我在使用自动配置demo的时候 测试异常

我在测试dubbo异常处理的时候
发现这个异常
```
Caused by: java.lang.reflect.InvocationTargetException: null
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_161]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_161]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_161]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_161]
at org.apache.dubbo.config.spring.beans.factory.annotation.ReferenceAnnotationBeanPostProcessor$ReferenceBeanInvocationHandler.invoke(ReferenceAnnotationBeanPostProcessor.java:158) ~[dubbo-2.7.0.jar:2.7.0]
... 8 common frames omitted
```

谁能帮我看看 要如何解决
具体异常如下

```
Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2019-02-22 10:22:44.020 ERROR 9220 --- [ main] o.s.boot.SpringApplication : Application run failed

java.lang.IllegalStateException: Failed to execute ApplicationRunner
at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:807) [spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]
at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:794) [spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:324) [spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260) [spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248) [spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]
at org.apache.dubbo.spring.boot.demo.consumer.bootstrap.DubboAutoConfigurationConsumerBootstrap.main(DubboAutoConfigurationConsumerBootstrap.java:42) [classes/:na]
Caused by: java.lang.reflect.UndeclaredThrowableException: null
at com.sun.proxy.$Proxy38.sayHello(Unknown Source) ~[na:na]
at org.apache.dubbo.spring.boot.demo.consumer.bootstrap.DubboAutoConfigurationConsumerBootstrap.lambda$runner$0(DubboAutoConfigurationConsumerBootstrap.java:48) [classes/:na]
at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:804) [spring-boot-2.1.2.RELEASE.jar:2.1.2.RELEASE]
... 5 common frames omitted
Caused by: java.lang.reflect.InvocationTargetException: null
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_161]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_161]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_161]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_161]
at org.apache.dubbo.config.spring.beans.factory.annotation.ReferenceAnnotationBeanPostProcessor$ReferenceBeanInvocationHandler.invoke(ReferenceAnnotationBeanPostProcessor.java:158) ~[dubbo-2.7.0.jar:2.7.0]
... 8 common frames omitted
Caused by: java.lang.ArithmeticException: / by zero
at org.apache.dubbo.spring.boot.demo.provider.service.DefaultDemoService.sayHello(DefaultDemoService.java:39) ~[na:na]
at org.apache.dubbo.common.bytecode.Wrapper1.invokeMethod(Wrapper1.java) ~[na:na]
at org.apache.dubbo.rpc.proxy.javassist.JavassistProxyFactory$1.doInvoke(JavassistProxyFactory.java:47) ~[dubbo-2.7.0.jar:2.7.0]
at org.apache.dubbo.rpc.proxy.AbstractProxyInvoker.invoke(AbstractProxyInvoker.java:86) ~[dubbo-2.7.0.jar:2.7.0]
at org.apache.dubbo.config.invoker.DelegateProviderMetaDataInvoker.invoke(DelegateProviderMetaDataInvoker.java:56) ~[dubbo-2.7.0.jar:2.7.0]
at org.apache.dubbo.rpc.filter.ExceptionFilter.invoke(ExceptionFilter.java:63) ~[dubbo-2.7.0.jar:2.7.0]
at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:73) ~[dubbo-2.7.0.jar:2.7.0]
at org.apache.dubbo.monitor.support.MonitorFilter.invoke(MonitorFilter.java:88) ~[dubbo-2.7.0.jar:2.7.0]
at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:73) ~[dubbo-2.7.0.jar:2.7.0]
at org.apache.dubbo.rpc.filter.TimeoutFilter.invoke(TimeoutFilter.java:42) ~[dubbo-2.7.0.jar:2.7.0]
at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:73) ~[dubbo-2.7.0.jar:2.7.0]
at org.apache.dubbo.rpc.protocol.dubbo.filter.TraceFilter.invoke(TraceFilter.java:79) ~[dubbo-2.7.0.jar:2.7.0]
at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:73) ~[dubbo-2.7.0.jar:2.7.0]
at org.apache.dubbo.rpc.filter.ContextFilter.invoke(ContextFilter.java:78) ~[dubbo-2.7.0.jar:2.7.0]
at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:73) ~[dubbo-2.7.0.jar:2.7.0]
at org.apache.dubbo.rpc.filter.GenericFilter.invoke(GenericFilter.java:138) ~[dubbo-2.7.0.jar:2.7.0]
at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:73) ~[dubbo-2.7.0.jar:2.7.0]
at org.apache.dubbo.rpc.filter.ClassLoaderFilter.invoke(ClassLoaderFilter.java:38) ~[dubbo-2.7.0.jar:2.7.0]
at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:73) ~[dubbo-2.7.0.jar:2.7.0]
at org.apache.dubbo.rpc.filter.EchoFilter.invoke(EchoFilter.java:39) ~[dubbo-2.7.0.jar:2.7.0]
at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:73) ~[dubbo-2.7.0.jar:2.7.0]
at org.apache.dubbo.rpc.protocol.dubbo.DubboProtocol$1.reply(DubboProtocol.java:108) ~[dubbo-2.7.0.jar:2.7.0]
at org.apache.dubbo.remoting.exchange.support.header.HeaderExchangeHandler.handleRequest(HeaderExchangeHandler.java:103) ~[dubbo-2.7.0.jar:2.7.0]
at org.apache.dubbo.remoting.exchange.support.header.HeaderExchangeHandler.received(HeaderExchangeHandler.java:200) ~[dubbo-2.7.0.jar:2.7.0]
at org.apache.dubbo.remoting.transport.DecodeHandler.received(DecodeHandler.java:51) ~[dubbo-2.7.0.jar:2.7.0]
at org.apache.dubbo.remoting.transport.dispatcher.ChannelEventRunnable.run(ChannelEventRunnable.java:57) ~[dubbo-2.7.0.jar:2.7.0]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) ~[na:1.8.0_161]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) ~[na:1.8.0_161]
at java.lang.Thread.run(Thread.java:748) ~[na:1.8.0_161]

```