Java是一種非常強(qiáng)大的編程語(yǔ)言，可以輕松實(shí)現(xiàn)各種功能。其中一個(gè)非常常見(jiàn)的功能就是上傳和下載文件。下面我們就來(lái)介紹一下Java如何實(shí)現(xiàn)上傳和下載。

上傳文件

public void uploadFile(String url, String filePath) {
try {
URL uploadUrl = new URL(url);
HttpURLConnection connection = (HttpURLConnection) uploadUrl.openConnection();
connection.setDoOutput(true);
connection.setRequestMethod("POST");
File file = new File(filePath);
FileInputStream fileInputStream = new FileInputStream(file);
OutputStream outputStream = connection.getOutputStream();
byte[] buffer = new byte[4096];
int bytesRead = -1;
while ((bytesRead = fileInputStream.read(buffer)) != -1) {
outputStream.write(buffer, 0, bytesRead);
}
outputStream.close();
fileInputStream.close();
int responseCode = connection.getResponseCode();
System.out.println("Response Code: " + responseCode);
} catch (Exception e) {
e.printStackTrace();
}
}

下載文件

public void downloadFile(String url, String saveFilePath) {
try {
URL downloadUrl = new URL(url);
HttpURLConnection connection = (HttpURLConnection) downloadUrl.openConnection();
connection.setRequestMethod("GET");
int responseCode = connection.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_OK) {
InputStream inputStream = connection.getInputStream();
byte[] buffer = new byte[4096];
int bytesRead = -1;
File file = new File(saveFilePath);
FileOutputStream fileOutputStream = new FileOutputStream(file);
while ((bytesRead = inputStream.read(buffer)) != -1) {
fileOutputStream.write(buffer, 0, bytesRead);
}
fileOutputStream.close();
inputStream.close();
System.out.println("File downloaded: " + saveFilePath);
} else {
System.out.println("Download failed");
}
} catch (Exception e) {
e.printStackTrace();
}
}

以上就是Java實(shí)現(xiàn)上傳和下載的基本代碼示例。當(dāng)然在實(shí)際開(kāi)發(fā)中，還需要考慮一些其他的情況，例如上傳文件大小、下載進(jìn)度顯示等等。希望這篇文章能夠幫助到需要實(shí)現(xiàn)上傳和下載功能的開(kāi)發(fā)者們。