Java是一種廣泛使用的編程語言，它支持視頻上傳和下載。視頻上傳是將視頻文件從本地計算機上傳到遠程服務器的過程。視頻下載是將視頻文件從遠程服務器下載到本地計算機的過程。在Java中，我們可以使用HttpURLConnection類來實現這兩個過程。

視頻上傳：

File videoFile = new File("video.mp4");
URL url = new URL("http://www.example.com/upload");
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("POST");
connection.setDoOutput(true);
FileInputStream fileInputStream = new FileInputStream(videoFile);
OutputStream outputStream = connection.getOutputStream();
byte[] buffer = new byte[4096];
int bytesRead;
while ((bytesRead = fileInputStream.read(buffer)) != -1) {
outputStream.write(buffer, 0, bytesRead);
}
outputStream.flush();
outputStream.close();
fileInputStream.close();
int responseCode = connection.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_OK) {
//上傳成功
} else {
//上傳失敗
}

視頻下載：

URL url = new URL("http://www.example.com/download/video.mp4");
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
int contentLength = connection.getContentLength();
InputStream inputStream = connection.getInputStream();
File videoFile = new File("video.mp4");
FileOutputStream fileOutputStream = new FileOutputStream(videoFile);
byte[] buffer = new byte[4096];
int bytesRead;
int totalBytesRead = 0;
while ((bytesRead = inputStream.read(buffer)) != -1) {
fileOutputStream.write(buffer, 0, bytesRead);
totalBytesRead += bytesRead;
//下載進度
int progress = (int) ((float) totalBytesRead / contentLength * 100);
}
fileOutputStream.flush();
fileOutputStream.close();
inputStream.close();
//下載完成

以上代碼演示了如何通過Java實現視頻上傳和下載。使用HttpURLConnection類可以讓我們輕松地連接遠程服務器并發送請求，同時也可以讀取服務器響應并處理它們。視頻上傳和下載是現代網絡應用程序中必不可少的功能，這些Java代碼提供了一個良好的起點。