Java tutorial
/* * Copyright 2013 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.yarn.config.annotation; import java.util.Map; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.ImportSelector; import org.springframework.core.annotation.AnnotationAttributes; import org.springframework.core.type.AnnotationMetadata; import org.springframework.yarn.config.annotation.EnableYarn.Enable; import org.springframework.yarn.config.annotation.configuration.SpringYarnAppmasterConfiguration; import org.springframework.yarn.config.annotation.configuration.SpringYarnClientConfiguration; import org.springframework.yarn.config.annotation.configuration.SpringYarnConfiguration; import org.springframework.yarn.config.annotation.configuration.SpringYarnContainerConfiguration; /** * Spring {@link ImportSelector} choosing appropriate {@link Configuration} * based on {@link EnableYarn} annotation. * * @author Janne Valkealahti * */ public class SpringYarnConfigurationImportSelector implements ImportSelector { private final static Log log = LogFactory.getLog(SpringYarnConfigurationImportSelector.class); @Override public String[] selectImports(AnnotationMetadata importingClassMetadata) { Map<String, Object> attrMap = importingClassMetadata.getAnnotationAttributes(EnableYarn.class.getName()); AnnotationAttributes enableAttrs = AnnotationAttributes.fromMap(attrMap); Enable enable = enableAttrs.getEnum("enable"); String[] configs = new String[2]; if (enable == Enable.CLIENT) { configs[0] = SpringYarnClientConfiguration.class.getName(); } else if (enable == Enable.APPMASTER) { configs[0] = SpringYarnAppmasterConfiguration.class.getName(); } else if (enable == Enable.CONTAINER) { configs[0] = SpringYarnContainerConfiguration.class.getName(); } else { configs[0] = SpringYarnConfiguration.class.getName(); } configs[1] = ConfiguringBeanFactoryPostProcessorConfiguration.class.getName(); if (log.isDebugEnabled()) { log.debug("Using configs " + configs[0] + "," + configs[1]); } return configs; } }