???????? ---> ??????? ----> ??????? ---> ???
???????????? -- see p273 ??????
???????????? --
???????????????
????DataOutputStream(OutputStream out) //??OutputStream????DataOutputStream
????BufferedInputStream ?? BufferOutputStream
????---??????????IO???л???
??????????????????и???????
????????????
????BufferedInputStream(InputStream in)
???????????????32???????????????
????BufferedInputStream(InputStream in?? int size)
???????????????????????С???????
????BufferedOutputStream(OutputStream out)
????????????μ??????????????????д????????????????
????BufferedOutputStream(OutputStream out?? int size)
????????????μ?????????????????????????????С??????д????????????????
????DataInputStream ?? DataOutputStream
????———— ??????д??????????????????????????
????DataOutputStream????3??д??????????????
????1. writeBytes(String s)
????2. writeChars(String s)
????3. writeUTF(Strng s)
????PrintStream??
???????????е?print??println???????????????????????????????????????????
????????????
????PrintStream(OutputStream out)
????PrintStream(OutputStream out?? boolean autoflush)
????PrintStream(OutputStream out?? boolean autoflush?? String encoding)
????autoflush????java?????????з??? ?????????????????
????Java??PrintStream??????ж???????Print??Println????
??????Windows??????????? “ ”  ??Linux?μ??????????“ ”
????PrintWriter??println?????????????????????????????з?
????PrintWriter?? -- ??PrintStream????
??????????????autoFlush?? ??????????println????????????????????
????ObjectInputStream ?? ObjectOutputStream
????????洢????????????????????