Runtime Diagnostics
Java SSLHandshakeException Debugging Guide
Diagnose Java SSLHandshakeException failures across certificate chains, hostnames, protocols, trust stores and mutual TLS without disabling verification. This reference is written for developers who need practical validation behavior, reviewable rules and safe examples rather than copied snippets with no explanation.
Recommended workflow
| Step | Why it matters |
|---|---|
| Capture the exact cause | Separate certificate-path, hostname, protocol, cipher and client-certificate failures. |
| Inspect the endpoint | Use SNI-aware certificate checks and compare the served chain with the Java error. |
| Confirm the runtime trust store | Identify the exact JDK, configured trustStore and container image used by the failing process. |
| Test the narrow fix | Add the required CA or correct the server chain, then retest with verification enabled. |
Starter snippet
java -Djavax.net.debug=ssl,handshake -jar app.jarReview checks
- Redact tokens and session data from SSL debug logs.
- Check JVM and system clocks.
- Prefer public or managed CA chains when possible.
- Document custom trust-store ownership and rotation.
Common mistakes
- Installing a permissive TrustManager.
- Importing the leaf certificate as a permanent trust anchor.
- Testing with a different JDK than production.
Validation should help users correct input while protecting systems from bad data. Keep syntax checks, product policy, security review and deliverability checks separate.
Related Formalint references
Continue with TLS Certificate Chain Debugging, Java Runtime Guide, Java Classpath Debugging Guide.