Android 中创建与解析XML的方法

2
Android Java C/C++ Go ico 22377 次浏览
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:
<?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 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):
<?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:
Android 中创建与解析XML的方法

点击创建XML文件按钮,生成books.xml文件
Android 中创建与解析XML的方法
books.xml内容如下:
<?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:
Android 中创建与解析XML的方法

点击XmlPullParse解析XML按钮:
Android 中创建与解析XML的方法
请尽量让自己的答案能够对别人有帮助

5个答案

默认排序 按投票排序
0

Thank you for sharing the codes.  tcs lol

0

学习了,刚好用到谢谢啦

0
很好,多谢分享
0

学习了

0

很好,刚刚试了一下,运行成功了