REGEXVAULTv2.0
Dev & Systems/SemVer
Verified Safe

SemVer Pre-Release Identifier Regex for Java

/^(?:0|[1-9][0-9]*|[0-9]*[a-zA-Z][a-zA-Z0-9\-]*)(?:\.(?:0|[1-9][0-9]*|[0-9]*[a-zA-Z][a-zA-Z0-9\-]*))*$/

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching semver pre-release identifier, ported and verified for Java. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your Java project — whether you're validating in a Spring Boot controller, a Jakarta EE service, or a standalone utility class.

Java Implementation

Java
// SemVer Pre-Release Identifier
// ReDoS-safe | RegexVault — Dev & Systems > SemVer

import java.util.regex.Pattern;

public class SemverPrereleaseIdentifierValidator {
    private static final Pattern PATTERN =
        Pattern.compile("^(?:0|[1-9][0-9]*|[0-9]*[a-zA-Z][a-zA-Z0-9\\-]*)(?:\\.(?:0|[1-9][0-9]*|[0-9]*[a-zA-Z][a-zA-Z0-9\\-]*))*$");

    public static boolean validate(String input) {
        return PATTERN.matcher(input).matches();
    }

    // Example
    public static void main(String[] args) {
        System.out.println(validate("alpha")); // true
    }
}

Test Cases

Matches (Valid)
Rejects (Invalid)
alpha-alpha
alpha.1alpha.
0.3.7.alpha
x.7.z.9201
betaalpha..beta
rc.1
SNAPSHOT

When to use this pattern

This pattern is drawn from the Dev & Systems > SemVer category and carries a ReDoS-safe certification. That matters for Java developers because critical in Java applications since the JVM regex engine uses backtracking and is susceptible to ReDoS without careful pattern design. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

SemVer pre-release ordering: 1.0.0-alpha < 1.0.0-alpha.1 < 1.0.0-alpha.beta < 1.0.0-beta < 1.0.0-rc.1 < 1.0.0.

Technical Notes

Numeric identifiers must not have leading zeros (01 is invalid). Alphanumeric identifiers have lower precedence than numeric ones in version comparison.

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