com.github.nill14.utils.init.impl.QualifiedProvider Maven / Gradle / Ivy

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package com.github.nill14.utils.init.impl;

import java.lang.annotation.Annotation;
import java.util.Optional;

import javax.inject.Provider;

import com.github.nill14.utils.init.api.BindingKey;
import com.github.nill14.utils.init.api.IParameterType;
import com.github.nill14.utils.init.api.IPropertyResolver;
import com.github.nill14.utils.init.api.IQualifiedProvider;
import com.google.common.reflect.TypeToken;

@SuppressWarnings("unchecked")
public class QualifiedProvider implements IQualifiedProvider {
	
	private final IPropertyResolver resolver;
	private final TypeToken typeToken;

	public QualifiedProvider(TypeToken typeToken, IPropertyResolver resolver) {
		this.typeToken = typeToken;
		this.resolver = resolver;
	}
	

	private T resolveOrThrow(IParameterType type) {
		T object = (T) resolver.resolve(type);
		if (object != null) {
			return object;
		} else {
			throw new RuntimeException("Cannot resolve " + type.getQualifier());
		}
	}
	
	private Optional resolveOptional(IParameterType type) {
		return Optional.ofNullable((T) resolver.resolve(type));
	}

	@Override
	public T getNamed(String named) {
		IParameterType type = IParameterType.of(BindingKey.of(typeToken, named));
		return resolveOrThrow(type);
	}

	@Override
	public Optional getOptionalNamed(String named) {
		IParameterType type = IParameterType.of(BindingKey.of(typeToken, named));
		return resolveOptional(type);
	}

	@Override
	public T getQualified(Class annotationType) {
		IParameterType type = IParameterType.of(BindingKey.of(typeToken, annotationType));
		return resolveOrThrow(type);
	}

	@Override
	public Optional getOptionalQualified(Class annotationType) {
		IParameterType type = IParameterType.of(BindingKey.of(typeToken, annotationType));
		return resolveOptional(type);
	}

	@Override
	public T getQualified(Annotation annotation) {
		IParameterType type = IParameterType.of(BindingKey.of(typeToken, annotation));
		return resolveOrThrow(type);
	}

	@Override
	public Optional getOptionalQualified(Annotation annotation) {
		IParameterType type = IParameterType.of(BindingKey.of(typeToken, annotation));
		return resolveOptional(type);
	}
	
	private final Provider> provider = new Provider>() {
		
		@Override
		public QualifiedProvider get() {
			return QualifiedProvider.this;
		}
	};
	
	public Provider> toProvider() {
		return provider;
	}
}