gwt - 从 gwt 中的 url 下载文件

Question

我想从互联网上下载一个文件，我有那个文件的 url。所以我写了一个下载servlet：

public class DownloadServlet extends HttpServlet {
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws IOException {
        String pathToDownload = request.getParameter("url");

        URL url = new URL(pathToDownload);
        URLConnection uc = url.openConnection();
        String contentType = uc.getContentType();
        int contentLength = uc.getContentLength();
        InputStream is = uc.getInputStream();

        response.setContentType(contentType);
        // resp.setHeader("Content-Disposition", "attachment; filename*=\"utf-8''" + filename + "");
        ServletOutputStream os = response.getOutputStream();
        byte[] b = new byte[2048];
        int length;

        while ((length = is.read(b)) != -1) {
            os.write(b, 0, length);
        }
        is.close();
        os.close();
    }
}

在此我想在用户单击文件时显示弹出窗口是否保存所以有

resp.setHeader("Content-Disposition", "attachment; filename*=\"utf-8''" + filename + "");

但我希望文件名与 internate 上的文件名相同，所以上面的代码片段还需要什么？

Answer 1

将子字符串从最后一个“/”剪切到 URL 字符串的末尾 - 这是您的文件名。

Answer 2

String disposition = httpConn.getHeaderField("Content-Disposition");
            if (disposition != null) {
                // extracts file name from header field

                int index = disposition.indexOf("filename=");
                if (index != 0) {
                    fileName = disposition.substring(index + 9,
                            disposition.length());
                }
            } else {
                // extracts file name from URL

                fileName = link.substring(link.lastIndexOf("/") + 1,
                        link.length());
            }