자바에서 파일을 복사하는 4가지 방법

1. FileStream

private static void copyFileUsingFileStreams(File source, File dest)
		throws IOException {
	InputStream input = null;
	OutputStream output = null;
	try {
		input = new FileInputStream(source);
		output = new FileOutputStream(dest);
		byte[] buf = new byte[1024];
		int bytesRead;
		while ((bytesRead = input.read(buf)) > 0) {
			output.write(buf, 0, bytesRead);
		}
	} finally {
		input.close();
		output.close();
	}
}

2. java.nio.channels.FileChannel

private static void copyFileUsingFileChannels(File source, File dest)
		throws IOException {
	FileChannel inputChannel = null;
	FileChannel outputChannel = null;
	try {
		inputChannel = new FileInputStream(source).getChannel();
		outputChannel = new FileOutputStream(dest).getChannel();
		outputChannel.transferFrom(inputChannel, 0, inputChannel.size());
	} finally {
		inputChannel.close();
		outputChannel.close();
	}
}

3. Apache Commons IO

private static void copyFileUsingApacheCommonsIO(File source, File dest)
		throws IOException {
	FileUtils.copyFile(source, dest);
}

4. Java 7 Files class

private static void copyFileUsingJava7Files(File source, File dest)
		throws IOException {
	Files.copy(source.toPath(), dest.toPath());
}

[출처] 4 Ways to Copy File in Java