重载请求映射-Java

我正在使用带有Spring Security的Java，我想重载我的RequestMapping，但我发现了错误：

@RequestMapping("/")
    public ModelAndView index(OAuth2AuthenticationToken authentication) {
        Map<String, Object> userInfo = authentication.getPrincipal().getAttributes();
        String nome = (String) userInfo.get("name");
        System.out.println(nome);
        ModelAndView mv = new ModelAndView("index");
        mv.addObject("nome", nome);
        System.out.println("Index"); 
        return mv;
    }
    @RequestMapping("/")
    public ModelAndView index() {
        String nome = "Blaa";
        System.out.println(nome);
        ModelAndView mv = new ModelAndView("index");
        mv.addObject("nome", nome);
        System.out.println("Index"); 
        return mv;
    }

我该怎么做

我的愿望是，如果用户使用Oauth2登录，那么我通过参数获得他的名字。如果他不是，那么我设置一个默认名称

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'requestMappingHandlerMapping' defined in class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]: Invocation of init method failed; nested exception is java.lang.IllegalStateException: Ambiguous mapping. Cannot map 'appController' method 
public org.springframework.web.servlet.ModelAndView br.com.mblabs.controller.AppController.index(org.springframework.security.oauth2.client.authentication.OAuth2AuthenticationToken)
to { /}: There is already 'appController' bean method
public org.springframework.web.servlet.ModelAndView br.com.mblabs.controller.AppController.index() mapped.
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1778) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:845) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:877) ~[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549) ~[spring-context-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141) ~[spring-boot-2.1.8.RELEASE.jar:2.1.8.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:744) [spring-boot-2.1.8.RELEASE.jar:2.1.8.RELEASE]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:391) [spring-boot-2.1.8.RELEASE.jar:2.1.8.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:312) [spring-boot-2.1.8.RELEASE.jar:2.1.8.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215) [spring-boot-2.1.8.RELEASE.jar:2.1.8.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1204) [spring-boot-2.1.8.RELEASE.jar:2.1.8.RELEASE]
    at br.com.mblabs.EventoappApplication.main(EventoappApplication.java:32) [classes/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_111]
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_111]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_111]
    at java.lang.reflect.Method.invoke(Unknown Source) ~[na:1.8.0_111]
    at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-2.1.8.RELEASE.jar:2.1.8.RELEASE]
Caused by: java.lang.IllegalStateException: Ambiguous mapping. Cannot map 'appController' method 
public org.springframework.web.servlet.ModelAndView br.com.mblabs.controller.AppController.index(org.springframework.security.oauth2.client.authentication.OAuth2AuthenticationToken)
to { /}: There is already 'appController' bean method
public org.springframework.web.servlet.ModelAndView br.com.mblabs.controller.AppController.index() mapped.
    at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping$MappingRegistry.assertUniqueMethodMapping(AbstractHandlerMethodMapping.java:618) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping$MappingRegistry.register(AbstractHandlerMethodMapping.java:586) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.registerHandlerMethod(AbstractHandlerMethodMapping.java:312) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.lambda$detectHandlerMethods$1(AbstractHandlerMethodMapping.java:282) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at java.util.LinkedHashMap.forEach(Unknown Source) ~[na:1.8.0_111]
    at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.detectHandlerMethods(AbstractHandlerMethodMapping.java:280) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.processCandidateBean(AbstractHandlerMethodMapping.java:252) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.initHandlerMethods(AbstractHandlerMethodMapping.java:211) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.afterPropertiesSet(AbstractHandlerMethodMapping.java:199) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping.afterPropertiesSet(RequestMappingHandlerMapping.java:164) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1837) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1774) ~[spring-beans-5.1.9.RELEASE.jar:5.1.9.RELEASE]
    ... 21 common frames omitted