1、 IO包中的类层次
┌BufferedInputStream
├DataInputStream
┌FilterInputStream┼LineNumberInputStream
├FileInputStream └PushbackInputStream
├ByteArrayInputStream
┌InputStream──┼PipedInputStream
│ ├SequenceInputStream
│ ├StringBufferInputStream
│ └ObjectInputStream ┌BufferedOutputStream
│ ┌FilterOutputStream┼DataOutputStream
Object┤ ├FileOutputStream └PrintStream
├OutputStream──┼ByteArrayOutputStream
├File ├PipedOutputStream
├FileDescriptor └ObjectOutputStream
├ObjdecStreamClass
├RandomAccessFile
└StreamTokenizer
Reader InputStream
├BufferedReader BufferedInputStream
│ └LineNumberReader LineNumberReader
├CharArrayReader ByteArrayInputStream
├InputStreamReader (none)
│ └FileReader FileInputStream
├FilterReader FilterInputStream
│ └PushbackReader PushbackInputStream
├PipedReader PipedInputStream
└StringReader StringBufferInputStream
Write OutputStream
├BufferedWriter BufferedOutputStream
├CharArrayWriter ByteArrayOutputStream
├OutputStreamWriter (none)
│ └FileWriter FileOutputStream
├FilterWriter FilterOutputStream
├PrintWriter PrintStream
├PipedWriter PipedOutputStream
└StringWriter (none)