Added in API level 1

java.util.regex

Classes for matching character sequences against patterns specified by regular expressions.

An instance of the Pattern class represents a regular expression that is specified in string form in a syntax similar to that used by Perl.

Instances of the Matcher class are used to match character sequences against a given pattern. Input is provided to matchers via the CharSequence interface in order to support matching against characters from a wide variety of input sources.

Unless otherwise noted, passing a null argument to a method in any class or interface in this package will cause a NullPointerException to be thrown.

An excellent tutorial and overview of regular expressions is Mastering Regular Expressions, Jeffrey E. F. Friedl, O'Reilly and Associates, 1997.

Interfaces

Classes

Matcher An engine that performs match operations on a character sequence by interpreting a Pattern. 
Pattern A compiled representation of a regular expression. 

Exceptions