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Stack trace explainer

Paste a Java exception with its stack trace. It finds the root cause, the first frame in your code, and the checks worth making for common Spring and JVM failures.

Paste the full trace, including any "Caused by" lines.

Root cause

org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: dev.example.Policy.coverages, could not initialize proxy - no Session

Likely cause

Lazy association read outside a session

A lazily loaded relationship was accessed after its Hibernate session or transaction had closed.

First frame in application code

dev.example.policy.PolicySummaryService.summarize (PolicySummaryService.java:42)

Check these

  • Load it inside the transaction: put @Transactional on the service method that reads it.
  • Or fetch it explicitly with @EntityGraph or JOIN FETCH.
  • Map to a DTO inside the transaction rather than returning entities to the web layer.

Exception chain

  1. org.springframework.dao.InvalidDataAccessApiUsageException
  2. Caused by: org.hibernate.LazyInitializationException

Rule-based, not AI: it matches known exception types and says so when nothing matches. Runs entirely in your browser; the trace is not sent or stored.