• Use regex asserts for testing your application
  • with the sun java 1.4 regex implementation
  • with Jakarta Regexp
  • with the regex implementation you want
• Run test files for the regex implementation

• Jakarta Regexp at http://jakarta.apache.org/regexp/
• Jakarta Oro at http://jakarta.apache.org/oro/
• Gnu Regexp at http://www.cacas.org/java/gnu/regexp/

• Use regex asserts for your application
• Running test files for the regex implementation
  • Run your own testfiles
  • Run the Jakarta Regexp tests "docs/RETest.txt"
  • Run other implementation tests

• Regular Expressions and the Java Programming Language
• Using Regular Expression Groups

Using Regular Expression Groups

• JakartaRegexp at http://jakarta.apache.org/regexp/
• JakartaOro at http://jakarta.apache.org/oro/
• GnuRegexp at http://www.cacas.org/java/gnu/regexp/

• JRegex at http://jregex.sourceforge.net/

RegularExpressions

Regular expressions are common in many programming languages and Unixish utilities and provide a way to describe the format of text strings. You can write a pattern and then see if a string matches it, or look for all matches, or replace them all with something else, and so on. Here is an example of a regular expression matching typical (but not all) HTTP URLs with optional query strings and fragments:

http://([a-z0-9-]+\.)+[a-z0-9-]+/[^\s#?]*(\?[^\s?#)+?(#[^\s?#)+?

J2SE 1.4 supports regular expressions natively in the java.util.regex package. For earlier versions of Java, or for more choices, you can use:

• JakartaRegexp^? at http://jakarta.apache.org/regexp/
• JakartaOro^? at http://jakarta.apache.org/oro/
• GnuRegexp^? at http://www.cacas.org/java/gnu/regexp/

Mastering Regular Expressions at http://www.oreilly.com/catalog/regex2/ is a good introduction and covers advanced usage, including Java (this chapter is available online).

Discussion about RegularExpressions