Android 中创建与解析XML的方法

大家好今天我今天给大家讲解一下android中xml的创建以及一些解析xml的常用方法。首先是创建，我们用XmlSerializer这个类来创建一个xml文件，其次是解析xml文件，常用的有dom, sax, XmlPullParser等方法，由于sax代码有点复杂，本节只讲解一下dom与XmlPullParser解析，sax我将会在下一节单独讲解,至于几种解析xml的优缺点我就不再讲述了。

为了方便理解，我做了一个简单的Demo。首先首界面有三个按钮，点击第一个按钮会在sdcard目录下创建一个books.xml文件,另外两个按钮分别是调用dom与XmlPullParser方法解析xml文件，并将结果显示在一个TextView里。大家可以按照我的步骤一步步来:

第一步:新建一个Android工程,命名为XmlDemo.

第二步:修改main.xml布局文件，代码如下:

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01<?xmlversion="1.0"encoding="utf-8"?> 

02<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android" 

03android:orientation="vertical" 

04android:layout_width="fill_parent" 

05android:layout_height="fill_parent" 

06> 

07<Button 

08android:id="@+id/btn1" 

09android:layout_width="fill_parent" 

10android:layout_height="wrap_content" 

11android:text="创建XML文件" 

12/> 

13<Button 

14android:id="@+id/btn2" 

15android:layout_width="fill_parent" 

16android:layout_height="wrap_content" 

17android:text="DOM解析XML" 

18/> 

19<Button 

20android:id="@+id/btn3" 

21android:layout_width="fill_parent" 

22android:layout_height="wrap_content" 

23android:text="XmlPullParse解析XML" 

24/> 

25<TextView 

26android:id="@+id/result" 

27android:layout_width="fill_parent" 

28android:layout_height="wrap_content" 

29/> 

30</LinearLayout>

第三步:修改主核心程序XmlDemo.java,代码如下:

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001package com.tutor.xml; 

002import java.io.File; 

003import java.io.FileNotFoundException; 

004import java.io.FileOutputStream; 

005import java.io.IOException; 

006import javax.xml.parsers.DocumentBuilder; 

007import javax.xml.parsers.DocumentBuilderFactory; 

008import javax.xml.parsers.ParserConfigurationException; 

009import org.w3c.dom.Document; 

010import org.w3c.dom.Element; 

011import org.w3c.dom.NodeList; 

012import org.xml.sax.SAXException; 

013import org.xmlpull.v1.XmlPullParser; 

014import org.xmlpull.v1.XmlPullParserException; 

015import org.xmlpull.v1.XmlPullParserFactory; 

016import org.xmlpull.v1.XmlSerializer; 

017import android.app.Activity; 

018import android.os.Bundle; 

019import android.util.Log; 

020import android.util.Xml; 

021import android.view.View; 

022import android.view.View.OnClickListener; 

023import android.widget.Button; 

024import android.widget.TextView; 

025import android.widget.Toast; 

026public class XmlDemo extendsActivity implementsOnClickListener { 

027  

028private static final String BOOKS_PATH ="/sdcard/books.xml"; 

029private Button mButton1,mButton2,mButton3; 

030private TextView mTextView; 

031@Override 

032public void onCreate(Bundle savedInstanceState) { 

033super.onCreate(savedInstanceState); 

034setContentView(R.layout.main); 

035setupViews(); 

036} 

037//初始化工作 

038private void setupViews(){ 

039mTextView = (TextView)findViewById(R.id.result); 

040mButton1 = (Button)findViewById(R.id.btn1); 

041mButton2 = (Button)findViewById(R.id.btn2); 

042mButton3 = (Button)findViewById(R.id.btn3); 

043mButton1.setOnClickListener(this); 

044mButton2.setOnClickListener(this); 

045mButton3.setOnClickListener(this); 

046} 

047//创建xml文件 

048private void createXmlFile(){ 

049File linceseFile = newFile(BOOKS_PATH); 

050try{ 

051linceseFile.createNewFile(); 

052}catch(IOException e) { 

053Log.e("IOException","exception in createNewFile() method"); 

054} 

055FileOutputStream fileos = null; 

056try{ 

057fileos = newFileOutputStream(linceseFile); 

058}catch(FileNotFoundException e) { 

059Log.e("FileNotFoundException","can't create FileOutputStream"); 

060} 

061XmlSerializer serializer = Xml.newSerializer(); 

062try { 

063serializer.setOutput(fileos,"UTF-8"); 

064serializer.startDocument(null,true); 

065serializer.startTag(null,"books"); 

066for(inti = 0; i <3; i ++){ 

067serializer.startTag(null,"book"); 

068serializer.startTag(null,"bookname"); 

069serializer.text("Android教程"+ i); 

070serializer.endTag(null,"bookname"); 

071serializer.startTag(null,"bookauthor"); 

072serializer.text("Frankie"+ i); 

073serializer.endTag(null,"bookauthor"); 

