设置web.xml使用基于Java的配置报错

WebConfig:

``package config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.multipart.MultipartResolver;
import org.springframework.web.multipart.support.StandardServletMultipartResolver;
import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer;
import org.springframework.web.servlet.view.freemarker.FreeMarkerViewResolver;

@Configuration
@EnableWebMvc
@ComponentScan( "com")
public class WebConfig extends WebMvcConfigurerAdapter{

/**
 *配置静态资源处理 
 *
 */
public void configureDefaultServerletHandling(DefaultServletHandlerConfigurer configurer){
    configurer.enable();
}

/**
 *配置视图解析器 
 */
@Bean
public FreeMarkerConfigurer freeMarkerConfigurer() {
    FreeMarkerConfigurer configurer = new FreeMarkerConfigurer();
    configurer.setTemplateLoaderPath("/WEB-INF/");
    return configurer;
}

@Bean
public FreeMarkerViewResolver freeMarkerViewResover(){
    FreeMarkerViewResolver freeMarker = new FreeMarkerViewResolver();
    freeMarker.setSuffix(".ftl");
    freeMarker.setContentType("utf-8");
    return freeMarker;
}

/**
 * 配置multipart解析器
 */
@Bean
public MultipartResolver multipartResolver(){
    return new StandardServletMultipartResolver();
}

}
`

RootConfig:

package config;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.ComponentScan.Filter;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.FilterType;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;

@Configuration
@ComponentScan(excludeFilters={@Filter(type=FilterType.ANNOTATION,value=EnableWebMvc.class)})
public class RootConfig {

}

web.xml:

<?xml version="1.0" encoding="UTF-8"?>

spring_mvc_demo

index.html
index.htm
index.jsp
default.html
default.htm
default.jsp

<context-param>
    <param-name>contextClass</param-name>
    <param-value>org.springframework.web.context.support.AnnotationConfigWebApplicationContext</param-value>
</context-param>

<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>config.RootConfig</param-value>
</context-param>

<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>





<!-- The front controller of this Spring Web application, responsible for handling all application requests -->
<servlet>
    <servlet-name>appServlet</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
        <param-name>contextClass</param-name>
        <param-value>org.springframework.web.context.support.AnnotationConfigWebApplicationContext</param-value>
    </init-param>
    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>config.WebConfig</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
</servlet>

<!-- Map all requests to the DispatcherServlet for handling -->
<servlet-mapping>
    <servlet-name>appServlet</servlet-name>
    <url-pattern>*.do</url-pattern>
</servlet-mapping>

报错内容：

2018-07-28 18:33:21.710:WARN:oejw.WebAppContext:main: Failed startup of context o.e.j.w.WebAppContext@4b0b0854{/,file:///Users/lixiuming/project/spring_mvc_demo/WebContent/,UNAVAILABLE}
org.springframework.beans.factory.BeanDefinitionStoreException: Failed to parse configuration class [config.RootConfig]; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.beans.factory.support.BeanNameGenerator]: Specified class is an interface
at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:180)
at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:308)
at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:228)
at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:270)
at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:93)
at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:686)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:524)
at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:444)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:326)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:107)
at org.eclipse.jetty.server.handler.ContextHandler.callContextInitialized(ContextHandler.java:843)
at org.eclipse.jetty.servlet.ServletContextHandler.callContextInitialized(ServletContextHandler.java:533)
at org.eclipse.jetty.server.handler.ContextHandler.startContext(ContextHandler.java:816)
at org.eclipse.jetty.servlet.ServletContextHandler.startContext(ServletContextHandler.java:345)
at org.eclipse.jetty.webapp.WebAppContext.startWebapp(WebAppContext.java:1406)
at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1368)
at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:778)
at org.eclipse.jetty.servlet.ServletContextHandler.doStart(ServletContextHandler.java:262)
at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:522)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:131)
at org.eclipse.jetty.server.Server.start(Server.java:427)
at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:105)
at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:61)
at org.eclipse.jetty.server.Server.doStart(Server.java:394)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
at starter.SimplestServer.main(SimplestServer.java:17)
Caused by:
org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.beans.factory.support.BeanNameGenerator]: Specified class is an interface
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:99)
at org.springframework.context.annotation.ComponentScanAnnotationParser.parse(ComponentScanAnnotationParser.java:88)
at org.springframework.context.annotation.ConfigurationClassParser.doProcessConfigurationClass(ConfigurationClassParser.java:268)
at org.springframework.context.annotation.ConfigurationClassParser.processConfigurationClass(ConfigurationClassParser.java:230)
at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:197)
at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:166)
at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:308)
at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:228)
at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:270)
at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:93)
at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:686)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:524)
at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:444)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:326)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:107)
at org.eclipse.jetty.server.handler.ContextHandler.callContextInitialized(ContextHandler.java:843)
at org.eclipse.jetty.servlet.ServletContextHandler.callContextInitialized(ServletContextHandler.java:533)
at org.eclipse.jetty.server.handler.ContextHandler.startContext(ContextHandler.java:816)
at org.eclipse.jetty.servlet.ServletContextHandler.startContext(ServletContextHandler.java:345)
at org.eclipse.jetty.webapp.WebAppContext.startWebapp(WebAppContext.java:1406)
at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1368)
at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:778)
at org.eclipse.jetty.servlet.ServletContextHandler.doStart(ServletContextHandler.java:262)
at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:522)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:131)
at org.eclipse.jetty.server.Server.start(Server.java:427)
at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:105)
at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:61)
at org.eclipse.jetty.server.Server.doStart(Server.java:394)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
at starter.SimplestServer.main(SimplestServer.java:17)
2018-07-28 18:33:21.756:INFO:oejs.AbstractConnector:main: Started ServerConnector@1895f294{HTTP/1.1,[http/1.1]}{0.0.0.0:8080}
2018-07-28 18:33:21.758:INFO:oejs.Server:main: Started @1404ms

首先我也不是很懂，但仔细看了一下你的报错，问题是出现在这里
org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.beans.factory.support.BeanNameGenerator]: Specified class is an interface
也就是说在初始化BeanNameGenerator的时候就报了错，那你可以看一看是不是这里的标签出了错，或者说是在启动的时候什么注解与你初始化这个类
起了冲突，我只分析出这么多 — —！

org.springframework.beans.BeanInstantiationException: Failed to instantiate [**org.springframework.beans.factory.support.BeanNameGenerator]**: Specified class is an interface
问题出现在这个类上，这个类是一个接口，不能作为参数，你看看哪里有用到这个类的地方，重点：这个类是一个接口。好好想想这句话。