ConfigurationValueProducer.java

/**
 * Copyright 2015-2016 Red Hat, Inc, and individual contributors.
 *
 * 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
 *
 * http://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 org.wildfly.swarm.container.runtime.cdi;

import java.lang.annotation.Annotation;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.Optional;

import javax.enterprise.context.ApplicationScoped;
import javax.enterprise.context.Dependent;
import javax.enterprise.inject.Produces;
import javax.enterprise.inject.spi.InjectionPoint;
import javax.inject.Inject;

import org.wildfly.swarm.spi.api.config.ConfigView;
import org.wildfly.swarm.spi.api.config.Resolver;
import org.wildfly.swarm.spi.runtime.annotations.ConfigurationValue;

/**
 * @author Martin Kouba
 */
@ApplicationScoped
public class ConfigurationValueProducer {

    @Inject
    private ConfigView configView;

    @Produces
    @ConfigurationValue("")
    @Dependent
    Resolver<String> produceResolver(InjectionPoint injectionPoint) {
        return resolver(injectionPoint);
    }

    @Produces
    @ConfigurationValue("")
    @Dependent
    String produceStringConfigValue(InjectionPoint injectionPoint) {
        return resolve(injectionPoint, String.class);
    }


    @Produces
    @ConfigurationValue("")
    @Dependent
    Integer produceIntegerConfigValue(InjectionPoint injectionPoint) {
        return resolve(injectionPoint, Integer.class);
    }

    @Produces
    @Dependent
    @ConfigurationValue("")
    Boolean produceBooleanConfigValue(InjectionPoint injectionPoint) {
        return resolve(injectionPoint, Boolean.class);
    }

    @ConfigurationValue("")
    @Dependent
    @Produces
    Long produceLongConfigValue(InjectionPoint injectionPoint) {
        return resolve(injectionPoint, Long.class);
    }

    @ConfigurationValue("")
    @Dependent
    @Produces
    Float produceFloatConfigValue(InjectionPoint injectionPoint) {
        return resolve(injectionPoint, Float.class);
    }

    @ConfigurationValue("")
    @Dependent
    @Produces
    Double produceDoubleConfigValue(InjectionPoint injectionPoint) {
        return resolve(injectionPoint, Double.class);
    }

    @SuppressWarnings("unchecked")
    @ConfigurationValue("")
    @Dependent
    @Produces
    <T> Optional<T> produceOptionalConfigValue(InjectionPoint injectionPoint) {
        Type type = injectionPoint.getAnnotated().getBaseType();
        final Class<T> valueType;
        if (type instanceof ParameterizedType) {
            ParameterizedType parameterizedType = (ParameterizedType) type;

            Type[] typeArguments = parameterizedType.getActualTypeArguments();
            valueType = unwrapType(typeArguments[0]);
        } else {
            valueType = (Class<T>) String.class;
        }
        return Optional.ofNullable(resolve(injectionPoint, valueType));
    }

    @SuppressWarnings("unchecked")
    private <T> Class<T> unwrapType(Type type) {
        if (type instanceof ParameterizedType) {
            type = ((ParameterizedType) type).getRawType();
        }
        return (Class<T>) type;
    }


    private <T> T resolve(InjectionPoint injectionPoint, Class<T> target) {
        Resolver<String> resolver = resolver(injectionPoint);
        try {
            return resolver != null ? resolver.as(target).getValue() : null;
        } catch (RuntimeException e) {
            return null;
        }
    }

    private Resolver<String> resolver(InjectionPoint injectionPoint) {
        String name = getName(injectionPoint);
        if (name == null || name.isEmpty() || this.configView == null) {
            return null;
        }
        return this.configView.resolve(name);
    }

    private String getName(InjectionPoint injectionPoint) {
        for (Annotation qualifier : injectionPoint.getQualifiers()) {
            if (qualifier.annotationType().equals(ConfigurationValue.class)) {
                return ((ConfigurationValue) qualifier).value();
            }
        }
        return null;
    }

}