Spring Boot 2 的MVC配置改变

Spring Boot 升级2.0之后,弃用 WebMvcConfigurerAdapter

Spring Boot 2的Spring版本升级到Spring5,而Spring5为了充分得利用Java8的新特型,很多代码进行了重写,其中就有 WebMvcConfigurer 接口。

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public interface WebMvcConfigurer {
/**
* Helps with configuring HandlerMappings path matching options such as trailing slash match,
* suffix registration, path matcher and path helper.
* Configured path matcher and path helper instances are shared for:
* <ul>
* <li>RequestMappings</li>
* <li>ViewControllerMappings</li>
* <li>ResourcesMappings</li>
* </ul>
* @since 4.0.3
*/
default void configurePathMatch(PathMatchConfigurer configurer) {
}
/**
* Configure content negotiation options.
*/
default void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
}
/**
* Configure asynchronous request handling options.
*/
default void configureAsyncSupport(AsyncSupportConfigurer configurer) {
}
/**
* Configure a handler to delegate unhandled requests by forwarding to the
* Servlet container's "default" servlet. A common use case for this is when
* the {@link DispatcherServlet} is mapped to "/" thus overriding the
* Servlet container's default handling of static resources.
*/
default void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
}
/**
* Add {@link Converter}s and {@link Formatter}s in addition to the ones
* registered by default.
*/
default void addFormatters(FormatterRegistry registry) {
}
/**
* Add Spring MVC lifecycle interceptors for pre- and post-processing of
* controller method invocations. Interceptors can be registered to apply
* to all requests or be limited to a subset of URL patterns.
* <p><strong>Note</strong> that interceptors registered here only apply to
* controllers and not to resource handler requests. To intercept requests for
* static resources either declare a
* {@link org.springframework.web.servlet.handler.MappedInterceptor MappedInterceptor}
* bean or switch to advanced configuration mode by extending
* {@link org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport
* WebMvcConfigurationSupport} and then override {@code resourceHandlerMapping}.
*/
default void addInterceptors(InterceptorRegistry registry) {
}
/**
* Add handlers to serve static resources such as images, js, and, css
* files from specific locations under web application root, the classpath,
* and others.
*/
default void addResourceHandlers(ResourceHandlerRegistry registry) {
}
/**
* Configure cross origin requests processing.
* @since 4.2
*/
default void addCorsMappings(CorsRegistry registry) {
}
/**
* Configure simple automated controllers pre-configured with the response
* status code and/or a view to render the response body. This is useful in
* cases where there is no need for custom controller logic -- e.g. render a
* home page, perform simple site URL redirects, return a 404 status with
* HTML content, a 204 with no content, and more.
*/
default void addViewControllers(ViewControllerRegistry registry) {
}
/**
* Configure view resolvers to translate String-based view names returned from
* controllers into concrete {@link org.springframework.web.servlet.View}
* implementations to perform rendering with.
* @since 4.1
*/
default void configureViewResolvers(ViewResolverRegistry registry) {
}
/**
* Add resolvers to support custom controller method argument types.
* <p>This does not override the built-in support for resolving handler
* method arguments. To customize the built-in support for argument
* resolution, configure {@link RequestMappingHandlerAdapter} directly.
* @param resolvers initially an empty list
*/
default void addArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers) {
}
/**
* Add handlers to support custom controller method return value types.
* <p>Using this option does not override the built-in support for handling
* return values. To customize the built-in support for handling return
* values, configure RequestMappingHandlerAdapter directly.
* @param handlers initially an empty list
*/
default void addReturnValueHandlers(List<HandlerMethodReturnValueHandler> handlers) {
}
/**
* Configure the {@link HttpMessageConverter}s to use for reading or writing
* to the body of the request or response. If no converters are added, a
* default list of converters is registered.
* <p><strong>Note</strong> that adding converters to the list, turns off
* default converter registration. To simply add a converter without impacting
* default registration, consider using the method
* {@link #extendMessageConverters(java.util.List)} instead.
* @param converters initially an empty list of converters
*/
default void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
}
/**
* A hook for extending or modifying the list of converters after it has been
* configured. This may be useful for example to allow default converters to
* be registered and then insert a custom converter through this method.
* @param converters the list of configured converters to extend.
* @since 4.1.3
*/
default void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
}
/**
* Configure exception resolvers.
* <p>The given list starts out empty. If it is left empty, the framework
* configures a default set of resolvers, see
* {@link WebMvcConfigurationSupport#addDefaultHandlerExceptionResolvers(List)}.
* Or if any exception resolvers are added to the list, then the application
* effectively takes over and must provide, fully initialized, exception
* resolvers.
* <p>Alternatively you can use
* {@link #extendHandlerExceptionResolvers(List)} which allows you to extend
* or modify the list of exception resolvers configured by default.
* @param resolvers initially an empty list
* @see #extendHandlerExceptionResolvers(List)
* @see WebMvcConfigurationSupport#addDefaultHandlerExceptionResolvers(List)
*/
default void configureHandlerExceptionResolvers(List<HandlerExceptionResolver> resolvers) {
}
/**
* Extending or modify the list of exception resolvers configured by default.
* This can be useful for inserting a custom exception resolver without
* interfering with default ones.
* @param resolvers the list of configured resolvers to extend
* @since 4.3
* @see WebMvcConfigurationSupport#addDefaultHandlerExceptionResolvers(List)
*/
default void extendHandlerExceptionResolvers(List<HandlerExceptionResolver> resolvers) {
}
/**
* Provide a custom {@link Validator} instead of the one created by default.
* The default implementation, assuming JSR-303 is on the classpath, is:
* {@link org.springframework.validation.beanvalidation.OptionalValidatorFactoryBean}.
* Leave the return value as {@code null} to keep the default.
*/
@Nullable
default Validator getValidator() {
return null;
}
/**
* Provide a custom {@link MessageCodesResolver} for building message codes
* from data binding and validation error codes. Leave the return value as
* {@code null} to keep the default.
*/
@Nullable
default MessageCodesResolver getMessageCodesResolver() {
return null;
}
}

可以看到,这个接口改为提供默认实现的方式,因此 WebMvcConfigurerAdapter 抽象类已经不需要了,所以自定义的 WebMvcConfig 只需要实现 WebMvcConfigurer 接口。