spring bean parse

BeanDefinitionParserDelegate.parseBeanDefinitionElement

/**
 * Parses the supplied {@code <bean>} element. May return {@code null}
 * if there were errors during parse. Errors are reported to the
 * {@link org.springframework.beans.factory.parsing.ProblemReporter}.
 */
@Nullable
public BeanDefinitionHolder parseBeanDefinitionElement(Element ele, @Nullable BeanDefinition containingBean) {
String id = ele.getAttribute(ID_ATTRIBUTE);
String nameAttr = ele.getAttribute(NAME_ATTRIBUTE);
List<String> aliases = new ArrayList<>();
if (StringUtils.hasLength(nameAttr)) {
   String[] nameArr = StringUtils.tokenizeToStringArray(nameAttr, MULTI_VALUE_ATTRIBUTE_DELIMITERS);
   aliases.addAll(Arrays.asList(nameArr));
}
String beanName = id;
if (!StringUtils.hasText(beanName) && !aliases.isEmpty()) {
   beanName = aliases.remove(0);
   if (logger.isDebugEnabled()) {
      logger.debug("No XML 'id' specified - using '" + beanName +
            "' as bean name and " + aliases + " as aliases");
   }
}
if (containingBean == null) {
   checkNameUniqueness(beanName, aliases, ele);
}
AbstractBeanDefinition beanDefinition = parseBeanDefinitionElement(ele, beanName, containingBean);
if (beanDefinition != null) {
   if (!StringUtils.hasText(beanName)) {
      try {
         if (containingBean != null) {
            beanName = BeanDefinitionReaderUtils.generateBeanName(
                  beanDefinition, this.readerContext.getRegistry(), true);
         }
         else {
            beanName = this.readerContext.generateBeanName(beanDefinition);
            // Register an alias for the plain bean class name, if still possible,
            // if the generator returned the class name plus a suffix.
            // This is expected for Spring 1.2/2.0 backwards compatibility.
            String beanClassName = beanDefinition.getBeanClassName();
            if (beanClassName != null &&
                  beanName.startsWith(beanClassName) && beanName.length() > beanClassName.length() &&
                  !this.readerContext.getRegistry().isBeanNameInUse(beanClassName)) {
               aliases.add(beanClassName);
            }
         }
         if (logger.isDebugEnabled()) {
            logger.debug("Neither XML 'id' nor 'name' specified - " +
                  "using generated bean name [" + beanName + "]");
         }
      }
      catch (Exception ex) {
         error(ex.getMessage(), ele);
         return null;
      }
   }
   String[] aliasesArray = StringUtils.toStringArray(aliases);
   return new BeanDefinitionHolder(beanDefinition, beanName, aliasesArray);
}
return null;
}