android中使用SAX, DOM, 或者pull 来解析XML文档

<?xml version="1.0" encoding="UTF-8"?> <persons>     <person id="1">       <name>张三</name>       <age>22</age>     </person>     <person id="2">       <name>李四</name>       <age>23</age>     </person></persons>

定义一个名为Person的javaBean用于存放上面解析出来的xml内容：

public class Person{    private Integer id;    private String name;    private Short age;    public Integer getId(){        return id;    }    public void setId(Integer id){        this.id = id;    }    public String getName(){        return name;    }    public void setName(String name){        this.name = name;    }    public Short getAge(){        return age;    }    public void setAge(Short age){        this.age = age;    }}

(1)使用SAX读取XML文件;它采用的是事件驱动，并不需要解析完整个文档，速度快并且占用内存少。需要为SAX提供实现ContentHandler接口的类。

import java.util.ArrayList;import java.util.List;import org.xml.sax.Attributes;import org.xml.sax.SAXException;import org.xml.sax.helpers.DefaultHandler;import com.sinber.domain.Person;public class PersonDefaultHandler extends DefaultHandler{private List<Person> persons;private Person person ; //记录当前personprivate String perTag; //记录前一个标签的名称 /** * 重写父类的开始文档方法。用于初始化 */@Overridepublic void startDocument()throws SAXException {persons = new ArrayList<Person>();}@Overridepublic void startElement(String uri, String localName, String qName, Attributes attributes)throws SAXException {if("person".equals(localName)){Integer id = new Integer(attributes.getValue(0)); //取idperson = new Person();person.setId(id);}perTag = localName;} /**参数： * ch 整个XML字符串 * start 节点值在整个XML字符串中的索引位置 * length 节点值的长度 */@Overridepublic void characters(char[] ch, int start, int length)throws SAXException {if(perTag!=null){String data = new String(ch,start,length);if("name".equals(perTag)){person.setName(data);}else if("age".equals(perTag)){person.setAge(new Short(data));}}}@Overridepublic void endElement(String uri, String localName, String qName)throws SAXException {if("person".equals(localName)){persons.add(person);person = null;}perTag = null;}public List<Person> getPersons() {return persons;}}

SAXPerson.java

import java.io.InputStream;import java.util.List;import javax.xml.parsers.SAXParser;import javax.xml.parsers.SAXParserFactory;import com.sinber.domain.Person;public class SAXPerson{    public static List<Person> getPerson() throws Exception{        //通过类装载器获取文件        InputStream inStream = SAXPersonService.class.getClassLoader().getResourceAsStream("person.xml");        SAXParserFactory factory = SAXParserFactory.newInstance();         SAXParser saxParser = factory.newSAXParser();        PersonDefaultHandler handler = new PersonDefaultHandler();        saxParser.parse(inStream, handler);        inStream.close();                return handler.getPersons();    }}

(2)DOM解析XML文件时，会将XML文件的所有内容读取到内存中，然后允许您使用DOM API遍历XML树、检索所需的数据。

　　DOMPerson.java

import java.io.InputStream;import java.util.ArrayList;import java.util.List;import javax.xml.parsers.DocumentBuilder;import javax.xml.parsers.DocumentBuilderFactory;import org.w3c.dom.Document;import org.w3c.dom.Element;import org.w3c.dom.Node;import org.w3c.dom.NodeList;import com.sinber.domain.Person;public class DOMPerson {public static List<Person> getPerson() throws Exception{List<Person> pers = new ArrayList<Person>();InputStream inStream = SAXPersonService.class.getClassLoader().getResourceAsStream("person.xml");DocumentBuilderFactory factory =DocumentBuilderFactory.newInstance();DocumentBuilder builder = factory.newDocumentBuilder();Document dom = builder.parse(inStream);Element root = dom.getDocumentElement();NodeList persons = root.getElementsByTagName("person");for(int i=0;i<persons.getLength();i++){ Element personNode =(Element)persons.item(i);Person person = new Person();person.setId(new Integer(personNode.getAttribute("id")));NodeList childNodes = personNode.getChildNodes();for(int j=0;j<childNodes.getLength();j++;{Node childNode = childNodes.item(j);if(childNode.getNodeType()==Node.ELEMENT_NODE){Element element = (Element)childNode;if("name".equals(childNode.getNodeName())){ person.setName(new String(element.getFirstChild().getNodeValue()));}else if("age".equals(childNode.getNodeName())){person.setAge(new Short(element.getFirstChild().getNodeValue()));}}}pers.add(person);}inStream.close();return pers;}}

(3)使用Pull解析器读取XML文件

　　PullPerson.java

import java.io.File;import java.io.FileOutputStream;import java.io.InputStream;import java.util.ArrayList;import java.util.List;import org.xmlpull.v1.XmlPullParser;import org.xmlpull.v1.XmlSerializer;import android.os.Environment;import android.util.Xml;import com.sinber.domain.Person;public class PullPerson {public static void save(List<Person> persons) throws Exception{XmlSerializer serializer = Xml.newSerializer();File file = new File(Environment.getExternalStorageDirectory(),"person.xml");FileOutputStream outStream = new FileOutputStream(file);serializer.setOutput(outStream,"UTF-8");serializer.startDocument("UTF-8", true);serializer.startTag("", "persons");for(Person person:persons){serializer.startTag("", "person"); //person serializer.attribute("", "id", ""+person.getId());serializer.startTag("", "name"); //nameserializer.text(person.getName());serializer.endTag("", "name"); //name serializer.startTag("", "age"); //ageserializer.text(person.getAge().toString());serializer.endTag("", "age");//age serializer.endTag("", "person"); //person}serializer.endTag("", "persons");serializer.endDocument();outStream.close();}public static List<Person> getPersons() throws Exception{List<Person> persons = null;Person person = null;XmlPullParser parser= Xml.newPullParser();InputStream inStream = PullPersonService.class.getClassLoader().getResourceAsStream("person.xml");parser.setInput(inStream, "UTF-8");int eventType = parser.getEventType();//触发第一个事件while(eventType!=XmlPullParser.END_DOCUMENT){switch(eventType){case XmlPullParser.START_DOCUMENT: persons = new ArrayList<Person>();break;case XmlPullParser.START_TAG: //开始元素事件if("person".equals(parser.getName())){person = new Person();person.setId(new Integer(parser.getAttributeValue(0)));}else if(person!=null){if("name".equals(parser.getName())){person.setName(parser.nextText());}else if("age".equals(parser.getName())){person.setAge(new Short(parser.nextText()));}} break;caseXmlPullParser.END_TAG: //结束元素事件if("person".equals(parser.getName())){persons.add(person);person = null;} break; default: break;}eventType = parser.next();}return persons;}}

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