java基础之(二) XML的写入和解析

超级简单操作xml 纯javaAPI 不借助第三方.
不善于表达,直接贴代码。

package io;

import java.io.File;
import java.io.FileOutputStream;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;

import util.DbUtils;

public class XML {
	public static final String SAVE_PATH = "d://student.xml";
	
	/**
	 * 添加节点
	 * @param doc 文档
	 * @param parent 父节点
	 * @param tagName 节点名称
	 * @param data 节点内容
	 * @return
	 */
	private static Element addElement(Document doc, Node parent,
			String tagName, String data) {
		Element element = doc.createElement(tagName);
		if (null != data) {
			Text text = doc.createTextNode(data);
			element.appendChild(text);
		}
		if (null != parent) {
			parent.appendChild(element);

		}
		return element;
	}
	/**
	 * 文档解析器
	 * @return
	 * @throws Exception
	 */
	private static DocumentBuilder getBuilder()throws Exception{
		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
		return factory.newDocumentBuilder();
	}
	/**
	 * 写XML
	 * @param savePath
	 * @throws Exception
	 */
	public static void writer(String savePath) throws Exception {
		// 创建document
		
		Document doc = getBuilder().newDocument();
		Element root = addElement(doc, doc, "students", null);

		// 写入document
		String sql = "select * from student";
		Connection conn = DbUtils.getConn();
		Statement state = conn.createStatement();
		ResultSet rs = state.executeQuery(sql);
		while (rs.next()) {
			Element student = addElement(doc, root, "student", null);
			addElement(doc, student, "id", rs.getString("id"));
			addElement(doc, student, "name", rs.getString("name"));
			addElement(doc, student, "age", rs.getString("age"));
			addElement(doc, student, "code", rs.getString("code"));
			addElement(doc, student, "sex", rs.getString("sex"));
			addElement(doc, student, "political", rs.getString("political"));
			addElement(doc, student, "origin", rs.getString("origin"));
			addElement(doc, student, "professional", rs
					.getString("professional"));
		}
		DbUtils.close(rs, state, conn);

		// 输出document
		TransformerFactory tf = TransformerFactory.newInstance();
		Transformer transformer = tf.newTransformer();
		//设定格式
		transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
		transformer.setOutputProperty(OutputKeys.INDENT, "yes");
		
		//转换器
		StreamResult result = new StreamResult(new FileOutputStream(savePath));
		DOMSource source = new DOMSource(doc);
		transformer.transform(source, result);

	}
	/**
	 * 读XML
	 * @param readPath
	 * @throws Exception
	 */
	public static void read(String readPath)throws Exception{
		Document doc=getBuilder().parse(new File(readPath));
		Element root=doc.getDocumentElement();
		NodeList list=root.getChildNodes();
		for (int i=0;i<list.getLength();i++ ) {
			Node node=list.item(i);
			if(node.getNodeType()==Node.ELEMENT_NODE){
				NodeList childlist=node.getChildNodes();
				for (int j = 0; j < childlist.getLength(); j++) {
					Node childNode=childlist.item(j);
					System.out.println(childNode.getNodeName()+":"+childNode.getTextContent());
					
				}
			}
		}
	}
	public static void main(String[] args) throws Exception {
		//XML.writer(SAVE_PATH);
		XML.read(SAVE_PATH);
	}
}