1：编写一个类  实现 HandlerInterceptor接口

@Componentpublic class TestInterceptor implements HandlerInterceptor {

　　//前置方法  进入controller之前执行  可用于校验token权限
    @Override
    public boolean preHandle(HttpServletRequest request,
                             HttpServletResponse response, Object handler) throws Exception {

　　　　//controller执行之前，进行拦截的业务代码
return true;//放行
    }

　　//后置方法  controller执行之后执行
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        
    }



　　//视图渲染后执行方法 
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {

    }
}

 

2：注册拦截器到spring容器 

　　编写一个配置类，实现WebMvcConfigurer接口

/**
 * springboot将拦截器注入spring容器
 */
@Configuration
public class WebConfig implements WebMvcConfigurer {

    @Autowired
    private TestInterceptor testInterceptor;


    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        //拦截器拦截所有路径
        registry.addInterceptor(testInterceptor).addPathPatterns("/**");
    }
}