spring创建bean异常
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'requestMappingHandlerMapping' defined in class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]: Invocation of init method failed; nested exception is java.lang.IllegalStateException: Ambiguous mapping. Cannot map 'sysUserController' method com.benben.percms.system.controller.SysUserController#addOne(SysUser) to {POST /addOne}: There is already 'sysRoleController' bean method com.benben.percms.system.controller.SysRoleController#addOne(SysRole) mapped. at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1803) ~[spring-beans-5.2.1.RELEASE.jar:5.2.1.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:595) ~[spring-beans-5.2.1.RELEASE.jar:5.2.1.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.1.RELEASE.jar:5.2.1.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.1.RELEASE.jar:5.2.1.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.2.1.RELEASE.jar:5.2.1.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.1.RELEASE.jar:5.2.1.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.1.RELEASE.jar:5.2.1.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:879) ~[spring-beans-5.2.1.RELEASE.jar:5.2.1.RELEASE] at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:878) ~[spring-context-5.2.1.RELEASE.jar:5.2.1.RELEASE] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550) ~[spring-context-5.2.1.RELEASE.jar:5.2.1.RELEASE] at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141) ~[spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747) [spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE] at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) [spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) [spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215) [spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE] at com.benben.percms.PerCmsApplication.main(PerCmsApplication.java:12) [classes/:na] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_144] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_144] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_144] at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_144] at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-2.2.1.RELEASE.jar:2.2.1.RELEASE] Caused by: java.lang.IllegalStateException: Ambiguous mapping. Cannot map 'sysUserController' method com.benben.percms.system.controller.SysUserController#addOne(SysUser) to {POST /addOne}: There is already 'sysRoleController' bean method com.benben.percms.system.controller.SysRoleController#addOne(SysRole) mapped. at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping$MappingRegistry.validateMethodMapping(AbstractHandlerMethodMapping.java:633) ~[spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE] at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping$MappingRegistry.register(AbstractHandlerMethodMapping.java:600) ~[spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE] at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.registerHandlerMethod(AbstractHandlerMethodMapping.java:318) ~[spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE] at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping.registerHandlerMethod(RequestMappingHandlerMapping.java:350) ~[spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE] at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping.registerHandlerMethod(RequestMappingHandlerMapping.java:67) ~[spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE] at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.lambda$detectHandlerMethods$1(AbstractHandlerMethodMapping.java:288) ~[spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE] at java.util.LinkedHashMap.forEach(LinkedHashMap.java:684) ~[na:1.8.0_144] at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.detectHandlerMethods(AbstractHandlerMethodMapping.java:286) ~[spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE] at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.processCandidateBean(AbstractHandlerMethodMapping.java:258) ~[spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE] at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.initHandlerMethods(AbstractHandlerMethodMapping.java:217) ~[spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE] at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.afterPropertiesSet(AbstractHandlerMethodMapping.java:205) ~[spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE] at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping.afterPropertiesSet(RequestMappingHandlerMapping.java:171) ~[spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1862) ~[spring-beans-5.2.1.RELEASE.jar:5.2.1.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1799) ~[spring-beans-5.2.1.RELEASE.jar:5.2.1.RELEASE] ... 21 common frames omitted
这个异常很简单，贴出来就是帮助一下新童鞋。
一般出现这个异常的时候是在controller出现的多一些，我就拿controller说吧。
我第一次看到这个异常的时候也很蒙蔽，我的代码明明没有错，为啥就是不能创建bean呢？
原来我是创建了两个名字不同但内容一样的controller 比如这样:
还有这个
根据上边的报错内容你一定会吧其中的某一个方法改名或者删掉，发现另一个方法又报错了，因为我这里是两组方法一样。
其实他不是因为spring有问题的，原因很简单，我们一个url链接应该对应一个接口 ，但是上边的代码却对应了两个，所以web不知道这个url应该到底对应谁，所以才会报错。
于是有两种解决方法:
1. 把两个类中的url链接都改成不一样的，但是应用大了之后免不了有很多功能一样的方法 就比如添加 一般我喜欢命名为add ， 再改能改几个呀，要是人家有100个类都有这么个方法，你难道要起100个名字？
2.于是我们可以在类上边打个@RequestMapping(),给这个类定义一个类访问路径就好了，能少掉两个头发
