SpringBoot配置拦截器

1.创建一个自定义拦截器，实现HandlerInterceptor

package com.hmdp.utils;
import com.hmdp.dto.UserDTO;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
/**
 * 拦截器
 */
public class LoginInterceptor implements HandlerInterceptor {
    /**
     * 前置拦截器 --- 进入controller之前进行登录校验
     *
     * @param request
     * @param response
     * @param handler
     * @return
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        //1.获取session
        HttpSession session = request.getSession();
        //2.获取session中的用户
        Object user = session.getAttribute("user");
        //3.判断用户是否存在
        if (user==null){
            //4.不存在，拦截 返回401未授权
            response.setStatus(401);
            return false;
        }
        //5.存在，保存用户到ThreadLocal
        UserHolder.saveUser((UserDTO) user);
        //6.放行
        return true;
    }
    /**
     * 增强拦截器--空过
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
    }
    /**
     *  后置拦截器 --- 用户业务执行完毕，销毁对应的用户信息
     */
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        UserHolder.removeUser();
    }
}

2.调用配置类拦截器

package com.hmdp.config;
import com.hmdp.utils.LoginInterceptor;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class MvcConfig implements WebMvcConfigurer {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        //添加拦截器，、
        //配置不拦截的路径
        registry.addInterceptor(new LoginInterceptor()).excludePathPatterns(
                "/user/code",
                "/user/login",
                "/blog.hot",
                "/shop/**",
                "/shop-type/**",
                "/voucher/**"
        );
    }
}