content: /**
   *  Licensed to the Apache Software Foundation (ASF) under one or more
   *  contributor license agreements.  See the NOTICE file distributed with
   *  this work for additional information regarding copyright ownership.
   *  The ASF licenses this file to You 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.apache.aries.blueprint.spring;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.net.URL;
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.Hashtable;
  import java.util.List;
  import java.util.Map;
  import java.util.Properties;
  
  import org.apache.aries.blueprint.NamespaceHandler;
  import org.apache.felix.utils.extender.Extension;
  import org.osgi.framework.Bundle;
  import org.osgi.framework.FrameworkUtil;
  import org.osgi.framework.ServiceRegistration;
  import org.springframework.beans.factory.BeanFactory;
  import org.springframework.beans.factory.xml.BeanDefinitionParserDelegate;
  
  /**
   * Spring extension.
   * Each spring namespace is wrapped in a blueprint namespace.
   *
   * @see BlueprintNamespaceHandler
   */
  public class SpringExtension implements Extension {
  
      public static final String SPRING_HANDLERS = "META-INF/spring.handlers";
      public static final String SPRING_SCHEMAS = "META-INF/spring.schemas";
  
      private final Bundle bundle;
      private final List<ServiceRegistration<NamespaceHandler>> registrations;
  
      public SpringExtension(Bundle bundle) {
          this.bundle = bundle;
          this.registrations = new ArrayList<ServiceRegistration<NamespaceHandler>>();
      }
  
      @Override
      public void start() throws Exception {
          Map<String, NamespaceHandler> handlers = new HashMap<String, NamespaceHandler>();
          Properties props = loadSpringHandlers();
          Properties schemas = loadSpringSchemas();
          for (String key : props.stringPropertyNames()) {
              String clazzName = props.getProperty(key);
              org.springframework.beans.factory.xml.NamespaceHandler springHandler
                      = (org.springframework.beans.factory.xml.NamespaceHandler) bundle.loadClass(clazzName).newInstance();
              NamespaceHandler wrapper = new BlueprintNamespaceHandler(bundle, schemas, springHandler);
              handlers.put(key, wrapper);
          }
          if (bundle == FrameworkUtil.getBundle(BeanFactory.class)) {
              org.springframework.beans.factory.xml.NamespaceHandler springHandler
                      = new BeansNamespaceHandler();
              NamespaceHandler wrapper = new BlueprintNamespaceHandler(bundle, schemas, springHandler);
              handlers.put(BeanDefinitionParserDelegate.BEANS_NAMESPACE_URI, wrapper);
          }
          for (Map.Entry<String, NamespaceHandler> entry : handlers.entrySet()) {
              Hashtable<String, String> svcProps = new Hashtable<String, String>();
              svcProps.put("osgi.service.blueprint.namespace", entry.getKey());
              ServiceRegistration<NamespaceHandler> reg =
                      bundle.getBundleContext().registerService(NamespaceHandler.class, entry.getValue(),
                              svcProps);
              registrations.add(reg);
          }
      }
  
      private Properties loadSpringHandlers() throws IOException {
          Properties props = new Properties();
          URL url = bundle.getResource(SPRING_HANDLERS);
          InputStream is = url.openStream();
          try {
              props.load(is);
          } finally {
              is.close();
          }
          return props;
      }
  
      private Properties loadSpringSchemas() throws IOException {
          Properties props = new Properties();
          URL url = bundle.getResource(SPRING_SCHEMAS);
          InputStream is = url.openStream();
          try {
              props.load(is);
          } finally {
              is.close();
          }
          return props;
      }
  
      @Override
      public void destroy() throws Exception {
          for (ServiceRegistration<NamespaceHandler> reg : registrations) {
              reg.unregister();
          }
      }
  
  }
  