java File獲取字節流

/*文件64位編碼*/
public static void main(String[] args) {
byte[] fileByte = toByteArray(newFile);
String imgStr = new BASE64Encoder().encode(fileByte);
}

/*讀取文件的字節數組*/
public static byte[] toByteArray(File file) throws IOException {
File f = file;
if (!f.exists()) {
throw new FileNotFoundException("file not exists");
}
ByteArrayOutputStream bos = new ByteArrayOutputStream((int) f.length());
BufferedInputStream in = null;
try {
in = new BufferedInputStream(new FileInputStream(f));
int buf_size = 1024;
byte[] buffer = new byte[buf_size];
int len = 0;
while (-1 != (len = in.read(buffer, 0, buf_size))) {
bos.write(buffer, 0, len);
}
return bos.toByteArray();
} catch (IOException e) {
e.printStackTrace();
throw e;
} finally {
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
bos.close();
}
}