Android 创建与解析XML(二)—— Dom方式

时间:2019-01-19
本文章向大家介绍Android 创建与解析XML(二)—— Dom方式,主要包括Android 创建与解析XML(二)—— Dom方式使用实例、应用技巧、基本知识点总结和需要注意事项,具有一定的参考价值,需要的朋友可以参考一下。
               

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