hibernate/hibernate-orm · error · StrategySelectionException

Unable to resolve name [{}] as strategy [{}]

Error message

Unable to resolve name [{}] as strategy [{}]

What it means

selectStrategyImplementor(strategy, name) resolves a strategy in three steps: registered short names, the strategy's lazy resolver if one exists, and finally classForName(name). When all fail, the ClassLoadingException is wrapped as StrategySelectionException 'Unable to resolve name [...] as strategy [...]' - the name is neither a registered strategy name nor a loadable class name.

Source

Thrown at hibernate-core/src/main/java/org/hibernate/boot/registry/selector/internal/StrategySelectorImpl.java:81

			final var registered = namedStrategyImplementorMap.get( name );
			if ( registered != null ) {
				return (Class<T>) registered;
			}
		}

		final var lazyServiceResolver = lazyStrategyImplementorByStrategyMap.get( strategy );
		if ( lazyServiceResolver != null ) {
			final var resolve = lazyServiceResolver.resolve( name );
			if ( resolve != null ) {
				return (Class<? extends T>) resolve;
			}
		}

		try {
			return classLoaderService.classForName( name );
		}
		catch (ClassLoadingException e) {
			throw new StrategySelectionException(
					"Unable to resolve name [" + name + "] as strategy [" + strategy.getName() + "]",
					e
			);
		}
	}

	@Override
	public <T> T resolveStrategy(Class<T> strategy, Object strategyReference) {
		return resolveDefaultableStrategy( strategy, strategyReference, (T) null );
	}

	@Override
	public <T> T resolveDefaultableStrategy(Class<T> strategy, Object strategyReference, final T defaultValue) {
		return resolveDefaultableStrategy(
				strategy,
				strategyReference,
				(Callable<T>) () -> defaultValue
		);

View on GitHub (pinned to fad1729dce)

Solutions

1. Use the fully-qualified class name of an existing implementation, or a currently registered short name
2. After a Hibernate 5 to 6 upgrade, replace removed versioned dialect aliases with the un-versioned family dialect (e.g. org.hibernate.dialect.MySQLDialect)
3. Verify the class is on the runtime classpath and the property value has no trailing whitespace or quote characters

Example fix

// before
<property name="hibernate.dialect" value="MySQL57Dialect"/> <!-- alias removed in 6.x -->

// after
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect"/>

// Validate strategy names before boot
String dialect = config.get("hibernate.dialect");
try {
    Class.forName(dialect); // or check against a whitelist of known short names
} catch (ClassNotFoundException e) {
    throw new IllegalStateException("Unknown dialect name: " + dialect, e);
}

try {
    Class<? extends Dialect> d = strategySelector.selectStrategyImplementor(Dialect.class, name);
} catch (StrategySelectionException e) {
    // e.getCause() is a ClassLoadingException: name is neither registered nor loadable
    // fall back to the FQN of a known-good dialect
    return org.hibernate.dialect.PostgreSQLDialect.class;
}

When it happens

Trigger: Setting a strategy by name where the name is wrong: hibernate.dialect=my.Dialect that does not exist, a Hibernate 5 dialect alias removed in Hibernate 6, jta.platform short names, or a property value carrying whitespace/quotes.

Common situations: Upgrading Hibernate 5 to 6 where versioned dialect shorthands (e.g. MySQL57Dialect) were removed in favor of family dialects; typos in class names; missing jar containing the custom strategy class; quoted property values in YAML/XML.

Related errors

• Default resolver threw exception
• Cannot instantiate the class [{}] because it does not have a
• Unable to load class [" + className + "]
• Unknown TcclLookupPrecedence - {}
• Can't use this method on for strategy types which are embedd

AI-assisted analysis of hibernate/hibernate-orm@fad1729dce (2026-08-22). Data as JSON: /api/errors/55f8779889e49316. Report an issue: GitHub.