XML的解析DOM

发布时间：2020-12-16 06:25:26 所属栏目：百科来源：网络整理

导读：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.ParserConfigur

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

[java] 
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   print 
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 /**Dom方式，创建XML*/
 publicStringdomCreateXML(){
 StringxmlWriter=null;
 
 Person[]persons=newPerson[3];//创建节点Person对象
 persons[0]=newPerson(1,"sunboy_2050","http://blog.csdn.net/sunboy_2050");
1]=newPerson(2,"baidu","http://www.baidu.com");
2]=newPerson(3,"google","http://www.google.com");
 
 try{
 DocumentBuilderFactoryfactory=DocumentBuilderFactory.newInstance();
 DocumentBuilderbuilder=factory.newDocumentBuilder();
 Documentdoc=builder.newDocument();
 ElementeleRoot=doc.createElement("root");
 eleRoot.setAttribute("author","homer");
 eleRoot.setAttribute("date","2012-04-26");
 doc.appendChild(eleRoot);
 intpersonsLen=persons.length;
 for(inti=0;i<personsLen;i++){
 ElementelePerson=doc.createElement("person");
 eleRoot.appendChild(elePerson);
 ElementeleId=doc.createElement("id");
 NodenodeId=doc.createTextNode(persons[i].getId()+"");
 eleId.appendChild(nodeId);
 elePerson.appendChild(eleId);
 ElementeleName=doc.createElement("name");
 NodenodeName=doc.createTextNode(persons[i].getName());
 eleName.appendChild(nodeName);
 elePerson.appendChild(eleName);
 ElementeleBlog=doc.createElement("blog");
 NodenodeBlog=doc.createTextNode(persons[i].getBlog());
 eleBlog.appendChild(nodeBlog);
 elePerson.appendChild(eleBlog);
 }
 Propertiesproperties=newProperties();
 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");
 TransformerFactorytransformerFactory=TransformerFactory.newInstance();
 Transformertransformer=transformerFactory.newTransformer();
 transformer.setOutputProperties(properties);
 DOMSourcedomSource=newDOMSource(doc.getDocumentElement());
 OutputStreamoutput=newByteArrayOutputStream();
 StreamResultresult=newStreamResult(output);
 transformer.transform(domSource,result);
 xmlWriter=output.toString();
 }catch(ParserConfigurationExceptione){//factory.newDocumentBuilder
 e.printStackTrace();
 }catch(DOMExceptione){//doc.createElement
 }catch(TransformerFactoryConfigurationErrore){//TransformerFactory.newInstance
 }catch(TransformerConfigurationExceptione){//transformerFactory.newTransformer
 }catch(TransformerExceptione){//transformer.transform
 }catch(Exceptione){
 savedXML(fileName,xmlWriter.toString());
 returnxmlWriter.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

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publicStringdomResolveXML(){
StringWriterxmlWriter=newStringWriter();
InputStreamis=readXML(fileName);
Documentdoc=builder.parse(is);
doc.getDocumentElement().normalize();
NodeListnlRoot=doc.getElementsByTagName("root");
ElementeleRoot=(Element)nlRoot.item(0);
StringattrAuthor=eleRoot.getAttribute("author");
StringattrDate=eleRoot.getAttribute("date");
xmlWriter.append("root").append("tt");
xmlWriter.append(attrAuthor).append("t");
xmlWriter.append(attrDate).append("n");
NodeListnlPerson=eleRoot.getElementsByTagName("person");
intpersonsLen=nlPerson.getLength();
Person[]persons=newPerson[personsLen];
ElementelePerson=(Element)nlPerson.item(i);//person节点
Personperson=newPerson();//创建Person对象
NodeListnlId=elePerson.getElementsByTagName("id");
ElementeleId=(Element)nlId.item(0);
Stringid=eleId.getChildNodes().item(0).getNodeValue();
person.setId(Integer.parseInt(id));
NodeListnlName=elePerson.getElementsByTagName("name");
ElementeleName=(Element)nlName.item( Stringname=eleName.getChildNodes().item(0).getNodeValue();
person.setName(name);
NodeListnlBlog=elePerson.getElementsByTagName("blog");
ElementeleBlog=(Element)nlBlog.item( Stringblog=eleBlog.getChildNodes().item( person.setBlog(blog);
xmlWriter.append(person.toString()).append("n");
persons[i]=person;
}
//factory.newDocumentBuilder
e.printStackTrace();
}catch(SAXExceptione){//builder.parse
}catch(IOExceptione){ }catch(Exceptione){
returnxmlWriter.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

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publicclassPerson{

privateintid;
privateStringname;
privateStringblog;
publicPerson(){
this.id=-1;
this.name="";
this.blog="";
publicPerson(intid,Stringname,Stringblog){
this.id=id;
this.name=name;
this.blog=blog;
publicPerson(Personperson){
this.id=person.id;
this.name=person.name;
this.blog=person.blog;
publicPersongetPerson(){
returnthis;
publicvoidsetId(intid){
publicintgetId(){
returnthis.id;
publicvoidsetName(Stringname){
this.name=name;
publicStringgetName(){
returnthis.name;
publicvoidsetBlog(Stringblog){
publicStringgetBlog(){
returnthis.blog;
publicStringtoString(){
return"Personnid="+id+"nname="+name+"nblog="+blog+"n";
}

（编辑：李大同）

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