Regular Expressions - Beginning Java 8 Fundamentals - page 520

public static void findPattern(String regex, String source) {
// Compile regex into a Pattern object
Pattern p = Pattern.compile(regex);
// Get a Matcher object
Matcher m = p.matcher(source);
// Print regex and source text
System.out.println("\nRegex:" + regex);
System.out.println("Text:" + source);
// Perform find
boolean found = false;
while (m.find()) {
System.out.println("Matched Text:" + m.group() +
", Start:" + m.start() +
", " + "End:" + m.end());
// We found at least one match. Set the found flag to true
found = true;
}
if (!found) {
// We did not find any match
System.out.println("No match found");
}
}
}
Regex:[abc]@.
Text:[e-mail] is a valid email address
Matched Text:c@j, Start:3, End:6
Regex:[abc]@.
Text:[e-mail] is invalid
No match found
Regex:[abc]@.
Text:a@band@yea@u
Matched Text:a@b, Start:0, End:3
Matched Text:a@u, Start:9, End:12
Regex:[abc]@.
Text:There is an @ sign here
No match found