ajax - 如何忽略回发调用的过滤器

Question

我有一个需要 id 参数 (GET) 的过滤器。当我在导航链接中添加参数时，这很好用。但是当我停留在同一个站点时(例如 ajax 调用)，过滤器会大喊大叫，因为 id 参数丢失了。

如果请求来自 ajax，是否有机会忽略过滤器？
就像是

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
    if (FacesContext.getCurrentInstance().isPostback()) {...}
    ...
}

?

Answer 1

我找到了一个工作正常的解决方案

private boolean isAJAXRequest(HttpServletRequest request) {
    boolean check = false;
    String facesRequest = request.getHeader("Faces-Request");
    if (facesRequest != null && facesRequest.equals("partial/ajax")) {
        check = true;
    }
    return check; 
}

在过滤器的开头，只需添加如下:

@Override 
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
    HttpServletRequest req = (HttpServletRequest) request;

    if(isAJAXRequest(req)){
        System.out.println("IGNORE THIS FILTER, AJAX");
        chain.doFilter(request, response);
        return;
    }
    ...
}