AsyncWaitStrategyFactoryConfig - potential NPE when creating programatically

[JWT007]

AsyncWaitStrategyFactoryConfig (Log4j 2.24.1)

This @Plugin doesn't behave like most others where if the configuration is invalid, it will return a null from the Builder.

The @PluginBuilderAttribute factoryClassName (for the XML class attribute) is marked as @Required, but if creating programatically the missing value is not checked and the constructor will throw a NPE.

@Override
public AsyncWaitStrategyFactoryConfig build() {
    return new AsyncWaitStrategyFactoryConfig(factoryClassName);
}

public AsyncWaitStrategyFactoryConfig(final String factoryClassName) {
    this.factoryClassName = Objects.requireNonNull(factoryClassName, "factoryClassName");
}

Typical behaviour here would be to return null from the build() method if misconfigured.

• adding a NotEmpty check to the Builder#withFactoryClassName(...) method might be sensible.
• adding a NotEmpty check to the constructor might be sensible (an empty string here makes no sense)