BufferedReader br = new BufferedReader(new FileReader("readme.txt"));
BufferedWriter bw = new BufferedWriter(new FileWriter("dest.txt"));
char[] chs = new char[2048];
int len;
while((len = br.read(chs)) != -1) {
bw.write(chs);
}
bw.flush();//记得刷新缓冲流
br.close();
bw.close();