WebMvcConfigurer 添加拦截器

问题

之前项目是springboot1.5版本的,后来想升级一下用2.0,但是在升级过后发现WebMvcConfigurerAdapter抽象类过时了

@Deprecated

public abstract class WebMvcConfigurerAdapter implements WebMvcConfigurer {

/**
 * {@inheritDoc}
 * <p>This implementation is empty.
 */
@Override
public void configurePathMatch(PathMatchConfigurer configurer) {
}

/**
 * {@inheritDoc}
 * <p>This implementation is empty.
 */
@Override
public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
}

/**
 * {@inheritDoc}
 * <p>This implementation is empty.
 */
@Override
public void configureAsyncSupport(AsyncSupportConfigurer configurer) {
}

/**
 * {@inheritDoc}
 * <p>This implementation is empty.
 */
@Override
public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
}

/**
 * {@inheritDoc}
 * <p>This implementation is empty.
 */
@Override
public void addFormatters(FormatterRegistry registry) {
}

/**
 * {@inheritDoc}
 * <p>This implementation is empty.
 */
@Override
public void addInterceptors(InterceptorRegistry registry) {
}

/**
 * {@inheritDoc}
 * <p>This implementation is empty.
 */
@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
}

/**
 * {@inheritDoc}
 * <p>This implementation is empty.
 */
@Override
public void addCorsMappings(CorsRegistry registry) {
}

/**
 * {@inheritDoc}
 * <p>This implementation is empty.
 */
@Override
public void addViewControllers(ViewControllerRegistry registry) {
}

/**
 * {@inheritDoc}
 * <p>This implementation is empty.
 */
@Override
public void configureViewResolvers(ViewResolverRegistry registry) {
}

/**
 * {@inheritDoc}
 * <p>This implementation is empty.
 */
@Override
public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
}

/**
 * {@inheritDoc}
 * <p>This implementation is empty.
 */
@Override
public void addReturnValueHandlers(List<HandlerMethodReturnValueHandler> returnValueHandlers) {
}

/**
 * {@inheritDoc}
 * <p>This implementation is empty.
 */
@Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
}

/**
 * {@inheritDoc}
 * <p>This implementation is empty.
 */
@Override
public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
}

/**
 * {@inheritDoc}
 * <p>This implementation is empty.
 */
@Override
public void configureHandlerExceptionResolvers(List<HandlerExceptionResolver> exceptionResolvers) {
}

/**
 * {@inheritDoc}
 * <p>This implementation is empty.
 */
@Override
public void extendHandlerExceptionResolvers(List<HandlerExceptionResolver> exceptionResolvers) {
}

/**
 * {@inheritDoc}
 * <p>This implementation returns {@code null}.
 */
@Override
@Nullable
public Validator getValidator() {
    return null;
}

/**
 * {@inheritDoc}
 * <p>This implementation returns {@code null}.
 */
@Override
@Nullable
public MessageCodesResolver getMessageCodesResolver() {
    return null;
}

}

WebMvcConfigurerAdapter是一个典型的适配器,这个抽象类中没有抽象方法,所有的方法都是对接口的一个空实现,这样的好处是用户类就只需要继承适配器类，只实现感兴趣的方法就行了.

springboot 2.0中这个抽象类已经过时,我们可以直接实现WebMvcConfigurer接口,2.0使用了java8的特性 default 方法

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;
}

}

2.0 中也可以使用WebMvcConfigurationSupport但这样会使自动配置失效,需要重新配置后才可以有效

@Override

protected void addResourceHandlers(ResourceHandlerRegistry registry) {

    registry.addResourceHandler("/static/**").addResourceLocations("classpath:/static/");

    super.addResourceHandlers(registry);

}

综上2.0中实现WebMvcConfigure接口,配置拦截器是最合适的