java.lang.NoClassDefFoundError: org/apache/curator/RetryPolicy

    at com.alibaba.dubbo.remoting.zookeeper.curator.CuratorZookeeperTransporter.connect(CuratorZookeeperTransporter.java:27)

    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:38)

    at com.alibaba.dubbo.registry.support.AbstractRegistryFactory.getRegistry(AbstractRegistryFactory.java:96)

    at com.alibaba.dubbo.registry.RegistryFactory$Adaptive.getRegistry(RegistryFactory$Adaptive.java)

    at com.alibaba.dubbo.registry.integration.RegistryProtocol.getRegistry(RegistryProtocol.java:202)

    at com.alibaba.dubbo.registry.integration.RegistryProtocol.export(RegistryProtocol.java:136)

    .....

    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:1149)

    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)

    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)

    ... 37 more

　　　　<dependency>

            <groupId>org.apache.curator</groupId>

            <artifactId>curator-framework</artifactId>

            <version>2.8.0</version>

        </dependency>

        <dependency>

            <groupId>org.apache.curator</groupId>

            <artifactId>curator-recipes</artifactId>

            <version>2.8.0</version>

        </dependency>