Spring的拦截器HandlerInterceptor详解

public interface HandlerInterceptor {
    default boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        return true;
    }
    default void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable ModelAndView modelAndView) throws Exception {
    }
    default void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable Exception ex) throws Exception {
    }
}

public interface WebMvcConfigurer {
    default void configurePathMatch(PathMatchConfigurer configurer) {
    }
    default void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
    }
    default void configureAsyncSupport(AsyncSupportConfigurer configurer) {
    }
    default void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
    }
    default void addFormatters(FormatterRegistry registry) {
    }
    default void addInterceptors(InterceptorRegistry registry) {
    }
    default void addResourceHandlers(ResourceHandlerRegistry registry) {
    }
    default void addCorsMappings(CorsRegistry registry) {
    }
    default void addViewControllers(ViewControllerRegistry registry) {
    }
    default void configureViewResolvers(ViewResolverRegistry registry) {
    }
    default void addArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers) {
    }
    default void addReturnValueHandlers(List<HandlerMethodReturnValueHandler> handlers) {
    }
    default void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
    }
    default void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
    }
    default void configureHandlerExceptionResolvers(List<HandlerExceptionResolver> resolvers) {
    }
    default void extendHandlerExceptionResolvers(List<HandlerExceptionResolver> resolvers) {
    }
    @Nullable
    default Validator getValidator() {
        return null;
    }
    @Nullable
    default MessageCodesResolver getMessageCodesResolver() {
        return null;
    }
}

@Component
public class HeaderInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("进入拦截器=======执行前========");
        return true;
    }
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("进入拦截器=======执行中========");
    }
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("进入拦截器=======执行后========");
    }
}

package com.liubujun.springbootinterceptor.config;
import com.liubujun.springbootinterceptor.interceptor.HeaderInterceptor;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import javax.annotation.Resource;
import java.util.ArrayList;
import java.util.List;
/**
 * @Author: liubujun
 * @Date: 2022/10/10 19:55
 */
/**
 * 此处也可以继承WebMvcConfigurationSupport
 */
@Configuration
public class WebAppConfig implements WebMvcConfigurer {
    @Resource
    private HeaderInterceptor headerInterceptor;
    /**
     * 添加拦截规则
     * @param registry
     */
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        List<String> patterns = new ArrayList<>();
        patterns.add("/login/login");
        registry.addInterceptor(headerInterceptor)
                .addPathPatterns("/**") //所有的请求都要拦截。
                .excludePathPatterns(patterns); //将不需要拦截的接口请求排除在外
    }
    /**
     * //下面代码意思是:配置一个拦截器，如果访问路径时addResourceHandler中的这个路径（我这里是/**表示所有的路径），
     *  那么就映射到访问本地的addResourceLocations这个路径上，这样就可以看到该路径上的资源了
     * @param registry
     */
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/**") //配置需要添加静态资源请求的url
                .addResourceLocations("classpath:/pic/"); //配置静态资源路径
    }
}

@RestController
public class LoginController {
 
 
    @GetMapping("/login/login")
    public String testLoginInterceptor(){
        return "登录请求没有被拦截====》看控制台没有输出";
    }
 
    @GetMapping("/test/other")
    public String testOtherInterceptor(){
        return "该请求没有被拦截，看控制台有输出";
    }
}