SpringBoot自定义拦截器（多个拦截器）

在 Spring Boot 中要实现自定义拦截器需要实现 HandlerInterceptor 接口，并重写 preHandle、postHandle 和 afterCompletion 方法：

import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@Component
public class MyInterceptor implements HandlerInterceptor {

    /**
     * @return 返回 true 放行、放回 false 拦截
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("进入拦截器，前置通知" + request.getRequestURI());
        //过滤掉 确认的 options 请求
        if ("OPTIONS".equals(request.getMethod())) {
            return true;
        }

        String token = request.getHeader("token");

        if (token != null) {
            return true;
        }

        return false;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("后置通知");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("最终通知");
    }
}

然后实现 WebMvcConfigurer 接口重写 addInterceptor方法：

@Configuration
public class MyConfig implements WebMvcConfigurer {

    @Autowired
    MyInterceptor myInterceptor;

    @Override
    public void addInterceptors(InterceptorRegistry registry) {

        registry.addInterceptor(myInterceptor)    // 添加自定义拦截器
                .excludePathPatterns("/index") // 设置放行路径
                .addPathPatterns("/**");       // 设置拦截路径
        
        // 如果有多个拦截器，继续添加即可
        //registry.addInterceptor(myInterceptor2)    
        //       .excludePathPatterns("/index") 
        //        .addPathPatterns("/**");       
    }
}

多个拦截器的执行顺序如下：（盗一张图）

最先执行 preHandle 的拦截器的 postHandle 和 afterCompletion 都是最后执行的