GlobalBeanDefinitionUtils.java

/*
 * Copyright 2013-2014 the original author or authors.
 *
 * 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.springframework.cloud.aws.context.config.xml;

import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.support.BeanDefinitionBuilder;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.cloud.aws.core.env.ResourceIdResolver;
import org.springframework.cloud.aws.core.env.StackResourceRegistryDetectingResourceIdResolver;

/**
 * Provides utility methods for registering globally used bean definitions.
 *
 * @author Christian Stettler
 * @author Alain Sahli
 * @author Agim Emruli
 */
public final class GlobalBeanDefinitionUtils {

    public static final String RESOURCE_ID_RESOLVER_BEAN_NAME = ResourceIdResolver.class.getName() + ".BEAN_NAME";

    private GlobalBeanDefinitionUtils() {
        // Avoid instantiation
    }

    /**
     * Returns the name of the resource id resolver bean. This method is provided as utility method for bean definition
     * parsers that create bean definitions with a dependency to the global resource id resolver bean. If the resource
     * id resolver bean of type {@link ResourceIdResolver} has not yet been registered with the provided bean definition
     * registry, it is automatically registered.
     *
     * @param registry
     *         the bean definition registry to check for an existing resource id resolver bean definition, and to register the
     *         resource id resolver bean definition with, if needed
     * @return the bean name of the resource id resolver bean
     */
    @SuppressWarnings("SameReturnValue")
    public static String retrieveResourceIdResolverBeanName(BeanDefinitionRegistry registry) {
        registerResourceIdResolverBeanIfNeeded(registry);

        return RESOURCE_ID_RESOLVER_BEAN_NAME;
    }

    static void registerResourceIdResolverBeanIfNeeded(BeanDefinitionRegistry registry) {
        if (!(registry.containsBeanDefinition(RESOURCE_ID_RESOLVER_BEAN_NAME))) {
            registry.registerBeanDefinition(RESOURCE_ID_RESOLVER_BEAN_NAME, buildResourceIdResolverBeanDefinition());
        }
    }

    private static BeanDefinition buildResourceIdResolverBeanDefinition() {
        return BeanDefinitionBuilder.genericBeanDefinition(StackResourceRegistryDetectingResourceIdResolver.class).getBeanDefinition();
    }


}