java过滤器（Filter）、Spring拦截器（Handler）

首先，tomcat容器中有Servlet容器和Spring容器，java过滤器。

Filter 是在 Servlet 规范中定义的，是 Servlet 容器支持的；Handler是在 Spring 容器内的，是 Spring 框架支持的

方法的执行时机不一样：Filter是在Handler前执行的

不同的实现

@Component
public class MyFilter implements Filter {
    
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

        System.out.println("Filter 前置");
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {

        System.out.println("Filter 处理中");
        filterChain.doFilter(servletRequest, servletResponse);
    }

    @Override
    public void destroy() {

        System.out.println("Filter 后置");
    }
}

Handler

@Component
public class MyInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

        System.out.println("Interceptor 前置");
        return true;
    }

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

        System.out.println("Interceptor 处理中");
    }

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

        System.out.println("Interceptor 后置");
    }
}

接着将自定义好的拦截器处理类进行注册，并通过addPathPatterns、excludePathPatterns等属性设置需要拦截或需要排除的URL。

@Configuration
public class MyMvcConfig implements WebMvcConfigurer {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new MyInterceptor()).addPathPatterns("/**");
        registry.addInterceptor(new MyInterceptor1()).addPathPatterns("/**");
    }
}