Springboot——拦截器

1. 创建一个类实现HandlerInterceptor接口
2. 添加到spring容器中

简单例子：

public class MyInterceptor implements HandlerInterceptor {

    /**
     * 请求处理之前执行
     * @param request
     * @param response
     * @param handler
     * @return
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("=======请求处理之前执行=========");
        return false;
    }

    /**
     * 请求进行处理之后执行
     * @param request
     * @param response
     * @param handler
     * @param modelAndView
     * @throws Exception
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("===========请求进行处理之后执行==========");
    }

    /**
     * 当前对应的interceptor的perHandle方法的返回值为true时,postHandle执行完成并渲染页面后执行
     * @param request
     * @param response
     * @param handler
     * @param ex
     * @throws Exception
     */
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("==========当前对应的interceptor的perHandle方法的返回值为true时,postHandle执行完成并渲染页面后执行===========");
    }
}

配置适配器

@Configuration
public class MyMvcConfig implements WebMvcConfigurer {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new MyInterceptor())
                .addPathPatterns("/signIn") //需要拦截的路径
                .excludePathPatterns("/login","/login.html"); //不需要拦截的路径
    }
}

 拦截器用途很广，比如可以用来进行接口权限控制，登陆，日志记录等等。