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:

<?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>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns: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:

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):

<?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>

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.tutor.xml"
      android:versionCode="1"
      android:versionName="1.0">
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".XmlDemo"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
    <uses-sdk android:minSdkVersion="7" />
	<uses-permission android: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:

<?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>

<?xml version='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~