字节流
InputStream
FileInputStream
FilterInputStream
BufferedInputStream
DataInputStream
PushbackInputStream
ObjectInputStream
PipedInputStream
ByteArrayInputStream
StringBufferInputStream
SequenceInputStream
OutputStream
FileOutputStream
FilterOutputStream
BufferedOutputStream
DataOutputStream
PrintStream
ObjectOutputStream
PipedOutputStream
ByteArrayOutputStream
字符流
Reader
BufferedReader
InputStreamReader
FileReader
StringReader
PipedReader
ByteArrayReader
FilterReader
PushbackReader
Writer
BufferedWriter
OutputStreamWriter
FileWriter
PrinterWriter
StringWriter
PipedWriter
CharArrayWriter
FilterWriter