Classes helping in parsing the input

Some of the classes in the Java IO API are designed to help you parse input. These classes are:

• PusbackInputStream
  
• StreamTokenizer
  
• PushbackReader
  
• LineNumberReader
  

It is not the purpose of this text to give you a complete course in parsing of data. The purpose was rather to give you above quick list of classes related to parsing of input data.
If you have to parse data you will often end up writing your own classes that use some of the classes in this list. I know I did when I wrote the parser for the Butterfly Container Script. I used the PushbackInputStream at the core of my parser, because sometimes I needed to read ahead a character or two, to determine what the character at hand meant.