How to use PCRE2 in Java?

Java does not use PCRE or PCRE2 internally.
Java’s regex engine (java.util.regex) is its own implementation and is not PCRE-compatible.

If you need PCRE2-specific features (such as certain backtracking control verbs, advanced lookbehinds, or full PCRE syntax compatibility), you have a few options:

1. Use Java’s Built-in Regex (If PCRE2 Features Are Not Required)

For most use cases:

import java.util.regex.*; Pattern pattern = Pattern.compile("\\d+"); Matcher matcher = pattern.matcher("123 abc"); while (matcher.find()) { System.out.println(matcher.group()); }

If your pattern works with Java’s engine, no external library is needed.

2. Use PCRE2 via JNI (Native Binding)

PCRE2 is a C library. To use it directly in Java, you must:

Compile PCRE2 as a native library.

Create JNI bindings.

Load it using System.loadLibrary().

This is complex and usually unnecessary unless you require exact PCRE2 behavior.

3. Use a Java Library That Wraps PCRE

There are third-party libraries that provide PCRE compatibility via JNI bindings. Example:

com.github.florianingerl.util.regex (PCRE-like behavior)

JPCRE2 (JNI wrapper around PCRE2)

Example (with a PCRE wrapper library):

Pattern pattern = Pattern.compile("(?<=\\d{2})abc");

Note: Library setup depends on the specific wrapper used.

4. Use GraalVM (Advanced Option)

If running on GraalVM, you can access PCRE-compatible regex engines via Truffle/Polyglot APIs. This is an advanced setup and not typical for standard Java applications.

---

Important Considerations

Java regex is similar to PCRE but not identical.

Some PCRE2 features (e.g., (*SKIP)(*FAIL)) are not supported in standard Java.

Native bindings introduce platform dependency.

For portability, prefer Java’s built-in regex engine unless strict PCRE2 compliance is required.

---

Summary

You cannot directly use PCRE2 in standard Java.
You must either:

Use Java’s built-in regex engine

Use a JNI wrapper around PCRE2

Use a third-party compatibility library

The appropriate choice depends on whether you truly need PCRE2-specific features.