Java equivalent of Perl's s/// operator?

Question

I have some code that I'm converting from Perl to Java. It makes pretty heavy use of regular expressions, including the s/// operator. I've been using Perl for a long time and am still getting used to the Java way of doing things. In particular, Strings seem more difficult to work with. Does anyone know of or have a Java function that fully implements s///? So that it could handle something like this, for example:

$newString =~ s/(\bi'?\b)/\U$1/g;

(Maybe not a great example, but you get the idea.) Thanks.

Answer 1

Have a look at String's replaceAll(...) method. Note that Java does not support the \U (upper-case) feature.

Answer 2

Nothing so tidy, but in Java you would use String.replaceAll() or use Pattern to do something like:

Pattern p = Pattern.compile("(\bi'?\b)");

Matcher m = p.matcher(stringToReplace);
m.replaceAll("$1");

Check the Pattern docs for Java's regex syntax--it doesn't overlap completely with Perl.

---

To get uppercasing, check out Matcher.appendReplacement:

StringBuffer sb = new StringBuffer();
while (m.find()) {
    String uppercaseGroup = m.group(1).toUpperCase();
    m.appendReplacement(sb, uppercaseGroup);
}
m.appendTail();

Not as close to Perl as the jakarta-oro library referenced above, but definitely some help built into the library.

Answer 3

Given an instance of a String class you can use the .replaceAll() method like so:

String A = "Test";
A.replaceAll("(\bi'?\b)","\U$1");

Edit - ok too slow. Also apparently \U isn't supported according to another answer.

Note - I'm not sure how the greedy symbol translates, you might want to try looking into Java's implementation if you need that specifically.