我有FileDownloader類從谷歌驅動器下載文件,並且這些文件可以被其他類使用。我還需要以某種方式提取文件名。問題是,下面的解決方案適用於直接鏈接,但它不起作用,當鏈接縮短bit.ly例如... 你能告訴我如何改變代碼來獲得正確的文件名?如何在使用Java下載文件時獲取文件名?
public class FileDownloader {
private static final int BUFFER_SIZE = 4096;
public static void downloadFile(String fileURL, String saveDir)
throws IOException {
URL url = new URL(fileURL);
HttpURLConnection httpConn = (HttpURLConnection) url.openConnection();
int responseCode = httpConn.getResponseCode();
// checking HTTP response code first
if (responseCode == HttpURLConnection.HTTP_OK) {
String fileName = "";
String disposition = httpConn.getHeaderField("Content-Disposition");
String contentType = httpConn.getContentType();
int contentLength = httpConn.getContentLength();
if (disposition != null) {
// extracts file name from header field
int index = disposition.indexOf("filename*=UTF-8''");
if (index > 0) {
fileName = disposition.substring(index + 17,
disposition.length());
}
} else {
// extracts file name from URL
fileName = fileURL.substring(fileURL.lastIndexOf("/") + 1,
fileURL.length());
}
System.out.println("Content-Type = " + contentType);
System.out.println("Content-Disposition = " + disposition);
System.out.println("Content-Length = " + contentLength);
System.out.println("fileName = " + fileName);
// opens input stream from the HTTP connection
InputStream inputStream = httpConn.getInputStream();
String saveFilePath = saveDir + File.separator + fileName;
// opens an output stream to save into file
FileOutputStream outputStream = new FileOutputStream(saveFilePath);
int bytesRead = -1;
byte[] buffer = new byte[BUFFER_SIZE];
while ((bytesRead = inputStream.read(buffer)) != -1) {
outputStream.write(buffer, 0, bytesRead);
}
outputStream.close();
inputStream.close();
System.out.println("File downloaded");
} else {
System.out.println("No file to download. Server replied HTTP code: " + responseCode);
}
httpConn.disconnect();
}
嘗試檢查響應頭... –
嘗試更加具體在何處的錯誤發生。看看如何創建一個[mcve] –
有沒有其他的解決方案如何獲得你正在下載的文件的文件名? – Boris