java.io
Interfaces 
Closeable
DataInput
DataOutput
FileFilter
FilenameFilter
Flushable
ObjectInput
ObjectOutput
ObjectStreamConstants
Serializable
Classes 
BufferedReader
BufferedWriter
ByteArrayOutputStream
File
FileDescriptor
FileSystem
FileWriter
FilterOutputStream
InputStream
ObjectInputStream
ObjectOutputStream
ObjectStreamField
OutputStream
OutputStreamWriter
PrintStream
PrintWriter
RandomAccessFile
Reader
Writer
Exceptions 
FileNotFoundException
IOException
ObjectStreamException
StreamCorruptedException
UnsupportedEncodingException