Android 创建与解析XML（二）—— Dom方式

1. Dom概述

Dom方式创建XML，应用了标准xml构造器 javax.xml.parsers.DocumentBuilder 来创建 XML 文档，需要导入以下内容

javax.xml.parsers

javax.xml.parsers.DocumentBuilder 

javax.xml.parsers.DocumentBuilderFactory 

javax.xml.parsers.ParserConfigurationException;

javax.xml.transform

javax.xml.transform.TransformerFactory 

javax.xml.transform.Transformer 

javax.xml.transform.dom.DOMSource 

javax.xml.transform.stream.StreamResult 

javax.xml.transform.OutputKeys;

javax.xml.transform.TransformerFactoryConfigurationError;

javax.xml.transform.TransformerConfigurationException;

javax.xml.transform.TransformerException;

org.w3c.dom 

org.w3c.dom.Document;

org.w3c.dom.Element;

org.w3c.dom.Node;

org.w3c.dom.DOMException;

org.w3c.dom.NodeList;

org.xml.sax.SAXException;

sdk源码查看路径（google code）

创建和解析xml的效果图：

2、Dom 创建 XML

Dom，借助 javax.xml.parsers.DocumentBuilder，可以创建 org.w3c.dom.Document 对象。

使用来自 DocumentBuilderFactory 的 DocumentBuilder 对象在 Android 设备上创建与解析 XML 文档。您将使用 XML pull 解析器的扩展来解析 XML 文档。

Code

	/** Dom方式，创建 XML  */
	public String domCreateXML() {
		String xmlWriter = null;
		
		Person []persons = new Person[3];		// 创建节点Person对象
		persons[0] = new Person(1, "sunboy_2050", "http://blog.csdn.net/sunboy_2050");
		persons[1] = new Person(2, "baidu", "http://www.baidu.com");
		persons[2] = new Person(3, "google", "http://www.google.com");
		
		try {
			DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
			DocumentBuilder builder = factory.newDocumentBuilder();
			Document doc = builder.newDocument();
			
			Element eleRoot = doc.createElement("root");
			eleRoot.setAttribute("author", "homer");
			eleRoot.setAttribute("date", "2012-04-26");
			doc.appendChild(eleRoot);
			
			int personsLen = persons.length;
			for(int i=0; i<personsLen; i++) {
				Element elePerson = doc.createElement("person");
				eleRoot.appendChild(elePerson);
				
				Element eleId = doc.createElement("id");
				Node nodeId = doc.createTextNode(persons[i].getId() + "");
				eleId.appendChild(nodeId);
				elePerson.appendChild(eleId);

				Element eleName = doc.createElement("name");
				Node nodeName = doc.createTextNode(persons[i].getName());
				eleName.appendChild(nodeName);
				elePerson.appendChild(eleName);

				Element eleBlog = doc.createElement("blog");
				Node nodeBlog = doc.createTextNode(persons[i].getBlog());
				eleBlog.appendChild(nodeBlog);
				elePerson.appendChild(eleBlog);
			}
			
			
			Properties properties = new Properties();
			properties.setProperty(OutputKeys.INDENT, "yes");
			properties.setProperty(OutputKeys.MEDIA_TYPE, "xml");
			properties.setProperty(OutputKeys.VERSION, "1.0");
			properties.setProperty(OutputKeys.ENCODING, "utf-8");
			properties.setProperty(OutputKeys.METHOD, "xml");
			properties.setProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
			
			TransformerFactory transformerFactory = TransformerFactory.newInstance();
			Transformer transformer = transformerFactory.newTransformer();
			transformer.setOutputProperties(properties);
			
			DOMSource domSource = new DOMSource(doc.getDocumentElement());
			OutputStream output = new ByteArrayOutputStream();
			StreamResult result = new StreamResult(output);
			transformer.transform(domSource, result);
			
			xmlWriter = output.toString();
			
