFilterWrapper.java:91)
at com.alibaba.dubbo.rpc.Protocol$Adaptive.export(Protocol$Adaptive.java)
at com.alibaba.dubbo.config.ServiceConfig.doExportUrlsFor1Protocol(ServiceConfig.java:505)
at com.alibaba.dubbo.config.ServiceConfig.doExportUrls(ServiceConfig.java:357)
at com.alibaba.dubbo.config.ServiceConfig.doExport(ServiceConfig.java:316)
at com.alibaba.dubbo.config.ServiceConfig.export(ServiceConfig.java:215)
at com.alibaba.dubbo.config.spring.ServiceBean.onApplicationEvent(ServiceBean.java:121)
at com.alibaba.dubbo.config.spring.ServiceBean.onApplicationEvent(ServiceBean.java:50)
at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:167)
at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:393)
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:347)
at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:883)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:546)
at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:443)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:325)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:107)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4939)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5434)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.ClassNotFoundException: org.apache.curator.RetryPolicy
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1702)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1547)
... 36 more
这些是之前错的代码，对于这种问题呢？有这么几种问题。
第一种问题：
本人遇到的是由于jar包的问题，因为本人用的jar包是
<groupId>com.alibaba</groupId> <artifactId>dubbo</artifactId> <version>2.6.1</version>
最新的一个jar包，一般最新的都会多多少少有一些未知名错误，今天着实被坑了一把，改来改去，最后终于找到是这家伙搞的鬼，当我们用之前的2.5.9这个版本的包就不会在报错了。
第二种问题：
我们导这个包的时候千万不要手欠，一定要记得
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>4.3.14.RELEASE</version>
</dependency>
要记得加webmvc别直接弄一个spring-web着急了就会导致一个错误。
各位大神们 踩坑之前一定要做好准备，不然的话到时候就不知所措了。。。。
来源：CSDN
作者：ahb6063088
链接：https://blog.csdn.net/ahb6063088/article/details/81515796