Android中创建与几种解析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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<?xmlversion= "1.0" encoding= "utf-8" ?>
<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<Button
android:id="@+id/btn1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="创建XML文件"
/>
<Button
android:id="@+id/btn2"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="DOM解析XML"
/>
<Button
android:id="@+id/btn3"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="XmlPullParse解析XML"
/>
<TextView
android:id="@+id/result"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
</LinearLayout>

第三步:修改主核心程序XmlDemo.java,代码如下:

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package com.tutor.xml;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
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.NodeList;
import org.xml.sax.SAXException;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import org.xmlpull.v1.XmlPullParserFactory;
import org.xmlpull.v1.XmlSerializer;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.util.Xml;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class XmlDemo extends Activity implements OnClickListener{
private static final StringBOOKS_PATH= "/sdcard/books.xml" ;
private ButtonmButton1,mButton2,mButton3;
private TextViewmTextView;
@Override
public void onCreate(BundlesavedInstanceState){
super .onCreate(savedInstanceState);
setContentView(R.layout.main);
setupViews();
}
//初始化工作
private void setupViews(){
mTextView=(TextView)findViewById(R.id.result);
mButton1=(Button)findViewById(R.id.btn1);
mButton2=(Button)findViewById(R.id.btn2);
mButton3=(Button)findViewById(R.id.btn3);
mButton1.setOnClickListener(this );
mButton2.setOnClickListener(this );
mButton3.setOnClickListener(this );
}
//创建xml文件
private void createXmlFile(){
FilelinceseFile=new File(BOOKS_PATH);
try {
linceseFile.createNewFile();
}catch (IOExceptione){
Log.e("IOException" , "exceptionincreateNewFile()method" );
}
FileOutputStreamfileos=null ;
try {
fileos=new FileOutputStream(linceseFile);
}catch (FileNotFoundExceptione){
Log.e("FileNotFoundException" , "can'tcreateFileOutputStream" );
}
XmlSerializerserializer=Xml.newSerializer();
try {
serializer.setOutput(fileos,"UTF-8" );
serializer.startDocument(null , true );
serializer.startTag(null , "books" );
for ( int i= 0 ;i< 3 ;i++){
serializer.startTag(null , "book" );
serializer.startTag(null , "bookname" );
serializer.text("Android教程" +i);
serializer.endTag(null , "bookname" );
serializer.startTag(null , "bookauthor" );
serializer.text("Frankie" +i);
serializer.endTag(null , "bookauthor" );
serializer.endTag(null , "book" );
}
serializer.endTag(null , "books" );
serializer.endDocument();
serializer.flush();
fileos.close();
}catch (Exceptione){
Log.e("Exception" , "erroroccurredwhilecreatingxmlfile" );
}
Toast.makeText(getApplicationContext(),"创建xml文件成功!" ,Toast.LENGTH_SHORT).show();
}
//dom解析xml文件
private void domParseXML(){
Filefile=new File(BOOKS_PATH);
DocumentBuilderFactorydbf=DocumentBuilderFactory.newInstance();
DocumentBuilderdb=null ;
try {
db=dbf.newDocumentBuilder();
}catch (ParserConfigurationExceptione){
e.printStackTrace();
}
Documentdoc=null ;
try {
doc=db.parse(file);
}catch (SAXExceptione){
e.printStackTrace();
}catch (IOExceptione){
e.printStackTrace();
}
Elementroot=doc.getDocumentElement();
NodeListbooks=root.getElementsByTagName("book" );
Stringres="本结果是通过dom解析:" + "/n" ;
for ( int i= 0 ;i<books.getLength();i++){
Elementbook=(Element)books.item(i);
Elementbookname=(Element)book.getElementsByTagName("bookname" ).item( 0 );
Elementbookauthor=(Element)book.getElementsByTagName("bookauthor" ).item( 0 );
res+="书名:" +bookname.getFirstChild().getNodeValue()+ "" +
"作者:" +bookauthor.getFirstChild().getNodeValue()+ "/n" ;
}
mTextView.setText(res);
}
//xmlPullParser解析xml文件
private void xmlPullParseXML(){
Stringres="本结果是通过XmlPullParse解析:" + "/n" ;
try {
XmlPullParserFactoryfactory=XmlPullParserFactory.newInstance();
XmlPullParserxmlPullParser=factory.newPullParser();
xmlPullParser.setInput(Thread.currentThread().getContextClassLoader()
.getResourceAsStream(BOOKS_PATH),"UTF-8" );
int eventType=xmlPullParser.getEventType();
try {
while (eventType!=XmlPullParser.END_DOCUMENT){
StringnodeName=xmlPullParser.getName();
switch (eventType){
case XmlPullParser.START_TAG:
if ( "bookname" .equals(nodeName)){
res+="书名:" +xmlPullParser.nextText()+ "" ;
}else if ( "bookauthor" .equals(nodeName)){
res+="作者:" +xmlPullParser.nextText()+ "/n" ;
}
break ;
default :
break ;
}
eventType=xmlPullParser.next();
}
}catch (IOExceptione){
e.printStackTrace();
}
}catch (XmlPullParserExceptione){
e.printStackTrace();
}
mTextView.setText(res);
}
//按钮事件响应
public void onClick(Viewv){
if (v==mButton1){
createXmlFile();
}else if (v==mButton2){
domParseXML();
}else if (v==mButton3){
xmlPullParseXML();
}
}
}