		} catch (ParserConfigurationException e) {		// factory.newDocumentBuilder
			e.printStackTrace();
		} catch (DOMException e) {						// doc.createElement
			e.printStackTrace();
		} catch (TransformerFactoryConfigurationError e) {		// TransformerFactory.newInstance
			e.printStackTrace();
		} catch (TransformerConfigurationException e) {		// transformerFactory.newTransformer
			e.printStackTrace();
		} catch (TransformerException e) {				// transformer.transform
			e.printStackTrace();
		} catch (Exception e) {
			e.printStackTrace();
		}
		
		savedXML(fileName, xmlWriter.toString());
		
		return xmlWriter.toString();
	}

运行结果：

3、Dom 解析 XML

Dom方式，解析XML是创建XML的逆过程，主要用到了builder.parse(is)进行解析，然后通过Tag、NodeList、Element、childNotes等得到Element和Node属性或值。

Code

	/** Dom方式，解析 XML  */
	public String domResolveXML() {
		StringWriter xmlWriter = new StringWriter();
		
		InputStream is= readXML(fileName);
		try {
			DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
			DocumentBuilder builder = factory.newDocumentBuilder();
			Document doc = builder.parse(is);

			doc.getDocumentElement().normalize();
			NodeList nlRoot = doc.getElementsByTagName("root");
			Element eleRoot = (Element)nlRoot.item(0);
			String attrAuthor = eleRoot.getAttribute("author");
			String attrDate = eleRoot.getAttribute("date");
			xmlWriter.append("root").append("\t\t");
			xmlWriter.append(attrAuthor).append("\t");
			xmlWriter.append(attrDate).append("\n");
			
			NodeList nlPerson = eleRoot.getElementsByTagName("person");
			int personsLen = nlPerson.getLength();
			Person []persons = new Person[personsLen];
			for(int i=0; i<personsLen; i++) {
				Element elePerson = (Element) nlPerson.item(i);		// person节点
				Person person = new Person();						// 创建Person对象
				
				NodeList nlId = elePerson.getElementsByTagName("id");
				Element eleId = (Element)nlId.item(0);
				String id = eleId.getChildNodes().item(0).getNodeValue();
				person.setId(Integer.parseInt(id));
				
				NodeList nlName = elePerson.getElementsByTagName("name");
				Element eleName = (Element)nlName.item(0);
				String name = eleName.getChildNodes().item(0).getNodeValue();
				person.setName(name);
				
				NodeList nlBlog = elePerson.getElementsByTagName("blog");
				Element eleBlog = (Element)nlBlog.item(0);
				String blog = eleBlog.getChildNodes().item(0).getNodeValue();
				person.setBlog(blog);
				
				xmlWriter.append(person.toString()).append("\n");
				persons[i] = person;
			}
			
		} catch (ParserConfigurationException e) {		// factory.newDocumentBuilder
			e.printStackTrace();
		} catch (SAXException e) {		// builder.parse
			e.printStackTrace();
		} catch (IOException e) {		// builder.parse
			e.printStackTrace();
		} catch (Exception e) {
			e.printStackTrace();
		}
		
		return xmlWriter.toString();
	}

运行结果：

4、Person类

Person类，是创建xml的单位实例，基于Java面向对象定义的一个类

public class Person {
	private int id;
	private String name;
	private String blog;
	
	public Person() {
		this.id = -1;
		this.name = "";
		this.blog = "";
	}

	public Person(int id, String name, String blog) {
		this.id = id;
		this.name = name;
		this.blog = blog;
	}
	
	public Person(Person person) {
		this.id = person.id;
		this.name = person.name;
		this.blog = person.blog;
	}

	public Person getPerson(){
		return this;
	}
	
	public void setId(int id) {
		this.id = id;
	}
	
	public int getId(){
		return this.id;
	}
	
	public void setName(String name) {
		this.name = name;
	}

	public String getName() {
		return this.name;
	}

	public void setBlog(String blog) {
		this.blog = blog;
	}

	public String getBlog() {
		return this.blog;
	}

	public String toString() {
		return "Person \nid = " + id + "\nname = " + name + "\nblog = " + blog + "\n";
	}
}

代码下载

参考推荐：

org.w3c.dom

javax.xml.parsers

javax.xml.transform

dom创建xml

java dom创建xml