apache/iceberg · error · IllegalArgumentException

Provided implementation for dynamic instantiation should…

Error message

Provided implementation for dynamic instantiation should implement %s.

What it means

After reflective construction, the instantiated object is cast to LocationProvider; a ClassCastException means the configured class loaded and constructed but does not implement LocationProvider, so locationsFor rejects it with this IllegalArgumentException.

Solutions

1. Make the configured class implement org.apache.iceberg.LocationProvider
2. Rebuild against the Iceberg version in use so the interface matches
3. Point write.location-provider.impl at a built-in provider or a correct custom implementation

Example fix

// before
class MyProvider { public MyProvider(String l, Map<String,String> p) {} }
// after
class MyProvider implements LocationProvider {
  public MyProvider(String location, Map<String, String> properties) { ... }
  @Override public String newDataLocation(String fileName) { ... }
}

Class<?> c = Class.forName(implName);
if (!LocationProvider.class.isAssignableFrom(c)) {
  throw new IllegalStateException(implName + " must implement LocationProvider");
}

LocationProvider.class.isAssignableFrom(clazz)

try {
  LocationProviders.locationsFor(location, props);
} catch (IllegalArgumentException e) {
  LOG.error("Impl does not implement LocationProvider: {}", implName, e);
}

When it happens

Trigger: Setting write.location-provider.impl to a class that constructs successfully via a matching constructor signature but does not implement org.apache.iceberg.view.LocationProvider/org.apache.iceberg.LocationProvider (e.g., implements a different interface or none).

Common situations: Copying a provider implementation from another library or older Iceberg version with a different interface; generic-purpose class reused accidentally as location provider.

Understand the failure class

Background: Type mismatch errors: IllegalArgumentException, TypeError and type guards across 150 open-source libraries — this error's family across 150 libraries.

Related errors

• Cannot initialize AdlsTokenCredentialProvider
• Cannot initialize DellClientFactory
• Cannot initialize TLSConfigurer
• Unable to find a constructor for implementation
• Cannot convert dict encoded field

AI-assisted analysis of apache/iceberg@86d9c8fc54 (2026-09-12). Data as JSON: /api/errors/558125b70a2b7caa. Report an issue: GitHub.

Appendix: source

Thrown at core/src/main/java/org/apache/iceberg/LocationProviders.java:64

        ctor =
            DynConstructors.builder(LocationProvider.class)
                .impl(impl, String.class, Map.class)
                .impl(impl)
                .buildChecked(); // fall back to no-arg constructor
      } catch (NoSuchMethodException e) {
        throw new IllegalArgumentException(
            String.format(
                "Unable to find a constructor for implementation %s of %s. "
                    + "Make sure the implementation is in classpath, and that it either "
                    + "has a public no-arg constructor or a two-arg constructor "
                    + "taking in the string base table location and its property string map.",
                impl, LocationProvider.class),
            e);
      }
      try {
        return ctor.newInstance(location, properties);
      } catch (ClassCastException e) {
        throw new IllegalArgumentException(
            String.format(
                "Provided implementation for dynamic instantiation should implement %s.",
                LocationProvider.class),
            e);
      }
    } else if (PropertyUtil.propertyAsBoolean(
        properties,
        TableProperties.OBJECT_STORE_ENABLED,
        TableProperties.OBJECT_STORE_ENABLED_DEFAULT)) {
      return new ObjectStoreLocationProvider(location, properties);
    } else {
      return new DefaultLocationProvider(location, properties);
    }
  }

  private static final Set<String> DEPRECATED_PROPERTIES =
      ImmutableSet.of(
          TableProperties.OBJECT_STORE_PATH, TableProperties.WRITE_FOLDER_STORAGE_LOCATION);

View on GitHub (pinned to 86d9c8fc54)