For those of you who are familiar with Regular expressions in Perl PHP or Tcl, and wonder what they look like in the latest release of Java, here's an example.

You create a Pattern object using the compile method on your regular expression, then you use the matcher method to create a Matcher object. Finally, the fit method on that object will give you a boolean result telling you whether or not the match was sucessful.

May sound a bit complex, but by splitting the operation down into compile, match and give result, your program can be saved the need to do lots of repeated work as it would in languages which do all the steps at once.  It's an interesting discussion as to whether or not you need that extra run time performance ...

Code:

import java.util.regex.*;  public class Reg1 {  public static void main (String [] args) {                  Pattern email = Pattern.compile("^\\S+@\\S+$");                  for (int i=0; i<args.length; i++) {                          Matcher fit = email.matcher(args[i]);                          if (fit.matches()) {                                  System.out.println (                                  "\"" +args[i] +                                  "\" IS a possible email address");                          } else {                                  System.out.println (                                  "\"" + args[i] +                                  "\" is NOT an email address");                          }                  }          }  }

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