java - 如何知道 Android Java 中网页的最后修改日期和时间

Question

如何使用 Android Java 知道网页的最后修改日期？或者我如何请求

If-Modified-Since: Allows a 304 Not Modified to be returned if content is unchanged

使用 http header ？

Answer 1

我可以这样做:

URL url = null;
        try {
            url = new URL("http://www.example.com/example.pdf");
        } catch (MalformedURLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        HttpURLConnection httpCon = null;
        try {
            httpCon = (HttpURLConnection) url.openConnection();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        long date = httpCon.getLastModified();