报错信息如下：

Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'com.lansoft.isp.api.BsWoCircuitService': Instantiation of bean failed; nested exception is java.lang.ExceptionInInitializerError
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1155)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1099)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:761)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:866)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:542)
    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
    at com.lansoft.isp.start.IspServiceApplication.main(IspServiceApplication.java:16)
Caused by: java.lang.ExceptionInInitializerError
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:142)
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:89)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1147)
    ... 13 more
Caused by: java.lang.IllegalStateException: fail to create adaptive instance: java.lang.IllegalStateException: Can not create adaptive extenstion interface com.alibaba.dubbo.rpc.Protocol, cause: Failed to load extension class(interface: interface com.alibaba.dubbo.common.compiler.Compiler, class line: com.alibaba.dubbo.common.compiler.support.JavassistCompiler) in jar:file:/Users/hanhaoren/Documents/repository/com/alibaba/dubbo/2.8.4/dubbo-2.8.4.jar!/META-INF/dubbo/internal/com.alibaba.dubbo.common.compiler.Compiler, cause: javassist/ClassPath
    at com.alibaba.dubbo.common.extension.ExtensionLoader.getAdaptiveExtension(ExtensionLoader.java:459)
    at com.alibaba.dubbo.config.ServiceConfig.<clinit>(ServiceConfig.java:62)
    ... 20 more
Caused by: java.lang.IllegalStateException: Can not create adaptive extenstion interface com.alibaba.dubbo.rpc.Protocol, cause: Failed to load extension class(interface: interface com.alibaba.dubbo.common.compiler.Compiler, class line: com.alibaba.dubbo.common.compiler.support.JavassistCompiler) in jar:file:/Users/hanhaoren/Documents/repository/com/alibaba/dubbo/2.8.4/dubbo-2.8.4.jar!/META-INF/dubbo/internal/com.alibaba.dubbo.common.compiler.Compiler, cause: javassist/ClassPath
    at com.alibaba.dubbo.common.extension.ExtensionLoader.createAdaptiveExtension(ExtensionLoader.java:723)
    at com.alibaba.dubbo.common.extension.ExtensionLoader.getAdaptiveExtension(ExtensionLoader.java:455)
    ... 21 more
Caused by: java.lang.IllegalStateException: Failed to load extension class(interface: interface com.alibaba.dubbo.common.compiler.Compiler, class line: com.alibaba.dubbo.common.compiler.support.JavassistCompiler) in jar:file:/Users/hanhaoren/Documents/repository/com/alibaba/dubbo/2.8.4/dubbo-2.8.4.jar!/META-INF/dubbo/internal/com.alibaba.dubbo.common.compiler.Compiler, cause: javassist/ClassPath
    at com.alibaba.dubbo.common.extension.ExtensionLoader.loadFile(ExtensionLoader.java:685)
    at com.alibaba.dubbo.common.extension.ExtensionLoader.loadExtensionClasses(ExtensionLoader.java:591)
    at com.alibaba.dubbo.common.extension.ExtensionLoader.getExtensionClasses(ExtensionLoader.java:567)
    at com.alibaba.dubbo.common.extension.ExtensionLoader.getAdaptiveExtensionClass(ExtensionLoader.java:728)
    at com.alibaba.dubbo.common.extension.ExtensionLoader.createAdaptiveExtension(ExtensionLoader.java:721)
    at com.alibaba.dubbo.common.extension.ExtensionLoader.getAdaptiveExtension(ExtensionLoader.java:455)
    at com.alibaba.dubbo.common.extension.ExtensionLoader.createAdaptiveExtensionClass(ExtensionLoader.java:738)
    at com.alibaba.dubbo.common.extension.ExtensionLoader.getAdaptiveExtensionClass(ExtensionLoader.java:732)
    at com.alibaba.dubbo.common.extension.ExtensionLoader.createAdaptiveExtension(ExtensionLoader.java:721)
    ... 22 more
Caused by: java.lang.NoClassDefFoundError: javassist/ClassPath
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:348)
    at com.alibaba.dubbo.common.extension.ExtensionLoader.loadFile(ExtensionLoader.java:627)
    ... 30 more
Caused by: java.lang.ClassNotFoundException: javassist.ClassPath
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 33 more

异常定位：

javassist版本冲突，升级版本

异常处理：

#加入依赖
  <dependency>
      <groupId>org.javassist</groupId>
      <artifactId>javassist</artifactId>
      <version>3.20.0-GA</version>
  </dependency>