/**
 * Parses a list of elements into a set of beans/standard content.
 *
 * @param grandChildren - The set of beans/content in a bean property
 * @param child - The property tag for the parent.
 * @param parent - The parent bean that the tag is nested in.
 * @param parserContext - Provided information and functionality regarding current bean set.
 * @return A managedSet of the nested content.
 */
protected ManagedSet parseSet(ArrayList<Element> grandChildren, Element child, BeanDefinitionBuilder parent,
        ParserContext parserContext) {
    ManagedSet setItems = new ManagedSet();

    for (int i = 0; i < grandChildren.size(); i++) {
        Element grandChild = grandChildren.get(i);

        if (child.getTagName().compareTo("value") == 0) {
            setItems.add(grandChild.getTextContent());
        } else {
            setItems.add(parseBean(grandChild, parent, parserContext));
        }
    }

    String merge = child.getAttribute("merge");
    if (merge != null) {
        setItems.setMergeEnabled(Boolean.valueOf(merge));
    }

    return setItems;
}
 

/**
 * Iterates through the set values and calls helpers to process the value
 *
 * @param setVal the set to process
 * @param propertyName name of the property which has the set value
 * @param nestedBeanStack stack of bean containers which contains the set property
 */
protected void visitSet(Set setVal, String propertyName, Stack<BeanDefinitionHolder> nestedBeanStack) {
    boolean isMergeEnabled = false;
    if (setVal instanceof ManagedSet) {
        isMergeEnabled = ((ManagedSet) setVal).isMergeEnabled();
    }

    ManagedSet newSet = new ManagedSet();
    newSet.setMergeEnabled(isMergeEnabled);

    for (Object elem : setVal) {
        if (isStringValue(elem)) {
            elem = processSetStringPropertyValue(propertyName, setVal, getString(elem), nestedBeanStack,
                    beanProcessors);
        } else {
            elem = visitPropertyValue(propertyName, elem, nestedBeanStack);
        }

        newSet.add(elem);
    }

    setVal.clear();
    setVal.addAll(newSet);
}
 

private XStream createStream() {
	XStream stream = new XStream();
	stream.registerConverter(new BeanDefinitionConverter(stream.getMapper()));
	stream.registerConverter(new BeanDefinitionHolderConverter(stream.getMapper()));
	stream.registerConverter(new TypedStringValueConverter());
	stream.registerConverter(new ManagedCollectionConverter(stream.getMapper()));
	stream.registerConverter(new ManagedMapConverter(stream.getMapper()));
	stream.registerConverter(new RuntimeBeanReferenceConverter());
	stream.alias("map", ManagedMap.class);
	stream.alias("list", ManagedList.class);
	stream.alias("set", ManagedSet.class);
	stream.alias("array", ManagedArray.class);
	stream.aliasType("bean", BeanDefinition.class);
	stream.alias("bean", BeanDefinitionHolder.class);
	stream.alias("ref", RuntimeBeanReference.class);
	return stream;
}
 

/**
 * Parse a set element.
 */
public Set<Object> parseSetElement(Element collectionEle, @Nullable BeanDefinition bd) {
	String defaultElementType = collectionEle.getAttribute(VALUE_TYPE_ATTRIBUTE);
	NodeList nl = collectionEle.getChildNodes();
	ManagedSet<Object> target = new ManagedSet<>(nl.getLength());
	target.setSource(extractSource(collectionEle));
	target.setElementTypeName(defaultElementType);
	target.setMergeEnabled(parseMergeAttribute(collectionEle));
	parseCollectionElements(nl, target, bd, defaultElementType);
	return target;
}
 

/**
 * Parse a set element.
 */
public Set<Object> parseSetElement(Element collectionEle, @Nullable BeanDefinition bd) {
	String defaultElementType = collectionEle.getAttribute(VALUE_TYPE_ATTRIBUTE);
	NodeList nl = collectionEle.getChildNodes();
	ManagedSet<Object> target = new ManagedSet<>(nl.getLength());
	target.setSource(extractSource(collectionEle));
	target.setElementTypeName(defaultElementType);
	target.setMergeEnabled(parseMergeAttribute(collectionEle));
	parseCollectionElements(nl, target, bd, defaultElementType);
	return target;
}
 

/** 获取瞬时策略集合 */
private static ManagedSet<Object> getTransienceStrategies(Element configurationElement, ParserContext context) {
    // 设置每个执行策略配置
    ManagedSet<Object> strategies = new ManagedSet<>();
    List<Element> elements = XmlUtility.getChildElementsByTagName(configurationElement, ElementDefinition.TRANSIENCE_STRATEGY.getName());
    for (Element element : elements) {
        String reference = element.getAttribute(AttributeDefinition.REFERENCE.getName());
        strategies.add(new RuntimeBeanReference(reference));
    }
    return strategies;
}
 

/** 获取持久策略集合 */
private static ManagedSet<Object> getPersistenceStrategies(Element configurationElement, ParserContext context) {
    // 设置每个执行策略配置
    ManagedSet<Object> strategies = new ManagedSet<>();
    List<Element> elements = XmlUtility.getChildElementsByTagName(configurationElement, ElementDefinition.PERSISTENCE_STRATEGY.getName());
    for (Element element : elements) {
        String reference = element.getAttribute(AttributeDefinition.REFERENCE.getName());
        strategies.add(new RuntimeBeanReference(reference));
    }
    return strategies;
}
 

/**
 * Parse a set element.
 */
public Set<Object> parseSetElement(Element collectionEle, BeanDefinition bd) {
	String defaultElementType = collectionEle.getAttribute(VALUE_TYPE_ATTRIBUTE);
	NodeList nl = collectionEle.getChildNodes();
	ManagedSet<Object> target = new ManagedSet<Object>(nl.getLength());
	target.setSource(extractSource(collectionEle));
	target.setElementTypeName(defaultElementType);
	target.setMergeEnabled(parseMergeAttribute(collectionEle));
	parseCollectionElements(nl, target, bd, defaultElementType);
	return target;
}
 

/**
 * Parse a set element.
 */
public Set<Object> parseSetElement(Element collectionEle, BeanDefinition bd) {
	String defaultElementType = collectionEle.getAttribute(VALUE_TYPE_ATTRIBUTE);
	NodeList nl = collectionEle.getChildNodes();
	ManagedSet<Object> target = new ManagedSet<Object>(nl.getLength());
	target.setSource(extractSource(collectionEle));
	target.setElementTypeName(defaultElementType);
	target.setMergeEnabled(parseMergeAttribute(collectionEle));
	parseCollectionElements(nl, target, bd, defaultElementType);
	return target;
}
 

/**
 * Parse a set element.
 */
public Set<Object> parseSetElement(Element collectionEle, BeanDefinition bd) {
	String defaultElementType = collectionEle.getAttribute(VALUE_TYPE_ATTRIBUTE);
	NodeList nl = collectionEle.getChildNodes();
	ManagedSet<Object> target = new ManagedSet<Object>(nl.getLength());
	target.setSource(extractSource(collectionEle));
	target.setElementTypeName(defaultElementType);
	target.setMergeEnabled(parseMergeAttribute(collectionEle));
	parseCollectionElements(nl, target, bd, defaultElementType);
	return target;
}
 

public boolean canConvert(Class type) {
	return type.equals(ManagedList.class) || type.equals(ManagedArray.class) || type.equals(ManagedSet.class);
}