Validate PCRE in Java

Question

Given a string, how can I validate the contents are a valid PCRE within Java? I don't want to use the regex in any way within Java, just validate its contents.

java.util.regex.Pattern is almost good enough, but its javadoc points out how it differs from Perl.

In detail, there's a system with 3 relevant components:

1. Component A - Generates, among other things, Perl-compliant regular expressions (PCREs) to be evaluated at runtime by some other component capable of executing PCREs (component C). What's "generated" here may be coming from a human.
2. Component B - Validates that data generated by component A and, if valid, shuttles it over to the runtime (component C).
3. Component C - Some runtime that evaluates PCREs. This could be a Perl VM, a native process using the PCRE library, Boost.Regex, etc., or something else that can compile/execute a Perl-compliant regular expression.

Now, component B is implemented in Java. As mentioned above, it needs to validate a string potentially containing a PCRE, but does not need to execute it.

How could we do that?

One option would be something like:

public static boolean isValidPCRE(String str) {
    try {
        Pattern.compile(str);
    } catch (PatternSyntaxException e) {
        return false;
    }

    return true;
}

The problem is that java.util.regex.Pattern is designed to work with a regular expression syntax that is not exactly Perl-compliant. The javadoc makes that quite clear.

So, given a string, how can I validate the contents are a valid PCRE within Java?

Note: There are some differences between libPCRE and Perl, but they are pretty minor. To a certain degree, that is true of Java's syntax as well. However, the question still stands.