global.namespace.neuron.di.internal.RealIncubator Maven / Gradle / Ivy

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/*
 * Copyright © 2016 Schlichtherle IT Services
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package global.namespace.neuron.di.internal;

import global.namespace.neuron.di.java.BreedingException;

import java.lang.reflect.InvocationTargetException;
import java.util.Collections;
import java.util.Map;
import java.util.WeakHashMap;

public final class RealIncubator {

    private static final Map, ProxyFactory> factories = Collections.synchronizedMap(new WeakHashMap<>());

    private RealIncubator() {
    }

    public static  C breed(Class clazz, MethodBinding binding) {
        return new Visitor() {

            C instance;

            {
                ClassElement.of(clazz).accept(this);
            }

            @SuppressWarnings("unchecked")
            @Override
            public void visitNeuron(NeuronElement element) {
                assert clazz == element.clazz();
                final ProxyFactory factory = (ProxyFactory) factories
                        .computeIfAbsent(clazz, key -> new ProxyContext<>(element).factory());
                instance = factory.apply(binding);
            }

            @Override
            public void visitClass(final ClassElement element) {
                assert clazz == element.clazz();
                try {
                    instance = clazz.getDeclaredConstructor().newInstance();
                } catch (NoSuchMethodException e) {
                    throw new BreedingException("Class must have a non-private constructor without parameters.", e);
                } catch (InstantiationException e) {
                    throw new AssertionError(e);
                } catch (IllegalAccessException | InvocationTargetException e) {
                    throw new BreedingException(e);
                }
            }
        }.instance;
    }
}