Git Commit Hash (SHA-256, New Format) Regex for Java
/^[0-9a-fA-F]{64}$/What this pattern does
This page provides a lightweight, single-purpose regular expression for matching git commit hash (sha-256, new format), ported and verified for Java. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your Java project — whether you're validating in a Spring Boot controller, a Jakarta EE service, or a standalone utility class.
Java Implementation
// Git Commit Hash (SHA-256, New Format)
// ReDoS-safe | RegexVault — Dev & Systems > Git
import java.util.regex.Pattern;
public class GitCommitHashSha256NewFormatValidator {
private static final Pattern PATTERN =
Pattern.compile("^[0-9a-fA-F]{64}$");
public static boolean validate(String input) {
return PATTERN.matcher(input).matches();
}
// Example
public static void main(String[] args) {
System.out.println(validate("e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")); // true
}
}Test Cases
Matches (Valid) | Rejects (Invalid) |
|---|---|
e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855 | a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0 |
0000000000000000000000000000000000000000000000000000000000000000 | e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855zzz |
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff | short |
| — | — |
When to use this pattern
This pattern is drawn from the Dev & Systems > Git 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
A 64-char hex string could also be a Docker digest or other SHA-256 hash. Use context to confirm it is a Git hash.
Technical Notes
Git SHA-256 (Object Format Version 1) was introduced experimentally. SHA-256 repositories are not yet fully interoperable with SHA-1 repositories as of 2026.
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