1. 使用URL類的openStream()方法下載文件：

URL url = new URL(fileUrl);
InputStream inputStream = url.openStream();
FileOutputStream outputStream = new FileOutputStream(savePath);
byte[] buffer = new byte[1024];
int bytesRead;
while ((bytesRead = inputStream.read(buffer)) != -1) {
outputStream.write(buffer, 0, bytesRead);
}
outputStream.close();
inputStream.close();

2. 使用URLConnection類下載文件：

URL url = new URL(fileUrl);
HttpURLConnection httpConn = (HttpURLConnection) url.openConnection();
int responseCode = httpConn.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_OK) {
InputStream inputStream = httpConn.getInputStream();
FileOutputStream outputStream = new FileOutputStream(savePath);
byte[] buffer = new byte[1024];
int bytesRead;
while ((bytesRead = inputStream.read(buffer)) != -1) {
outputStream.write(buffer, 0, bytesRead);
}
outputStream.close();
inputStream.close();
}
httpConn.disconnect();

3. 使用Apache HttpClient庫下載文件：

CloseableHttpClient httpClient = HttpClientBuilder.create().build();
HttpGet httpGet = new HttpGet(fileUrl);
CloseableHttpResponse response = httpClient.execute(httpGet);
HttpEntity entity = response.getEntity();
if (entity != null) {
InputStream inputStream = entity.getContent();
FileOutputStream outputStream = new FileOutputStream(savePath);
byte[] buffer = new byte[1024];
int bytesRead;
while ((bytesRead = inputStream.read(buffer)) != -1) {
outputStream.write(buffer, 0, bytesRead);
}
outputStream.close();
inputStream.close();
}
httpClient.close();
response.close();

4. 使用Java NIO下載文件：

URL url = new URL(fileUrl);
ReadableByteChannel channel = Channels.newChannel(url.openStream());
FileOutputStream outputStream = new FileOutputStream(savePath);
outputStream.getChannel().transferFrom(channel, 0, Long.MAX_VALUE);
outputStream.close();
channel.close();

5. 使用Java IO和BufferedStream下載文件：

URL url = new URL(fileUrl);
BufferedInputStream inputStream = new BufferedInputStream(url.openStream());
FileOutputStream outputStream = new FileOutputStream(savePath);
byte[] buffer = new byte[1024];
int bytesRead;
while ((bytesRead = inputStream.read(buffer)) != -1) {
outputStream.write(buffer, 0, bytesRead);
}
outputStream.close();
inputStream.close();

6. 使用Apache Commons IO庫下載文件：

URL url = new URL(fileUrl);
FileUtils.copyURLToFile(url, new File(savePath));

請注意，以上代碼可能需要處理異常或添加進一步的邏輯來完善下載過程。