树形结构转换xml总结

树形结构转换xml总结

      这几天碰见个问题，需要将库里的树形结构存储数据转换为xml形式，从而可以利用XMind进行查看。类似这种结构：

0 -1 父节点
101 0 节点1
102 0 节点2
2101001 101 节点4

一、基本思路

      从库里导出数据存入文件中，也可以直接从库中读取数据。

二、实现步骤

1、定义节点类型：

import java.util.List;

public class Node {

	private String id;        //节点id
	private String parentId;  //父节点id
	private String Text;  //节点名称
	private List<Node> children;  //子节点
	
	
	public Node(String id, String parentId, String Text) {
		super();
		this.id = id;
		this.parentId = parentId;
		this.Text = Text;
	}
	
		
	public Node(String id, String Text, Node parent) {
		super();
		this.id = id;
		this.Text = Text;
		this.parentId = parent.getId();
	}
	
	public String getId() {
		return id;
	}
	public void setId(String id) {
		this.id = id;
	}
	public String getParentId() {
		return parentId;
	}
	public void setParentId(String parentId) {
		this.parentId = parentId;
	}
	public String getText() {
		return Text;
	}
	public void setText(String Text) {
		this.Text = Text;
	}
	public List<Node> getChildren() {
		return children;
	}
	public void setChildren(List<Node> children) {
		this.children = children;
	}
}

2、将list类型装换成树形结构

findById、和 findByPid 分别为通过id 查找节点， 和通过节点查找子节点。

public List<Node> getTree() {
	List<Node> root = findById("0");       //get root node  
	return buildTreeMulti(root);
}
	
private List<Node> buildTreeMulti(List<Node> root) {
	for(int i=0; i < root.size(); i++) {
		List<Node> children = findByPid(root.get(i).getId());
		buildTreeMulti(children);
		root.get(i).setChildren(children);
	}
	return root;
}

3、将树形结构写入XML

 private static void writetoXML(List<Node> treeroot, String outfile) throws Exception {
		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
		DocumentBuilder builder = factory.newDocumentBuilder();
		Document doc = builder.newDocument();
		doc.setXmlStandalone(true);
		Element root = doc.createElement("map");
		root.setAttribute("version", "0.8.1");
		doc.appendChild(root);		
		doc = buildXML(treeroot, doc, root);
		writeXml(doc, outfile);
}

private static Document buildXML(List<Node> nodes, Document doc, Element faEle) {
	for(int i=0; i < nodes.size(); i++) {
		Element fa = doc.createElement("node");
		fa.setAttribute("TEXT", nodes.get(i).getText());
		faEle.appendChild(fa);
		List<Node> childtrees = nodes.get(i).getChildren();
		doc = buildXML(childtrees, doc, fa);
	}
	return doc;
}

public static void writeXml(Document document, String outfile) throws Exception{
	TransformerFactory tFactory = TransformerFactory.newInstance();
	Transformer transformer = tFactory.newTransformer();
	transformer.setOutputProperty("encoding", "UTF-8");
	DOMSource source = new DOMSource(document);
	StreamResult result = new StreamResult(outfile);
	transformer.transform(source, result);	
}

三、扩展

    相应的也可以把xml中的数据装换到Excel中等。

参考博文：https://blog.csdn.net/u012116457/article/details/45912887（网页形式展示树形结构）