package framework.util;

import java.io.File;
import java.io.StringReader;
import java.util.LinkedList;
import java.util.List;

import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;

/**
 * 转换 xml 与字符串
 *
 * @author liuyajun
 * @time 2014-12-27下午12:56:56
 *
 */
public class XmlUtil {
	
	/**
	 * 获取xml文件的根结点
	 * @param absXmlPath
	 * @return
	 * @throws Exception
	 */
	public static Element getXmlFileRoot(String absXmlPath) throws Exception{
		File file = new File(absXmlPath);

		DocumentBuilderFactory factory = DocumentBuilderFactory
				.newInstance();
		factory.setValidating(false);
		Document doc = factory.newDocumentBuilder().parse(file);

		return doc.getDocumentElement();
	}

	/**
	 * 获取 xml 字符串的根结点
	 * @param xml
	 * @return
	 */
	public static Node getXmlRoot(String xml){
		xml = xml.trim();
		if(! xml.startsWith("<?xml version=")){
			xml = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>" + xml;
		}
		
		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
		factory.setValidating(false);
        InputSource source = null;  
        StringReader reader = null;  
 
		try {
			reader = new StringReader(xml);  
            source = new InputSource(reader);
            
			Document doc = factory.newDocumentBuilder().parse(source);
			return doc.getDocumentElement();
		} catch (Exception e) {
			e.printStackTrace();
		}finally{
			if (reader != null) {
				reader.close();
			}
		}

		return null;
	}

	
	/**
	 * 得到节点属性值
	 * 
	 * @param node
	 * @param name
	 * @return
	 */
	public static String getAttributeValue(Node node, String name){
		if(node==null || name==null || name.trim().length()==0){
			return "";
		}
		name = name.trim();
		Node attr = node.getAttributes().getNamedItem(name);
		if(attr==null){
			return "";
		}
		return attr.getNodeValue().trim();
	}
	/**
	 * 得到相对于 node 的xmlPath节点的第一个节点文本内容
	 * @param node
	 * @param xmlPath
	 * @return
	 */
	public static final String getNodeTextContent(Node node, String xmlPath){
		Node n = getNode(node, xmlPath);
		if(n!=null){
			return n.getTextContent().trim();
		}
		return "";
	}
	/**
	 * 得到相对于 node 的 xmlPath 节点的第一个节点
	 * @param node
	 * @param xmlPath
	 * @return
	 */
	public static final Node getNode(Node node, String xmlPath){
		Node[] nodes = getNodeArray(node, xmlPath);
		if(nodes!=null && nodes.length>=1){
			return nodes[0];
		}
		return null;
	}
	/**
	 * 根据XML结点路径, 返回节点数组
	 * @param node	结点
	 * @param xmlPath	相对于结点的XML路径
	 * @return
	 */
	public static final Node[] getNodeArray(Node node, String xmlPath){
		if(node==null){
			return null;
		}
		if(xmlPath==null){
			return new Node[]{node};
		}
		//规范路径
		xmlPath = xmlPath.trim();
		if(xmlPath.startsWith("/")){
			xmlPath = xmlPath.substring(1);
		}
		if(xmlPath.endsWith("/")){
			xmlPath = xmlPath.substring(0, xmlPath.length()-1);
		}
		
		//分解路径
		String[] paths = xmlPath.split("/");
		
		//无路径直接返回本身
		if(paths.length==0){
			return new Node[]{node};
		}
		
		List<Node> list = new LinkedList<Node>();
		
		//路径长度为1, 输出下级节点
		if(paths.length==1){
			NodeList nodes = node.getChildNodes();
			
			for(int i=0, size=nodes.getLength(); i<size; i++){
				if(nodes.item(i).getNodeName().equals(paths[0].trim())){
					list.add(nodes.item(i));
				}
			}
			
			return (Node[])list.toArray(new Node[0]);
		}
		
		Node[] tmp = new Node[]{node};
		list.clear();
		
		for(String path : paths){
			for(Node n : tmp){
				NodeList nodes = n.getChildNodes();
				for(int i=0, size=nodes.getLength(); i<size; i++){
					if(nodes.item(i).getNodeName().equals(path.trim())){
						list.add(nodes.item(i));
					}
				}
			}
			
			tmp = (Node[])list.toArray(new Node[0]);
			list.clear();
		}
		
		return tmp;
	}

}