BufferedInputStream 和 BufferedOutputStream

  一般打开(in/out)文件, 都加上缓冲流, 提高IO性能

             DOS      BOS     FOS

  应用程序 -- 过滤器-->过滤器-->输出流--> 文件(Byte)

      writeInt(i)    write() write(byte[]) ff ff ff fd

                      byte[]

  FileInputStream fis = new FileInputStream(file);

  BufferedInputStream bis = new BufferedInputStream(fis);

  DataInputStream in = new DataInputStream(bis);

  FileOutputStream fos = new FileOutputStream(file);

  BufferedOutputStream bos = new BufferedOutputStream(fos);

  DataOutputStream out = new DataOutputStream(bos);