Java 弹簧&x27；当我使用异步servlet（Spring3.2）时，s ETag过滤器无效

最近，我们在servlet 3.0和spring 3.2中使用了异步功能，但是我们的ShallowEtagHeaderFilter根本没有效果，我想一定是框架在处理我的内容之前刷新了响应。。。

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如何解决？有人有经验吗？

参考Spring 4.3.5中ShallowEtagFilter的代码片段

protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
        throws ServletException, IOException {

    HttpServletResponse responseToUse = response;
    if (!isAsyncDispatch(request) && !(response instanceof ContentCachingResponseWrapper)) {
        responseToUse = new HttpStreamingAwareContentCachingResponseWrapper(response, request);
    }

    filterChain.doFilter(request, responseToUse);

    if (!isAsyncStarted(request) && !isContentCachingDisabled(request)) {
        updateResponse(request, responseToUse);
    }
}

/**
     * Whether request processing is in asynchronous mode meaning that the
     * response will not be committed after the current thread is exited.
     * @param request the current request
     * @since 3.2
     * @see WebAsyncManager#isConcurrentHandlingStarted()
     */
    protected boolean isAsyncStarted(HttpServletRequest request) {
        return WebAsyncUtils.getAsyncManager(request).isConcurrentHandlingStarted();
    }

当您使用AsyncServlet时，将不满足该条件，这意味着不会调用生成etag的业务逻辑