springMvc拦截器

<mvc:interceptors><mvc:interceptor><mvc:mapping path="/api/v1/**"/><bean class="com.jcloud.ddos.ipanti.controller.interceptor.AuthInterceptor"/></mvc:interceptor><bean class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor"><property name="paramName" value="jdcloud_sitelang"/></bean></mvc:interceptors>

springBoot拦截器

@Configuration
@EnableAsync
@EnableScheduling
@ComponentScan("com.gdw.gradle")
public class Configration extends WebMvcConfigurerAdapter {@Overridepublic void addInterceptors(InterceptorRegistry registry) {registry.addInterceptor(new LocaleChangeInterceptor()).addPathPatterns("/**").excludePathPatterns("/exclude");registry.addInterceptor(new MyInterceptor());}
}

MappedInterceptor

当在spring xml文件中配置

		<mvc:interceptor><mvc:mapping path="/api/v1/**"/><bean class="com.jcloud.ddos.ipanti.controller.interceptor.AuthInterceptor"/></mvc:interceptor>

或在configuration类中配置

 registry.addInterceptor(new LocaleChangeInterceptor()).addPathPatterns("/**").excludePathPatterns("/exclude");

spring自动将拦截器解析为MappedInterceptor类型，对应配置的拦截路径
其他将返回拦截器本身对象；

源码解析

configuration中调用InterceptorRegistry类的addInterceptor方法

/*** Adds the provided {@link HandlerInterceptor}.* @param interceptor the interceptor to add* @return An {@link InterceptorRegistration} that allows you optionally configure the* registered interceptor further for example adding URL patterns it should apply to.*/public InterceptorRegistration addInterceptor(HandlerInterceptor interceptor) {InterceptorRegistration registration = new InterceptorRegistration(interceptor);registrations.add(registration);return registration;}

其中将传入的拦截器包装为InterceptorRegistration 对象
InterceptorRegistry对象中持有一个private final List registrations的List对象，将包装后的InterceptorRegistration 添加到registrations列表中并返回包装对象InterceptorRegistration 。
链式调用addPathPatterns方法时向包装对象InterceptorRegistration 添加拦截路径。
当调用InterceptorRegistry对象的getInterceptors方法时

protected List<Object> getInterceptors() {List<Object> interceptors = new ArrayList<Object>();for (InterceptorRegistration registration : registrations) {interceptors.add(registration.getInterceptor());}return interceptors ;}

将循环调用registrations列表中每一个注册过的InterceptorRegistration对象的getInterceptor方法
而InterceptorRegistration的getInterceptor方法：

protected Object getInterceptor() {if (this.includePatterns.isEmpty() && this.excludePatterns.isEmpty()) {return this.interceptor;}String[] include = toArray(this.includePatterns);String[] exclude = toArray(this.excludePatterns);MappedInterceptor mappedInterceptor = new MappedInterceptor(include, exclude, this.interceptor);if (this.pathMatcher != null) {mappedInterceptor.setPathMatcher(this.pathMatcher);}return mappedInterceptor;}

会根据是否传入includePatterns及excludePatterns判断是否包装为一个MappedInterceptor；