package com.tutor.xml;import java.io.File;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;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.NodeList;import org.xml.sax.SAXException;import org.xmlpull.v1.XmlPullParser;import org.xmlpull.v1.XmlPullParserException;import org.xmlpull.v1.XmlPullParserFactory;import org.xmlpull.v1.XmlSerializer;import android.app.Activity;import android.os.Bundle;import android.util.Log;import android.util.Xml;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.TextView;import android.widget.Toast;public class XmlDemo extends Activity implements OnClickListener {   private static final String BOOKS_PATH = "/sdcard/books.xml";private Button mButton1,mButton2,mButton3;private TextView mTextView;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        setupViews();    }    //初始化工作    private void setupViews(){    mTextView = (TextView)findViewById(R.id.result);    mButton1 = (Button)findViewById(R.id.btn1);    mButton2 = (Button)findViewById(R.id.btn2);    mButton3 = (Button)findViewById(R.id.btn3);    mButton1.setOnClickListener(this);    mButton2.setOnClickListener(this);    mButton3.setOnClickListener(this);    }    //创建xml文件    private void createXmlFile(){    File linceseFile = new File(BOOKS_PATH);    try{    linceseFile.createNewFile();    }catch (IOException e) {    Log.e("IOException", "exception in createNewFile() method");}    FileOutputStream fileos = null;    try{    fileos = new FileOutputStream(linceseFile);    }catch (FileNotFoundException  e) {    Log.e("FileNotFoundException", "can't create FileOutputStream");}    XmlSerializer serializer = Xml.newSerializer();    try {            serializer.setOutput(fileos,"UTF-8");            serializer.startDocument(null, true);            serializer.startTag(null, "books");            for(int i = 0; i < 3; i ++){                serializer.startTag(null, "book");                serializer.startTag(null, "bookname");                serializer.text("Android教程" + i);                serializer.endTag(null, "bookname");                serializer.startTag(null, "bookauthor");                serializer.text("Frankie" + i);                serializer.endTag(null, "bookauthor");                serializer.endTag(null, "book");            }                    serializer.endTag(null, "books");            serializer.endDocument();            serializer.flush();            fileos.close();        } catch (Exception e) {        Log.e("Exception","error occurred while creating xml file");        }        Toast.makeText(getApplicationContext(), "创建xml文件成功!", Toast.LENGTH_SHORT).show();    }    //dom解析xml文件    private void domParseXML(){    File file = new File(BOOKS_PATH);    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();       DocumentBuilder db = null;    try {db = dbf.newDocumentBuilder();} catch (ParserConfigurationException e) {e.printStackTrace();}Document doc = null;try {doc = db.parse(file);} catch (SAXException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}Element root = doc.getDocumentElement();NodeList books = root.getElementsByTagName("book");String res = "本结果是通过dom解析:" + "/n";for(int i = 0; i < books.getLength();i++){Element book = (Element)books.item(i);Element bookname = (Element)book.getElementsByTagName("bookname").item(0);Element bookauthor = (Element)book.getElementsByTagName("bookauthor").item(0);res += "书名: " + bookname.getFirstChild().getNodeValue() + " " +       "作者: " + bookauthor.getFirstChild().getNodeValue() + "/n";}mTextView.setText(res);    }      //xmlPullParser解析xml文件    private void xmlPullParseXML(){    String res = "本结果是通过XmlPullParse解析:" + "/n";    try {    XmlPullParserFactory factory = XmlPullParserFactory.newInstance();XmlPullParser xmlPullParser = factory.newPullParser();xmlPullParser.setInput(Thread.currentThread().getContextClassLoader().getResourceAsStream(BOOKS_PATH), "UTF-8");int eventType = xmlPullParser.getEventType();try{while (eventType != XmlPullParser.END_DOCUMENT) {String nodeName = xmlPullParser.getName();switch (eventType) {case XmlPullParser.START_TAG:if("bookname".equals(nodeName)){res += "书名: " + xmlPullParser.nextText() + " ";}else if("bookauthor".equals(nodeName)){res += "作者: " + xmlPullParser.nextText() + "/n";}break;default:break;}eventType = xmlPullParser.next();}} catch (IOException e) {e.printStackTrace();}} catch (XmlPullParserException e) {e.printStackTrace();}mTextView.setText(res);    }    //按钮事件响应public void onClick(View v) {if(v == mButton1){createXmlFile();}else if(v == mButton2){domParseXML();}else if(v == mButton3){xmlPullParseXML();}}}

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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<?xmlversion= "1.0" encoding= "utf-8" ?>
<manifestxmlns:android="http://schemas.android.com/apk/res/android"
package = "com.tutor.xml"
android:versionCode="1"
android:versionName="1.0" >
<applicationandroid:icon="@drawable/icon" android:label= "@string/app_name" >
<activityandroid:name=".XmlDemo"
android:label="@string/app_name" >
<intent-filter>
<actionandroid:name="android.intent.action.MAIN" />
<categoryandroid:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
<uses-sdkandroid:minSdkVersion="7" />
<uses-permissionandroid:name="android.permission.WRITE_EXTERNAL_STORAGE" />
</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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<?xmlversion= '1.0' encoding= 'UTF-8' standalone= 'yes' ?>
<books>
<book>
<bookname>Android教程0 </bookname>
<bookauthor>Frankie0</bookauthor>
</book>
<book>
<bookname>Android教程1 </bookname>
<bookauthor>Frankie1</bookauthor>
</book>
<book>
<bookname>Android教程2 </bookname>
<bookauthor>Frankie2</bookauthor>
</book>
</books>

点击DOM解析XML按钮:

点击XmlPullParse解析XML按钮:

Ok~今天就先讲到这里。thx~

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