XML解析的三种方式

参考：http://blog.csdn.net/liuhe688/article/details/6415593

首先定义一个接口

package com.lei.xml;import java.io.InputStream;import java.util.List;public interface XMLParser {// 解析xml<T> List<T> xmlParse(InputStream is);//构造xml<T> String xmlSerializer(List<T> list);}

1. PULL解析

解析速度快，事件处理，不会预加载整个文档

package com.lei.xml;import java.io.IOException;import java.io.InputStream;import java.io.StringWriter;import java.util.ArrayList;import java.util.List;import org.xmlpull.v1.XmlPullParser;import org.xmlpull.v1.XmlPullParserException;import org.xmlpull.v1.XmlSerializer;import android.util.Xml;public class PullParse implements XMLParser {public static PullParse getInstance() {return new PullParse();}public <T> List<T> xmlParse(InputStream is) {List<Book> list = null;Book book = null;XmlPullParser parser = Xml.newPullParser();// XmlPullParser parser =// XmlPullParserFactory.newInstance().newPullParser();try {parser.setInput(is, "utf-8");int type = parser.getEventType();while (type != XmlPullParser.END_DOCUMENT) {//整个xml结束标签，出口switch (type) {case XmlPullParser.START_DOCUMENT://整个xml开始标签，入口list = new ArrayList<Book>();break;case XmlPullParser.START_TAG://子开始标签if (parser.getName().equals("book")) {book = new Book();} else if (parser.getName().equals("id")) {type = parser.next();book.setId(Integer.parseInt(parser.getText()));} else if (parser.getName().equals("name")) {type = parser.next();book.setName(parser.getText());}break;case XmlPullParser.END_TAG://子结束标签if (parser.getName().equals("book")) {list.add(book);}break;}type = parser.next();}} catch (XmlPullParserException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}return (List<T>) list;}public <T> String xmlSerializer(List<T> list) {List<Book> lists = (List<Book>) list;XmlSerializer serializer = Xml.newSerializer();try {serializer.startDocument("utf-8", true);serializer.setOutput(new StringWriter());serializer.startTag("", "books");for (Book book : lists) {serializer.startTag("", "book");serializer.attribute("", "id", String.valueOf(book.getId()));serializer.startTag("", "name");serializer.text(book.getName());serializer.endTag("", "name");serializer.endTag("", "book");}serializer.endTag("", "books");serializer.endDocument();} catch (IllegalArgumentException e) {e.printStackTrace();} catch (IllegalStateException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}return serializer.toString();}}

2. SAX解析

树形结构，速度款，占用内存少，会预加载整个文档，适用于文档较小。

package com.lei.xml;import java.io.IOException;import java.io.InputStream;import java.util.ArrayList;import java.util.List;import javax.xml.parsers.ParserConfigurationException;import javax.xml.parsers.SAXParser;import javax.xml.parsers.SAXParserFactory;import org.xml.sax.Attributes;import org.xml.sax.SAXException;import org.xml.sax.helpers.DefaultHandler;import com.lei.utils.Logs;public class SaxParse implements XMLParser {public static SaxParse getInstance() {return new SaxParse();}/** * 解析xml */public <T> List<T> xmlParse(InputStream is) {try {SAXParser parser = SAXParserFactory.newInstance().newSAXParser();MyXmlHandler handler = new MyXmlHandler();parser.parse(is, handler);return (List<T>) handler.getBookList();} catch (ParserConfigurationException e) {e.printStackTrace();} catch (SAXException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}return null;}/** * 生成xml */public <T> String xmlSerializer(List<T> list) {return null;}class MyXmlHandler extends DefaultHandler {List<Book> list;Book book;StringBuilder builder;public List<Book> getBookList() {return list;}// 入口，开始@Overridepublic void startDocument() throws SAXException {super.startDocument();Logs.v("startDocument");list = new ArrayList<Book>();builder = new StringBuilder();}// 出口，结束@Overridepublic void endDocument() throws SAXException {super.endDocument();Logs.v("endDocument");}// 开始解析开始标签@Overridepublic void startElement(String uri, String localName, String qName,Attributes attributes) throws SAXException {super.startElement(uri, localName, qName, attributes);Logs.v("startElement  " + "uri " + uri + " localName " + localName+ " qName  " + qName);if ("book".equals(localName)) {book = new Book();}builder.setLength(0);// 每次豆浆builder清空}// 结束标签@Overridepublic void endElement(String uri, String localName, String qName)throws SAXException {super.endElement(uri, localName, qName);Logs.v("endElement  " + "uri " + uri + " localName " + localName+ " qName  " + qName);if ("id".equals(localName)) {book.setId(Integer.parseInt(builder.toString()));} else if ("name".equals(localName)) {book.setName(builder.toString());} else if ("book".equals(localName)) {list.add(book);}}// 获取子标签的内容@Overridepublic void characters(char[] ch, int start, int length)throws SAXException {super.characters(ch, start, length);builder.append(ch, start, length);Logs.v("characters " + new String(ch, start, length));}}}

3.DOM解析

预先加载整个文档，占用内存大，不推荐使用

package com.lei.xml;import java.io.IOException;import java.io.InputStream;import java.util.ArrayList;import java.util.List;import javax.xml.parsers.DocumentBuilder;import javax.xml.parsers.DocumentBuilderFactory;import javax.xml.parsers.ParserConfigurationException;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;public class DomParse implements XMLParser {public static DomParse getInstance(){return new DomParse();}public <T> List<T> xmlParse(InputStream is) {List<Book> list = new ArrayList<Book>();DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();try {DocumentBuilder builder = factory.newDocumentBuilder();Document doc = builder.parse(is);Element element = doc.getElementById("book");NodeList nodeList = element.getChildNodes();Book book = null;for (int i = 0; i < nodeList.getLength(); i++) {Node node = nodeList.item(i);book = new Book();NodeList details = node.getChildNodes();for (int j = 0; j < details.getLength(); j++) {if (node.getLocalName().equals("id")) {book.setId(Integer.parseInt(node.getNodeValue()));} else if (node.getLocalName().equals("name")) {book.setName(node.getNodeValue());}}list.add(book);}} catch (ParserConfigurationException e) {e.printStackTrace();} catch (SAXException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}return (List<T>) list;}public <T> String xmlSerializer(List<T> list) {return null;}}

使用：

在 assets下放了一个books.xml

private void parseXmBySax() {try {InputStream is = getAssets().open("books.xml");List<Book> list = new SaxParse().xmlParse(is);for (Book book : list) {mShowTv.append(book.toString());}} catch (IOException e) {e.printStackTrace();}}private void parseXmByPull() {InputStream is = null;try {is = getAssets().open("books.xml");} catch (IOException e) {e.printStackTrace();}List<Book> list = PullParse.getInstance().xmlParse(is);for (Book book : list) {mShowTv.append(book.toString());}}private void parseXmlByDom() {InputStream is = null;try {is = getAssets().open("books.xml");} catch (IOException e) {e.printStackTrace();}List<Book> list = new SaxParse().xmlParse(is);for (Book book : list) {mShowTv.append(book.toString());}}