content: /*
   * Copyright 1999-2018 Alibaba Group Holding Ltd.
   *
   * 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 com.alibaba.druid.support.spring.stat.config;
  
  import org.springframework.beans.factory.config.BeanDefinition;
  import org.springframework.beans.factory.config.BeanDefinitionHolder;
  import org.springframework.beans.factory.parsing.BeanComponentDefinition;
  import org.springframework.beans.factory.parsing.CompositeComponentDefinition;
  import org.springframework.beans.factory.support.BeanDefinitionBuilder;
  import org.springframework.beans.factory.support.BeanDefinitionRegistry;
  import org.springframework.beans.factory.xml.BeanDefinitionParser;
  import org.springframework.beans.factory.xml.ParserContext;
  import org.w3c.dom.Element;
  
  public class DruidStatBeanDefinitionParser implements BeanDefinitionParser {
      public static final String STAT_ANNOTATION_PROCESSOR_BEAN_NAME = "com.alibaba.druid.support.spring.stat.annotation.internalStatAnnotationBeanPostProcessor";
      public static final String STAT_ANNOTATION_PROCESSOR_BEAN_CLASS = "com.alibaba.druid.support.spring.stat.annotation.StatAnnotationBeanPostProcessor";
      public static final String STAT_ANNOTATION_ADVICE_BEAN_NAME = "druid-stat-interceptor";
      public static final String STAT_ANNOTATION_ADVICE_BEAN_CLASS = "com.alibaba.druid.support.spring.stat.DruidStatInterceptor";
  
      @Override
      public BeanDefinition parse(Element element, ParserContext parserContext) {
          Object source = parserContext.extractSource(element);
  
          CompositeComponentDefinition compDefinition = new CompositeComponentDefinition(element.getTagName(), source);
          parserContext.pushContainingComponent(compDefinition);
  
          BeanDefinitionRegistry registry = parserContext.getRegistry();
  
          if (registry.containsBeanDefinition(STAT_ANNOTATION_PROCESSOR_BEAN_NAME)) {
              parserContext.getReaderContext().error(
                      "Only one DruidStatBeanDefinitionParser may exist within the context.", source);
          } else {
              BeanDefinitionBuilder builder = BeanDefinitionBuilder
                      .genericBeanDefinition(STAT_ANNOTATION_PROCESSOR_BEAN_CLASS);
              builder.getRawBeanDefinition().setSource(source);
              registerComponent(parserContext, builder, STAT_ANNOTATION_PROCESSOR_BEAN_NAME);
          }
  
          if (!registry.containsBeanDefinition(STAT_ANNOTATION_ADVICE_BEAN_NAME)) {
              BeanDefinitionBuilder builder = BeanDefinitionBuilder
                      .genericBeanDefinition(STAT_ANNOTATION_ADVICE_BEAN_CLASS);
              builder.getRawBeanDefinition().setSource(source);
              registerComponent(parserContext, builder, STAT_ANNOTATION_ADVICE_BEAN_NAME);
          }
  
          parserContext.popAndRegisterContainingComponent();
  
          return null;
      }
  
      private static void registerComponent(ParserContext parserContext, BeanDefinitionBuilder builder,
                                            String beanName) {
          builder.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
          parserContext.getRegistry().registerBeanDefinition(beanName, builder.getBeanDefinition());
          BeanDefinitionHolder holder = new BeanDefinitionHolder(builder.getBeanDefinition(), beanName);
          parserContext.registerComponent(new BeanComponentDefinition(holder));
      }
  }
  