学步园

 

 

使用文件保存数据固然很方便，都是如果现在数据较多的话，管理起来就不方便，所以使用文件保存时，

往往会采用XML文件形式进行数据的保存，那么就要对XML文件进行解析，而DOM解析就是最常用

的一种方式。

 

 

 

在AndroidManifest.xml中配置权限

 

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

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

    package="com.li.dom"

    android:versionCode="1"

    android:versionName="1.0" >

 

    <uses-sdk android:minSdkVersion="10" />

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

 

    <application

        android:icon="@drawable/ic_launcher"

        android:label="@string/app_name" >

        <activity

            android:name=".MyDOMDemo"

            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>

 

</manifest>

 

 

 

在main.xml中：

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

<TableLayout

  xmlns:android="http://schemas.android.com/apk/res/android"

  android:orientation="vertical"

  android:layout_width="fill_parent"

  android:layout_height="fill_parent">

  <TableRow

      android:gravity="center_horizontal"

      android:layout_margin="8dp">

     <TextView

       android:layout_width="fill_parent"

       android:layout_height="wrap_content"

       android:text="姓名：" />

     <EditText

       android:id="@+id/name"

       android:layout_width="fill_parent"

       android:layout_height="wrap_content"

       android:text="李叶文" />

  </TableRow>

  <TableRow

      android:gravity="center_horizontal">

     <TextView

       android:layout_width="fill_parent"

       android:layout_height="wrap_content"

       android:text="邮箱：" />

     <EditText

       android:id="@+id/email"

       android:layout_width="fill_parent"

       android:layout_height="wrap_content"

       android:text="helloliyewen@163.com" />

  </TableRow>

  <TableRow

      android:layout_marginLeft="30dp">

     <Button

       android:id="@+id/but"

       android:layout_width="60dp"

       android:layout_height="wrap_content"

       android:text="保存" />

  </TableRow>

</TableLayout>

 

 

 

在MyDOMDemo.java程序中

 

package com.li.dom;

import java.io.File;

 

import javax.xml.parsers.DocumentBuilder;

import javax.xml.parsers.DocumentBuilderFactory;

import javax.xml.parsers.ParserConfigurationException;

import javax.xml.transform.OutputKeys;

import javax.xml.transform.Transformer;

import javax.xml.transform.TransformerConfigurationException;

import javax.xml.transform.TransformerException;

import javax.xml.transform.TransformerFactory;

import javax.xml.transform.dom.DOMSource;

import javax.xml.transform.stream.StreamResult;

 

import org.w3c.dom.Document;

import org.w3c.dom.Element;

 

import android.app.Activity;

import android.os.Bundle;

import android.os.Environment;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.EditText;

 

public class MyDOMDemo extends Activity {

  private EditText name = null ;

  private EditText email = null ;

  private Button but = null ;

  @Override

  public void onCreate(Bundle savedInstanceState) {

     super.onCreate(savedInstanceState);

     super.setContentView(R.layout.main);

     this.name = (EditText) super.findViewById(R.id.name) ;

     this.email = (EditText) super.findViewById(R.id.email) ;

     this.but = (Button) super.findViewById(R.id.but) ;

     this.but.setOnClickListener(new OnClickListenerImpl()) ;

  }

  private class OnClickListenerImpl implements OnClickListener{

 

     public void onClick(View v) {

       if (!Environment.getExternalStorageState().equals(

            Environment.MEDIA_MOUNTED)) { // 不存在不操作

         return; // 返回到程序的被调用处

       }

       File file = new File(Environment.getExternalStorageDirectory()

            + File.separator + "liyewen" + File.separator

            + "test.xml");  // 要输出文件的路径

       if (!file.getParentFile().exists()) { // 父路径不存在

         file.getParentFile().mkdirs() ;  // 创建父文件夹

       }

       DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance() ;

       DocumentBuilder builder = null ;

       try {

         builder = factory.newDocumentBuilder() ;

       } catch (ParserConfigurationException e) {

         e.printStackTrace();

       }

       Document doc = null ;

       doc = builder.newDocument() ; // 创建一个新的文档

       Element addresslist = doc.createElement_x("addresslist") ;

       Element linkman = doc.createElement_x("linkman") ;

       Element name = doc.createElement_x("name") ;

       Element email = doc.createElement_x("email") ;

       name.appendChild(doc.createTextNode(MyDOMDemo.this.name.getText()

            .toString()));

       email.appendChild(doc.createTextNode(MyDOMDemo.this.email.getText()

            .toString()));

       linkman.appendChild(name) ;

       linkman.appendChild(email) ;

       addresslist.appendChild(linkman) ;

       doc.appendChild(addresslist) ;

       TransformerFactory tf = TransformerFactory.newInstance() ;

       Transformer t = null ;

       try {

         t = tf.newTransformer() ;

       } catch (TransformerConfigurationException e) {

         e.printStackTrace();

       }

       t.setOutputProperty(OutputKeys.ENCODING, "GBK") ;

       DOMSource source = new DOMSource(doc);

       StreamResult result = new StreamResult(file) ;

       try {

         t.transform(source, result) ;

       } catch (TransformerException e) {

         e.printStackTrace();

       }

     }

    

  }

}