I have a factory(Registry DP) which initializes the class:
public class GenericFactory extends AbstractFactory {
public GenericPostProcessorFactory() {
factory.put("Test",
defaultSupplier(() -> new Test()));
factory.put("TestWithArgs",
defaultSupplier(() -> new TestWithArgs(2,4)));
}
}
interface Validation
Test implements Validation
TestWithArgs implements Validation
And in the AbstractFactory
protected Supplier<Validation> defaultSupplier(Class<? extends Validation> validationClass) {
return () -> {
try {
return validationClass.newInstance();
} catch (InstantiationException | IllegalAccessException e) {
throw new RuntimeException("Unable to create instance of " + validationClass, e);
}
};
}
But I keep getting Cannot infer functional interface type Error. What I am doing wrong here ?
1 Answer
Your defaultSupplier method has an argument type of Class. You can’t pass a lambda expression where a Class is expected. But you don’t need that method defaultSupplier anyway.
Since Test and TestWithArgs are a subtypes of Validation, the lambda expressions () -> new Test() and () -> new TestWithArgs(2,4) are already assignable to Supplier<Validation> without that method:
public class GenericFactory extends AbstractFactory {
public GenericPostProcessorFactory() {
factory.put("Test", () -> new Test());
factory.put("TestWithArgs", () -> new TestWithArgs(2,4));
}
}
