用IO流复制文本内容到另一个文本中

//将文本 abc.txt 里面的内容复制给文本 abdd.txt

FileInputStream fis = new FileInputStream("abc.txt"); //readLine() 只读了一行
BufferedReader br = new BufferedReader(new InputStreamReader(fis));

PrintWriter pw = new PrintWriter("abdd.txt");
String bb = null;

while((bb = br.readLine())!= null) {
pw.print(bb);
}
br.close();
pw.close();