AmazonRdsDataSourceBeanDefinitionParser.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.jdbc.config.xml;

import org.springframework.beans.factory.BeanDefinitionStoreException;
import org.springframework.beans.factory.config.MethodInvokingFactoryBean;
import org.springframework.beans.factory.config.RuntimeBeanReference;
import org.springframework.beans.factory.support.AbstractBeanDefinition;
import org.springframework.beans.factory.support.BeanDefinitionBuilder;
import org.springframework.beans.factory.xml.AbstractBeanDefinitionParser;
import org.springframework.beans.factory.xml.ParserContext;
import org.springframework.cloud.aws.context.config.xml.GlobalBeanDefinitionUtils;
import org.springframework.cloud.aws.core.config.AmazonWebserviceClientConfigurationUtils;
import org.springframework.cloud.aws.jdbc.datasource.TomcatJdbcDataSourceFactory;
import org.springframework.cloud.aws.jdbc.rds.AmazonRdsDataSourceFactoryBean;
import org.springframework.cloud.aws.jdbc.rds.AmazonRdsReadReplicaAwareDataSourceFactoryBean;
import org.springframework.core.Conventions;
import org.springframework.util.StringUtils;
import org.springframework.util.xml.DomUtils;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;

import static org.springframework.cloud.aws.core.config.xml.XmlWebserviceConfigurationUtils.getCustomClientOrDefaultClientBeanName;

/**
 * {@link org.springframework.beans.factory.xml.BeanDefinitionParser} parser implementation for the datasource
 * element. Parses the element and constructs a fully configured {@link AmazonRdsDataSourceFactoryBean} bean
 * definition. Also creates a bean definition for the {@link com.amazonaws.services.rds.AmazonRDSClient} if there is
 * not already an existing one this application context.
 *
 * @author Agim Emruli
 * @since 1.0
 */
class AmazonRdsDataSourceBeanDefinitionParser extends AbstractBeanDefinitionParser {

    static final String DB_INSTANCE_IDENTIFIER = "db-instance-identifier";
    private static final String AMAZON_RDS_CLIENT_CLASS_NAME = "com.amazonaws.services.rds.AmazonRDSClient";
    private static final String IDENTITY_MANAGEMENT_CLIENT_CLASS_NAME = "com.amazonaws.services.identitymanagement.AmazonIdentityManagementClient";
    private static final String USER_TAG_FACTORY_BEAN_CLASS_NAME = "org.springframework.cloud.aws.jdbc.rds.AmazonRdsDataSourceUserTagsFactoryBean";
    private static final String USERNAME = "username";
    private static final String PASSWORD = "password";
    private static final String DATABASE_NAME = "database-name";

    @Override
    protected AbstractBeanDefinition parseInternal(Element element, ParserContext parserContext) {
        BeanDefinitionBuilder datasourceBuilder = getBeanDefinitionBuilderForDataSource(element);

        //Constructor (mandatory) args
        String amazonRdsClientBeanName = getCustomClientOrDefaultClientBeanName(element, parserContext, "amazon-rds", AMAZON_RDS_CLIENT_CLASS_NAME);
        datasourceBuilder.addConstructorArgReference(amazonRdsClientBeanName);
        datasourceBuilder.addConstructorArgValue(element.getAttribute(DB_INSTANCE_IDENTIFIER));
        datasourceBuilder.addConstructorArgValue(element.getAttribute(PASSWORD));

        //optional args
        if (StringUtils.hasText(element.getAttribute(USERNAME))) {
            datasourceBuilder.addPropertyValue(USERNAME, element.getAttribute(USERNAME));
        }

        if (StringUtils.hasText(element.getAttribute(DATABASE_NAME))) {
            datasourceBuilder.addPropertyValue(Conventions.attributeNameToPropertyName(DATABASE_NAME), element.getAttribute(DATABASE_NAME));
        }

        datasourceBuilder.addPropertyValue("dataSourceFactory", createDataSourceFactoryBeanDefinition(element));

