提升文件的读写效率--缓冲流

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();