package net.ybclass.online_ybclass.interceptor;

import org.springframework.http.HttpMethod;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

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

public class CorsInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        //表示接受任意域名的请求,也可以指定域名
        response.setHeader("Access-Control-Allow-Origin", request.getHeader("origin"));

        //该字段可选，是个布尔值，表示是否可以携带cookie
        response.setHeader("Access-Control-Allow-Credentials", "true");

        response.setHeader("Access-Control-Allow-Methods", "GET, HEAD, POST, PUT, PATCH, DELETE, OPTIONS");

        response.setHeader("Access-Control-Allow-Headers", "*");
        //这里可以不加，但是其他语言开发的话记得处理options请求
        /**
         * 非简单请求是对那种对服务器有特殊要求的请求，
         * 比如请求方式是PUT或者DELETE，或者Content-Type字段类型是application/json。
         * 都会在正式通信之前，增加一次HTTP请求，称之为预检。浏览器会先询问服务器，当前网页所在域名是否在服务器的许可名单之中，
         * 服务器允许之后，浏览器会发出正式的XMLHttpRequest请求
         */
        if(HttpMethod.OPTIONS.toString().equals(request.getMethod())){
            return true;
        }
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {

    }
}

package net.ybclass.online_ybclass.config;

import net.ybclass.online_ybclass.interceptor.CorsInterceptor;
import net.ybclass.online_ybclass.interceptor.LoginInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

/**
 * 拦截器配置
 * 不用权限可以访问url /api/v1/pub/
 * 要登陆可以访问url /api/v1/pri/
 */
@Configuration
public class InterceptorConfig implements WebMvcConfigurer {
    @Bean
    LoginInterceptor loginInterceptor(){
        return new LoginInterceptor();
    }
    @Bean
    CorsInterceptor corsInterceptor(){return new CorsInterceptor();}
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        //拦截全部路径，这个跨域了，需要放在最上面
        registry.addInterceptor(corsInterceptor()).addPathPatterns("/**");
        registry.addInterceptor(loginInterceptor())
                .addPathPatterns("/api/v1/pri/*/*/**")//配置拦截的路径
                .excludePathPatterns("/api/v1/pri/user/login","/api/v1/pri/user/register"); //不拦截那些路径
        WebMvcConfigurer.super.addInterceptors(registry);
    }
}