Java文件流傳輸主要有以下幾種方法：

1. 字節流傳輸：使用InputStream和OutputStream進行字節流傳輸。可以使用InputStream讀取源文件的字節數據，然后使用OutputStream將字節數據寫入目標文件。

// 讀取源文件的字節數據
InputStream inputStream = new FileInputStream("source.txt");
byte[] buffer = new byte[1024];
int bytesRead;
while ((bytesRead = inputStream.read(buffer)) != -1) {
    // 將字節數據寫入目標文件
    outputStream.write(buffer, 0, bytesRead);
}
inputStream.close();
outputStream.close();

2. 字符流傳輸：使用Reader和Writer進行字符流傳輸。可以使用Reader讀取源文件的字符數據，然后使用Writer將字符數據寫入目標文件。

// 讀取源文件的字符數據
Reader reader = new FileReader("source.txt");
char[] buffer = new char[1024];
int charsRead;
while ((charsRead = reader.read(buffer)) != -1) {
    // 將字符數據寫入目標文件
    writer.write(buffer, 0, charsRead);
}
reader.close();
writer.close();

3. 緩沖流傳輸：使用BufferedInputStream和BufferedOutputStream進行字節流傳輸，或使用BufferedReader和BufferedWriter進行字符流傳輸。緩沖流可以提高讀寫效率，適用于大文件傳輸。

// 使用字節流傳輸
InputStream inputStream = new FileInputStream("source.txt");
OutputStream outputStream = new FileOutputStream("target.txt");
BufferedInputStream bufferedInputStream = new BufferedInputStream(inputStream);
BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(outputStream);
byte[] buffer = new byte[1024];
int bytesRead;
while ((bytesRead = bufferedInputStream.read(buffer)) != -1) {
    bufferedOutputStream.write(buffer, 0, bytesRead);
}
bufferedInputStream.close();
bufferedOutputStream.close();

// 使用字符流傳輸
Reader reader = new FileReader("source.txt");
Writer writer = new FileWriter("target.txt");
BufferedReader bufferedReader = new BufferedReader(reader);
BufferedWriter bufferedWriter = new BufferedWriter(writer);
char[] buffer = new char[1024];
int charsRead;
while ((charsRead = bufferedReader.read(buffer)) != -1) {
    bufferedWriter.write(buffer, 0, charsRead);
}
bufferedReader.close();
bufferedWriter.close();

這些方法可以根據具體的需求選擇適合的方式進行文件傳輸。