hibernate/hibernate-orm · error · IllegalArgumentException

Entity may not be null

Error message

Entity may not be null

What it means

Error "Entity may not be null" thrown in hibernate/hibernate-orm.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/internal/SessionImpl.java:1625

							uee.getMessage()
								+ " ('" + entityClass.getSimpleName() + "' " + problem + ")",
							e
					);
				}
			}
		}
	}

	// not for internal use:

	@Override
	@Nullable
	public Object getIdentifier(@Nonnull Object object) {
		checkOpen();
		checkTransactionSyncStatus();
		//noinspection ConstantValue
		if ( object == null ) {
			throw new IllegalArgumentException( "Entity may not be null" );
		}
		final var lazyInitializer = extractLazyInitializer( object );
		if ( lazyInitializer != null ) {
			checkOwnsProxy( lazyInitializer );
			return lazyInitializer.getInternalIdentifier();
		}
		else {
			return getEntityEntry( object ).getId();
		}
	}

	/**
	 * Get the id value for an object that is actually associated with the session.
	 * This is a bit stricter than
	 * {@link org.hibernate.engine.internal.ForeignKeys#getEntityIdentifierIfNotUnsaved}.
	 */
	@Override
	public Object getContextEntityIdentifier(@Nonnull Object object) {

View on GitHub (pinned to fad1729dce)

Solutions

1. Pass a non-null entity instance to the Session operation; null-check the object before calling persist/merge/remove/etc.
2. If the entity may legitimately be absent, guard the call with an Optional or explicit if (entity != null).

When it happens

Trigger: Thrown at hibernate-core/src/main/java/org/hibernate/internal/SessionImpl.java:1625 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/9b3ae3b9e89a72cb. Report an issue: GitHub.