AmazonWebserviceClientConfigurationUtils.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.core.config;

import com.amazonaws.regions.Regions;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.config.BeanDefinitionHolder;
import org.springframework.beans.factory.support.AbstractBeanDefinition;
import org.springframework.beans.factory.support.BeanDefinitionBuilder;
import org.springframework.beans.factory.support.BeanDefinitionReaderUtils;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.cloud.aws.core.credentials.CredentialsProviderFactoryBean;
import org.springframework.cloud.aws.core.region.StaticRegionProvider;
import org.springframework.util.ClassUtils;
import org.springframework.util.StringUtils;

import java.beans.Introspector;

/**
 * @author Agim Emruli
 * @author Alain Sahli
 */
public final class AmazonWebserviceClientConfigurationUtils {

    private static final String SERVICE_IMPLEMENTATION_SUFFIX = "Client";
    public static final String REGION_PROVIDER_BEAN_NAME = "org.springframework.cloud.aws.core.region.RegionProvider.BEAN_NAME";
    public static final String CREDENTIALS_PROVIDER_BEAN_NAME = "org.springframework.cloud.aws.core.credentials.CredentialsProviderFactoryBean.BEAN_NAME";

    private AmazonWebserviceClientConfigurationUtils() {
        // Avoid instantiation
    }

    public static BeanDefinitionHolder registerAmazonWebserviceClient(
            Object source, BeanDefinitionRegistry registry, String serviceNameClassName,
            String customRegionProvider, String customRegion) {

        String beanName = getBeanName(serviceNameClassName);

        if (registry.containsBeanDefinition(beanName)) {
            return new BeanDefinitionHolder(registry.getBeanDefinition(beanName), beanName);
        }

        BeanDefinition definition = getAmazonWebserviceClientBeanDefinition(source, serviceNameClassName, customRegionProvider, customRegion, registry);
        BeanDefinitionHolder holder = new BeanDefinitionHolder(definition, beanName);
        BeanDefinitionReaderUtils.registerBeanDefinition(holder, registry);

        return holder;
    }

    public static AbstractBeanDefinition getAmazonWebserviceClientBeanDefinition(
            Object source, String serviceNameClassName,
            String customRegionProvider, String customRegion, BeanDefinitionRegistry beanDefinitionRegistry) {

        if (StringUtils.hasText(customRegionProvider) && StringUtils.hasText(customRegion)) {
            throw new IllegalArgumentException("Only region or regionProvider can be configured, but not both");
        }

        registerCredentialsProviderIfNeeded(beanDefinitionRegistry);

        BeanDefinitionBuilder builder = BeanDefinitionBuilder.rootBeanDefinition(AmazonWebserviceClientFactoryBean.class);

        //Configure constructor parameters
        builder.addConstructorArgValue(serviceNameClassName);
        builder.addConstructorArgReference(CREDENTIALS_PROVIDER_BEAN_NAME);

        //Configure source of the bean definition
        builder.getRawBeanDefinition().setSource(source);

        //Configure region properties (either custom region provider or custom region)
        if (StringUtils.hasText(customRegionProvider)) {
            builder.addPropertyReference("regionProvider", customRegionProvider);
        } else if (StringUtils.hasText(customRegion)) {
            builder.addPropertyValue("customRegion", customRegion);
        } else {
            registerRegionProviderBeanIfNeeded(beanDefinitionRegistry);
            builder.addPropertyReference("regionProvider", REGION_PROVIDER_BEAN_NAME);
        }

        return builder.getBeanDefinition();
    }

    public static String getBeanName(String serviceClassName) {
        String clientClassName = ClassUtils.getShortName(serviceClassName);
        String shortenedClassName = StringUtils.delete(clientClassName, SERVICE_IMPLEMENTATION_SUFFIX);
        return Introspector.decapitalize(shortenedClassName);
    }

    public static String getRegionProviderBeanName(BeanDefinitionRegistry beanDefinitionRegistry) {
        registerRegionProviderBeanIfNeeded(beanDefinitionRegistry);
        return REGION_PROVIDER_BEAN_NAME;
    }

    public static void replaceDefaultRegionProvider(BeanDefinitionRegistry registry, String customGlobalRegionProvider) {
        if (registry.containsBeanDefinition(REGION_PROVIDER_BEAN_NAME)) {
            registry.removeBeanDefinition(REGION_PROVIDER_BEAN_NAME);
        }
        registry.registerAlias(customGlobalRegionProvider, REGION_PROVIDER_BEAN_NAME);
    }

    private static void registerRegionProviderBeanIfNeeded(BeanDefinitionRegistry registry) {
        if (!registry.containsBeanDefinition(REGION_PROVIDER_BEAN_NAME)) {
            BeanDefinitionBuilder builder = BeanDefinitionBuilder.genericBeanDefinition(StaticRegionProvider.class);
            builder.addConstructorArgValue(Regions.DEFAULT_REGION.getName());
            builder.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
            registry.registerBeanDefinition(REGION_PROVIDER_BEAN_NAME, builder.getBeanDefinition());
        }
    }

    private static void registerCredentialsProviderIfNeeded(BeanDefinitionRegistry registry) {
        if (!registry.containsBeanDefinition(CREDENTIALS_PROVIDER_BEAN_NAME)) {
            BeanDefinitionBuilder builder = BeanDefinitionBuilder.genericBeanDefinition(CredentialsProviderFactoryBean.class);
            builder.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
            registry.registerBeanDefinition(CREDENTIALS_PROVIDER_BEAN_NAME, builder.getBeanDefinition());
        }
    }

    public static void replaceDefaultCredentialsProvider(BeanDefinitionRegistry registry, String customGlobalCredentialsProvider) {
        if (registry.containsBeanDefinition(CREDENTIALS_PROVIDER_BEAN_NAME)) {
            registry.removeBeanDefinition(CREDENTIALS_PROVIDER_BEAN_NAME);
        }
        registry.registerAlias(customGlobalCredentialsProvider, CREDENTIALS_PROVIDER_BEAN_NAME);
    }
}