一.概述
文本探讨了SpringBoot的自动装配原理对于有关web的自动配置，其主要有四个配置类。
- ServletWebServerFactoryAutoConfiguration
自动配置和初始化一个内嵌的 Servlet Web 服务器
- DispatcherServletAutoConfiguration
用于自动配置 Spring MVC 核心组件DispatcherServlet
- WebMvcAutoConfiguration
用于自动配置 Spring MVC 基础设施的类，如视图解析器、静态资源处理、类型转换、数据绑定、消息转换器（JSON）、格式化器以及众多默认设置
- ErrorMvcAutoConfiguration
用于自动配置错误处理机制的类
测试代码如下：
package com.example.springdemo.demos.a06;
import org.springframework.boot.autoconfigure.web.servlet.DispatcherServletAutoConfiguration;
import org.springframework.boot.autoconfigure.web.servlet.ServletWebServerFactoryAutoConfiguration;
import org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration;
import org.springframework.boot.autoconfigure.web.servlet.error.ErrorMvcAutoConfiguration;
import org.springframework.boot.web.servlet.context.AnnotationConfigServletWebApplicationContext;
import org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.DeferredImportSelector;
import org.springframework.context.annotation.Import;
import org.springframework.core.type.AnnotationMetadata;
/**
* @author zhou
* @version 1.0
* @description TODO
* @date 2025/8/23 22:22
*/
public class TestMvcAuto {
public static void main(String[] args) {
AnnotationConfigServletWebServerApplicationContext context = new AnnotationConfigServletWebServerApplicationContext();
context.registerBean(Config.class);
context.refresh();
for (String name : context.getBeanDefinitionNames()){
String source = context.getBeanDefinition(name).getDescription();
if(source != null){
System.out.println(name+"来源: "+source);
}
}
context.close();
}
@Configuration
@Import(MyImportSelector.class)
static class Config{
}
static class MyImportSelector implements DeferredImportSelector{
@Override
public String[] selectImports(AnnotationMetadata importingClassMetadata) {
return new String[]{
ServletWebServerFactoryAutoConfiguration.class.getName(),
DispatcherServletAutoConfiguration.class.getName(),
WebMvcAutoConfiguration.class.getName(),
ErrorMvcAutoConfiguration.class.getName()
};
}
}
}测试结果：
tomcatServletWebServerFactory来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/ServletWebServerFactoryConfiguration$EmbeddedTomcat.class]
servletWebServerFactoryCustomizer来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/ServletWebServerFactoryAutoConfiguration.class]
tomcatServletWebServerFactoryCustomizer来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/ServletWebServerFactoryAutoConfiguration.class]
dispatcherServlet来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/DispatcherServletAutoConfiguration$DispatcherServletConfiguration.class]
dispatcherServletRegistration来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/DispatcherServletAutoConfiguration$DispatcherServletRegistrationConfiguration.class]
requestMappingHandlerAdapter来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
requestMappingHandlerMapping来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
welcomePageHandlerMapping来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
localeResolver来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
themeResolver来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
flashMapManager来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
mvcConversionService来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
mvcValidator来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
mvcContentNegotiationManager来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
mvcPatternParser来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
mvcUrlPathHelper来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
mvcPathMatcher来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
viewControllerHandlerMapping来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
beanNameHandlerMapping来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
routerFunctionMapping来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
resourceHandlerMapping来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
mvcResourceUrlProvider来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
defaultServletHandlerMapping来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
handlerFunctionAdapter来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
mvcUriComponentsContributor来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
httpRequestHandlerAdapter来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
simpleControllerHandlerAdapter来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
handlerExceptionResolver来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
mvcViewResolver来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
mvcHandlerMappingIntrospector来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
viewNameTranslator来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]
defaultViewResolver来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$WebMvcAutoConfigurationAdapter.class]
viewResolver来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$WebMvcAutoConfigurationAdapter.class]
requestContextFilter来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$WebMvcAutoConfigurationAdapter.class]
formContentFilter来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration.class]
error来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/error/ErrorMvcAutoConfiguration$WhitelabelErrorViewConfiguration.class]
beanNameViewResolver来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/error/ErrorMvcAutoConfiguration$WhitelabelErrorViewConfiguration.class]
conventionErrorViewResolver来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/error/ErrorMvcAutoConfiguration$DefaultErrorViewResolverConfiguration.class]
errorAttributes来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/error/ErrorMvcAutoConfiguration.class]
basicErrorController来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/error/ErrorMvcAutoConfiguration.class]
errorPageCustomizer来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/error/ErrorMvcAutoConfiguration.class]
preserveErrorControllerTargetClassPostProcessor来源: class path resource [org/springframework/boot/autoconfigure/web/servlet/error/ErrorMvcAutoConfiguration.class]可以看到，配置类里面导入了许多有关处理web请求的类，例如：适配器，影射器等等。
二.配置类分析
1.EmbeddedTomcat类的导入
从上面可以看到SpringBoot是怎么导入内嵌Tomcat类的，只有当项目中存在Servlet, Tomcat, UpgradeProtocol类的时候才会导入。
2.DispatcherServletConfiguration类
用于导入DispatcherServlet相关的配置，该类存在的前提是ServletRegistration类存在
并且自动导入WebMvcProperties配置
该类是有关web的相关配置类，项目的主配置文件中以spring.mvc为前缀的属性值会和该类做绑定。