xml02 XML编程(CRUD)增删查改

XML解析技术概述

Demo2.java

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;

public class Demo2 {
	public static void main(String args[])throws Exception {
		//1.创建工程
		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
		
		
		//2.得到dom解析器
		DocumentBuilder builder = factory.newDocumentBuilder();
		
		//3.解析xml文档,得到代表文档的document
		Document document = builder.parse("src/book.xml");
	}
}

xml解析技术概述和使用Jaxp对xml文档进行dom解析

package cn.lysine;

import org.junit.Test;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

//使用dom方式对xml文档进行 增删查改 	CRUD
public class Demo3 {

	// 读取xml文档中；<书名>java就业培训中心</书名> 节点的值
	@Test
	public void read1() throws Exception {
		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
		DocumentBuilder builder = factory.newDocumentBuilder();
		Document document = builder.parse("src/book.xml");

		NodeList list = document.getElementsByTagName("书名");
		Node node = list.item(1);
		String content = node.getTextContent();
		System.out.println(content);      //输出 java就业培训中心 
	}
	//得到xml中标签属性的值
	@Test
	public void read2() throws Exception {
		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
		DocumentBuilder builder = factory.newDocumentBuilder();
		Document document = builder.parse("src/book.xml");

		// 得到根结点
		Node root = document.getElementsByTagName("书架").item(0);

		list(root);
	}

	private void list(Node node) {
		System.out.println(node.getNodeName());
		NodeList list = node.getChildNodes();
		for(int i = 0; i <list.getLength(); i++ ){
			Node childe = list.item(i);
			list(childe);
		}
	}
	
	//得到xml文档中标签属性的值：<书名 name="xxxx">java就业培训教材</书名>
	@Test
	public void read3() throws Exception{
		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
		DocumentBuilder builder = factory.newDocumentBuilder();
		Document document = builder.parse("src/book.xml");
		
		Element bookname = (Element)document.getElementsByTagName("书名").item(0);
		String value = bookname.getAttribute("name");
		System.out.println(value);
	}    //输出 xxxx
}

import java.io.FileOutputStream;
import java.io.IOException;

import org.junit.Test;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

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

//使用dom方式对xml文档进行 增删查改 	CRUD
public class Demo3 {

	// 读取xml文档中；<书名>java就业培训中心</书名> 节点的值
	@Test
	public void read1() throws Exception {
		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
		DocumentBuilder builder = factory.newDocumentBuilder();
		Document document = builder.parse("src/book.xml");

		NodeList list = document.getElementsByTagName("书名");
		Node node = list.item(0);
		String content = node.getTextContent();
		System.out.println(content);
	}
	//得到xml中标签属性的值
	@Test
	public void read2() throws Exception {
		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
		DocumentBuilder builder = factory.newDocumentBuilder();
		Document document = builder.parse("src/book.xml");

		// 得到根结点
		Node root = document.getElementsByTagName("书架").item(0);

		list(root);
	}

	private void list(Node node) {
		System.out.println(node.getNodeName());
		NodeList list = node.getChildNodes();
		for(int i = 0; i <list.getLength(); i++ ){
			Node childe = list.item(i);
			list(childe);
		}
	}
	
	//得到xml文档中标签属性的值：<书名 name="xxxx">java就业培训教材</书名>
	@Test
	public void read3() throws Exception{
		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
		DocumentBuilder builder = factory.newDocumentBuilder();
		Document document = builder.parse("src/book.xml");
		
		Element bookname = (Element)document.getElementsByTagName("书名").item(0);
		String value = bookname.getAttribute("name");
		System.out.println(value);
	}
	
	//向xml文档中添加节点：<售价>59.00元</售价>
	@Test
	public void add() throws Exception{
		
		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
		DocumentBuilder builder = factory.newDocumentBuilder();
		Document document = builder.parse("src/book.xml");
		//创建节点
		Element price = document.createElement("售价");
		price.setTextContent("59.00元");
		
		//得到参考节点
		Element refNode = (Element) document.getElementsByTagName("售价").item(0);
		
		//得到要挂崽的节点                 把创建的节点挂到第一本书上
		Element book = (Element)document.getElementsByTagName("书").item(0);		
		
		//往book节点的指定位置插崽
		book.insertBefore(price,refNode);
		
		//把更新后内存写回到xml文档
		TransformerFactory tffactory = TransformerFactory.newInstance();
		Transformer tf = tffactory.newTransformer();
		tf.transform(new DOMSource(document), new StreamResult(new FileOutputStream("src/book.xml")));
		
	}
	
	
	//add    向xml文档中添加节点：<书名>java就业培训教程</书名> 上添加name=“xxxx”属性
	@Test
	public void addAttr() throws Exception{
		
		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
		DocumentBuilder builder = factory.newDocumentBuilder();
		Document document = builder.parse("src/book.xml");
		
		Element bookname = (Element) document.getElementsByTagName("书名").item(0);
		bookname.setAttribute("name", "xxxxx");
		
		//把更新后内存写回到xml文档
		TransformerFactory tffactory = TransformerFactory.newInstance();
		Transformer tf = tffactory.newTransformer();
		tf.transform(new DOMSource(document),new StreamResult(new FileOutputStream("src/book.xml")));
	}
	
	//删除整个xml
	@Test
	public void delete1() throws Exception{
		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
		DocumentBuilder builder = factory.newDocumentBuilder();
		Document document = builder.parse("src/book.xml");
		
		//得到要删除的结点
		Element e = (Element) document.getElementsByTagName("售价").item(0);
				
		//得到要删除的结点的爸爸
		Element book = (Element) document.getElementsByTagName("书").item(0);
		
		//爸爸再删崽
		book.removeChild(e);
		
		//把更新后内存写回到xml文档
		TransformerFactory tffactory = TransformerFactory.newInstance();
		Transformer tf = tffactory.newTransformer();
		tf.transform(new DOMSource(document),new StreamResult(new FileOutputStream("src/book.xml")));
	
	}
	public void delete2() throws Exception{
		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
		DocumentBuilder builder = factory.newDocumentBuilder();
		Document document = builder.parse("src/book.xml");
		
		//得到要删除的结点
		Element e = (Element) document.getElementsByTagName("售价").item(0);
		e.getParentNode().getParentNode().getParentNode().removeChild(e.getParentNode().getParentNode());
		

		//把更新后内存写回到xml文档
		TransformerFactory tffactory = TransformerFactory.newInstance();
		Transformer tf = tffactory.newTransformer();
		tf.transform(new DOMSource(document),new StreamResult(new FileOutputStream("src/book.xml")));
		
	}
	
	//update  更新
	public void update()throws ParserConfigurationException, SAXException, IOException,Exception{
		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
		DocumentBuilder builder = factory.newDocumentBuilder();
		Document document = builder.parse("src/book.xml");
		
		//得到要更新的结点	
		Element e = (Element) document.getElementsByTagName("售价").item(0);
		e.setTextContent("109元");
		
		//把更新后内存写回到xml文档
		TransformerFactory tffactory = TransformerFactory.newInstance();
		Transformer tf = tffactory.newTransformer();
		tf.transform(new DOMSource(document),new StreamResult(new FileOutputStream("src/book.xml")));
	}
}