Are regex engines of Java and Groovy the same?

Question

Now I am doing some code basing on regex in Groovy. But for creation and testing my regexes I use books referencing to Java regex engine and Java-oriented http://www.regexplanet.com/advanced/java/index.html.

And I am a bit afraid - Is Groovy regex engine really the same as Java one? I know that they are very close. But have they some differences nevertheless? If you know the answer - can you kindly give me some reference on the subject?

Answer 1

From the language documentation:

The pattern operator (~) provides a simple way to create a java.util.regex.Pattern instance.

I can't find phrasing where the documentation guarantees this is the regular expression engine used for pattern matching throughout Groovy; I do however find it very, very, very, very unlikely Groovy would use two RE engines in its implementation now or switch the RE engine in the future.

Answer 2

"Because Groovy is based on Java, you can use Java's regular expression package with Groovy. Simply put import java.util.regex.* at the top of your Groovy source code. Any Java code using regular expressions will then automatically work in your Groovy code too." Source: regular-expressions.info