        //Register registry to enable cloud formation support
        String resourceResolverBeanName = GlobalBeanDefinitionUtils.retrieveResourceIdResolverBeanName(parserContext.getRegistry());
        datasourceBuilder.addPropertyReference("resourceIdResolver", resourceResolverBeanName);

        registerUserTagsMapIfNecessary(element, parserContext, amazonRdsClientBeanName);

        return datasourceBuilder.getBeanDefinition();
    }

    private BeanDefinitionBuilder getBeanDefinitionBuilderForDataSource(Element element) {
        BeanDefinitionBuilder datasourceBuilder;
        if (Boolean.TRUE.toString().equalsIgnoreCase(element.getAttribute("read-replica-support"))) {
            datasourceBuilder = BeanDefinitionBuilder.rootBeanDefinition(AmazonRdsReadReplicaAwareDataSourceFactoryBean.class);
        } else {
            datasourceBuilder = BeanDefinitionBuilder.rootBeanDefinition(AmazonRdsDataSourceFactoryBean.class);
        }
        return datasourceBuilder;
    }

    /**
     * Creates a {@link org.springframework.cloud.aws.jdbc.datasource.DataSourceFactory} implementation. Uses the
     * TomcatJdbcDataSourceFactory implementation and passes all pool attributes from the xml directly to the class
     * (through setting the bean properties).
     *
     * @param element
     *         - The datasource element which may contain a pool-attributes element
     * @return - fully configured bean definition for the DataSourceFactory
     */
    private static AbstractBeanDefinition createDataSourceFactoryBeanDefinition(Element element) {
        BeanDefinitionBuilder datasourceFactoryBuilder = BeanDefinitionBuilder.rootBeanDefinition(TomcatJdbcDataSourceFactory.class);
        Element poolAttributes = DomUtils.getChildElementByTagName(element, "pool-attributes");
        if (poolAttributes != null) {
            NamedNodeMap attributes = poolAttributes.getAttributes();
            for (int i = 0, x = attributes.getLength(); i < x; i++) {
                Node item = attributes.item(i);
                datasourceFactoryBuilder.addPropertyValue(item.getNodeName(), item.getNodeValue());
            }
        }

        return datasourceFactoryBuilder.getBeanDefinition();
    }

    private static void registerUserTagsMapIfNecessary(Element element, ParserContext parserContext, String rdsClientBeanName) {
        if (!StringUtils.hasText(element.getAttribute("user-tags-map"))) {
            return;
        }

        BeanDefinitionBuilder builder = BeanDefinitionBuilder.genericBeanDefinition(USER_TAG_FACTORY_BEAN_CLASS_NAME);
        builder.addConstructorArgReference(rdsClientBeanName);
        builder.addConstructorArgValue(element.getAttribute(DB_INSTANCE_IDENTIFIER));
        builder.addConstructorArgReference(getCustomClientOrDefaultClientBeanName(element, parserContext, "amazon-identity-management",
                IDENTITY_MANAGEMENT_CLIENT_CLASS_NAME));

        // Use custom region-provider of data source
        if (StringUtils.hasText(element.getAttribute("region"))) {
            BeanDefinitionBuilder beanDefinitionBuilder = BeanDefinitionBuilder.genericBeanDefinition("com.amazonaws.regions.Region");
            beanDefinitionBuilder.setFactoryMethod("getRegion");
            beanDefinitionBuilder.addConstructorArgValue(element.getAttribute("region"));
            builder.addPropertyValue("region", beanDefinitionBuilder.getBeanDefinition());
        } else {
            BeanDefinitionBuilder beanDefinitionBuilder = BeanDefinitionBuilder.genericBeanDefinition(MethodInvokingFactoryBean.class);
            if (StringUtils.hasText(element.getAttribute("region-provider"))) {
                beanDefinitionBuilder.addPropertyValue("targetObject", new RuntimeBeanReference(element.getAttribute("region-provider")));
            } else {
                beanDefinitionBuilder.addPropertyValue("targetObject", new RuntimeBeanReference(AmazonWebserviceClientConfigurationUtils.
                        getRegionProviderBeanName(parserContext.getRegistry())));
            }
            beanDefinitionBuilder.addPropertyValue("targetMethod", "getRegion");
            builder.addPropertyValue("region", beanDefinitionBuilder.getBeanDefinition());
        }

        String resourceResolverBeanName = GlobalBeanDefinitionUtils.retrieveResourceIdResolverBeanName(parserContext.getRegistry());
        builder.addPropertyReference("resourceIdResolver", resourceResolverBeanName);

        parserContext.getRegistry().registerBeanDefinition(element.getAttribute("user-tags-map"), builder.getBeanDefinition());
    }

    @Override
    protected String resolveId(Element element, AbstractBeanDefinition definition, ParserContext parserContext) throws BeanDefinitionStoreException {
        return element.getAttribute(DB_INSTANCE_IDENTIFIER);
    }
}