最近一直在写开源小项目，遇到了大大小小的BUG，小BUG也就算了，大BUG（指的是花费很多时间才DEBUG的）需要写一个博客记录一下，避免以后再犯这种错误。
切记，不要因为某些错误，乱导jar包！
报错截图如下：
关键的错误信息：
core.dao.BaseDao.processQuery(BaseDao.java:610)
message Handler processing failed; nested exception is java.lang.NoSuchMethodError: org.apache.commons.beanutils.MethodUtils.getAccessibleMethod
意思是：没有指定的方法，能让我调用
或者说，你给了我太多的可调用方法，我没法选！
解决过程：
1.看到 core.dao.BaseDao.processQuery(BaseDao.java:610) 报错 打开这个java文件
2.看到org.apache.commons.beanutils.MethodUtils.getAccessibleMethod，可以推测出，org.apache.commons.beanutils这个jar包有问题！在java类中找到出错的头文件
3.打开项目lib目录，寻找是否缺少 / 重复 jar文件
4.删除其中一个，推荐删除老版本
因为老版本和新版本绝大多数的方法是重复的，如果两个包同时存在，系统不知道该用哪个包的方法，所以报错。
5.重新编译运行项目 ，成功解决
最后附上报错完整信息：
HTTP Status 500 - Handler processing failed; nested exception is java.lang.NoSuchMethodError: org.apache.commons.beanutils.MethodUtils.getAccessibleMethod(Ljava/lang/Class;Ljava/lang/reflect/Method;)Ljava/lang/reflect/Method;
type Exception report
message Handler processing failed; nested exception is java.lang.NoSuchMethodError: org.apache.commons.beanutils.MethodUtils.getAccessibleMethod(Ljava/lang/Class;Ljava/lang/reflect/Method;)Ljava/lang/reflect/Method;
description The server encountered an internal error that prevented it from fulfilling this request.
exception
org.springframework.web.util.NestedServletException: Handler processing failed; nested exception is java.lang.NoSuchMethodError: org.apache.commons.beanutils.MethodUtils.getAccessibleMethod(Ljava/lang/Class;Ljava/lang/reflect/Method;)Ljava/lang/reflect/Method;
org.springframework.web.servlet.DispatcherServlet.triggerAfterCompletionWithError(DispatcherServlet.java:1259)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:945)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:953)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:844)
javax.servlet.http.HttpServlet.service(HttpServlet.java:618)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:829)
javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
core.web.LoginFilter.doFilter(LoginFilter.java:51)
root cause
java.lang.NoSuchMethodError: org.apache.commons.beanutils.MethodUtils.getAccessibleMethod(Ljava/lang/Class;Ljava/lang/reflect/Method;)Ljava/lang/reflect/Method;
core.util.BeanUtils.describeAvailableParameter(BeanUtils.java:57)
core.dao.BaseDao.processQuery(BaseDao.java:610)
core.dao.BaseDao.doPaginationQuery(BaseDao.java:441)
core.dao.BaseDao.doPaginationQuery(BaseDao.java:432)
core.service.BaseService.doPaginationQuery(BaseService.java:183)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:483)
org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:96)
org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:260)
org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:94)
org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
com.sun.proxy.$Proxy101.doPaginationQuery(Unknown Source)
com.forestry.controller.sys.TelController.getHouseList(TelController.java:176)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:483)
org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:215)
org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:745)
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:686)
org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:925)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:953)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:844)
javax.servlet.http.HttpServlet.service(HttpServlet.java:618)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:829)
javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
core.web.LoginFilter.doFilter(LoginFilter.java:51)
note The full stack trace of the root cause is available in the Apache Tomcat/8.0.9 logs.
Apache Tomcat/8.0.9