这里了解一下restful api的拦截，文本主要介绍三种方式来对api进行拦截，参考本文可实现拦截api，进行一些附加操作，比如打印拦截到的方法所在类名，获取原始的request，拦截到api的调用的方法名，还可以根据需要实现打印出方法的参数。当然，下面介绍的拦截器、过滤器、切片功能不全一样，侧重点不同。希望可以给大家带来帮助。
1、自定义过滤器：
/** * @author: zhoulitong * @date: 2018/4/23 * @description: */ @Component public class TimeFilter implements Filter { @Override public void init(FilterConfig filterConfig) throws ServletException { System.out.println("time filter init"); } /** * 处理服务的请求时间 * @param request * @param response * @param chain * @throws IOException * @throws ServletException */ @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { //System.out.println("time filter start"); long start = System.currentTimeMillis(); chain.doFilter(request,response); //System.out.println("time filter 耗时:" + (System.currentTimeMillis() - start)); //System.out.println("time filter finish"); } @Override public void destroy() { //System.out.println("time filter destroy"); } }2、配置过滤器注入到spring容器：
/** * @author: zhoulitong * @date: 2018/4/23 * @description: */ @Configuration public class WebConfig{ @Bean public FilterRegistrationBean timeFilter(){ FilterRegistrationBean registrationBean = new FilterRegistrationBean(); TimeFilter timeFilter = new TimeFilter(); registrationBean.setFilter(timeFilter); List<String> urls = new ArrayList<>(); //此过滤器在以下url中会起作用 urls.add("/*"); registrationBean.setUrlPatterns(urls); return registrationBean; } }3、特点：此种方式配置可以实现自定义过滤URL的操作，不可从request中拿到
1、自定义拦截器：
/** * @author: zhoulitong * @date: 2018/4/23 * @description: preHandle在控制器方法调用之前执行，postHandle在控制器方法正常执行后执行，afterCompletion不管控制器方法执行成功与否，都会执行;拦截器优于过滤器的地方就是拦截器有handler这个参数可以了解到针对哪个具体的方法进行了拦截。 */ @Component public class TimeInterceptor implements HandlerInterceptor { @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { System.out.println("preHandle"); //打印类名 System.out.println(((HandlerMethod)handler).getBean().getClass().getName()); //打印方法名 System.out.println(((HandlerMethod)handler).getMethod().getName()); request.setAttribute("startTime",System.currentTimeMillis()); return true; } @Override public void postHandle(HttpServletRequest request, HttpServletResponse response, Object o, ModelAndView modelAndView) throws Exception { System.out.println("postHandle"); Long start = (Long)request.getAttribute("startTime"); System.out.println("time intercept 耗时：" + (System.currentTimeMillis() - start)); } @Override public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object o, Exception ex) throws Exception { System.out.println("afterCompletion"); Long start = (Long)request.getAttribute("startTime"); System.out.println("time intercept 耗时：" + (System.currentTimeMillis() - start)); System.out.println("ex is" + ex); } }2、配置拦截器注入到spring容器（配置类需要继承WebMvcConfigurerAdapter，重写addInterceptors，手动添加自定义拦截器来到达注入的目的），也可为异步请求加入拦截器
/** * @author: zhoulitong * @date: 2018/4/23 * @description: 配置TimeInterceptor需要extends WebMvcConfigurerAdapter */ @Configuration public class WebConfig extends WebMvcConfigurerAdapter { @Autowired private TimeInterceptor timeInterceptor; /** * 针对异步的拦截器配置，拦截异步请求 * @param configurer */ @Override public void configureAsyncSupport(AsyncSupportConfigurer configurer) { super.configureAsyncSupport(configurer); //比如如下给异步服务请求添加拦截器 //configurer.registerCallableInterceptors((CallableProcessingInterceptor) timeInterceptor); } @Override public void addInterceptors(InterceptorRegistry registry) { registry.addInterceptor(timeInterceptor); } }3、特点：此种方式可以获取到拦截的类名称、方法名称，不能获取到方法参数，原因是在dispatcherservlet源码中，经过preHandle才对方法参数通过request里面开始处理拼接）
1、自定义切片：
@Aspect @Component public class TimeAspect { //切入点 @Around("execution(* com.zlt.web.controller.UserController.*(..))") //增强 public Object handleControllerMethod(ProceedingJoinPoint pjp) throws Throwable { System.out.print("time aspect start"); Object[] args = pjp.getArgs(); for (Object arg :args){ System.out.println("arg is" + arg); } long start = System.currentTimeMillis(); //调用被拦截的方法 Object object = pjp.proceed(); System.out.println("time filter 耗时：" + (System.currentTimeMillis() - start)); System.out.println("time aspect end"); return object; } }2、特点：可以拦截到类名、方法名，方法参数名
过滤器：可以拿到原始的HTTP请求和响应信息，拿不到处理请求的方法值信息 拦截器：既可以拿到HTTP请求和响应信息，也可以拿到请求的方法信息，拿不到方法调用的参数值信息 切片：可以拿到请求方法的传入参数值，拿不到原始的HTTP请求和响应的对象
正常运行顺序为：filter-interceptor-aspect 异常情况下：aspect-interceptor-filter