074serializer.endTag(null,"book"); 

075} 

076  

077serializer.endTag(null,"books"); 

078serializer.endDocument(); 

079serializer.flush(); 

080fileos.close(); 

081} catch(Exception e) { 

082Log.e("Exception","error occurred while creating xml file"); 

083} 

084Toast.makeText(getApplicationContext(),"创建xml文件成功!", Toast.LENGTH_SHORT).show(); 

085} 

086//dom解析xml文件 

087private void domParseXML(){ 

088File file = newFile(BOOKS_PATH); 

089DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); 

090DocumentBuilder db = null; 

091try { 

092db = dbf.newDocumentBuilder(); 

093} catch(ParserConfigurationException e) { 

094e.printStackTrace(); 

095} 

096Document doc = null; 

097try { 

098doc = db.parse(file); 

099} catch(SAXException e) { 

100e.printStackTrace(); 

101} catch(IOException e) { 

102e.printStackTrace(); 

103} 

104Element root = doc.getDocumentElement(); 

105NodeList books = root.getElementsByTagName("book"); 

106String res = "本结果是通过dom解析:"+ "/n"; 

107for(inti = 0; i < books.getLength();i++){ 

108Element book = (Element)books.item(i); 

109Element bookname = (Element)book.getElementsByTagName("bookname").item(0); 

110Element bookauthor = (Element)book.getElementsByTagName("bookauthor").item(0); 

111res += "书名: "+ bookname.getFirstChild().getNodeValue() + " "+ 

112"作者: " + bookauthor.getFirstChild().getNodeValue() + "/n"; 

113} 

114  

115mTextView.setText(res); 

116} 

117  

118//xmlPullParser解析xml文件 

119private void xmlPullParseXML(){ 

120String res = "本结果是通过XmlPullParse解析:"+ "/n"; 

121try { 

122XmlPullParserFactory factory = XmlPullParserFactory.newInstance(); 

123XmlPullParser xmlPullParser = factory.newPullParser(); 

124  

125xmlPullParser.setInput(Thread.currentThread().getContextClassLoader() 

126.getResourceAsStream(BOOKS_PATH), "UTF-8"); 

127  

128int eventType = xmlPullParser.getEventType(); 

129  

130try{ 

131while (eventType != XmlPullParser.END_DOCUMENT) { 

132String nodeName = xmlPullParser.getName(); 

133switch (eventType) { 

134case XmlPullParser.START_TAG: 

135if("bookname".equals(nodeName)){ 

136res += "书名: "+ xmlPullParser.nextText() + " "; 

137}elseif("bookauthor".equals(nodeName)){ 

138res += "作者: "+ xmlPullParser.nextText() + "/n"; 

139} 

140break; 

141default: 

142break; 

143} 

144eventType = xmlPullParser.next(); 

145} 

146} catch(IOException e) { 

147e.printStackTrace(); 

148} 

149} catch(XmlPullParserException e) { 

150e.printStackTrace(); 

151} 

152  

153mTextView.setText(res); 

154} 

155//按钮事件响应 

156public void onClick(View v) { 

157if(v == mButton1){ 

158createXmlFile(); 

159}elseif(v == mButton2){ 

160domParseXML(); 

161}elseif(v == mButton3){ 

162xmlPullParseXML(); 

163} 

164} 

165}

第四步:由于我们在Sd卡上新建了文件，需要增加权限，如下代码(第16行):

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01<?xmlversion="1.0"encoding="utf-8"?> 

02<manifestxmlns:android="http://schemas.android.com/apk/res/android" 

03package="com.tutor.xml" 

04android:versionCode="1" 

05android:versionName="1.0"> 

06<applicationandroid:icon="@drawable/icon"android:label="@string/app_name"> 

07<activityandroid:name=".XmlDemo" 

08android:label="@string/app_name"> 

09<intent-filter> 

10<actionandroid:name="android.intent.action.MAIN"/> 

11<categoryandroid:name="android.intent.category.LAUNCHER"/> 

12</intent-filter> 

13</activity> 

14</application> 

15<uses-sdkandroid:minSdkVersion="7"/> 

16<uses-permissionandroid:name="android.permission.WRITE_EXTERNAL_STORAGE"/> 

17</manifest>

第五步:运行上述工程，查看效果:

启动首界面:

点击创建XML文件按钮,生成books.xml文件

books.xml内容如下:

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01<?xmlversion='1.0'encoding='UTF-8'standalone='yes'?> 

02<books> 

03<book> 

04<bookname>Android教程0</bookname> 

05<bookauthor>Frankie0</bookauthor> 

06</book> 

07<book> 

08<bookname>Android教程1</bookname> 

09<bookauthor>Frankie1</bookauthor> 

10</book> 

11<book> 

12<bookname>Android教程2</bookname> 

13<bookauthor>Frankie2</bookauthor> 

14</book> 

15</books>

点击DOM解析XML按钮:

点击XmlPullParse解析XML按钮: