<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:orientation="vertical"
  tools:context="com.oak.d3_xml.MainActivity">
 
  <TextView
    android:id="@+id/tv"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Hello World!" />
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="生成"
    android:id="@+id/bt_create"/>
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="讀取"
    android:id="@+id/bt_read"/>
</LinearLayout>

package com.oak.d3_xml;
 
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
 
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
 
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
 
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
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;
 
 
public class MainActivity extends AppCompatActivity {
  private TextView textView;//用于展示讀取xml的內(nèi)容
  private Button bt_create;//用于創(chuàng)建xml文件
  private Button bt_read;//用于讀取xml文件
  private File file;//xml文件路徑
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    file = new File(getFilesDir(),"languages.xml");//獲取到xml文件
    textView = (TextView) findViewById(R.id.tv);//拿到textView控件
    bt_create = (Button) findViewById(R.id.bt_create);//拿到創(chuàng)建按鈕
    bt_read = (Button) findViewById(R.id.bt_read);//拿到讀取按鈕
 
    bt_create.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        //這里利用的是dom對xml進(jìn)行操作的
        //實(shí)例化一個(gè)DocmentBuilderFactory，調(diào)用其靜態(tài)方法獲取
        DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
        try {
          //實(shí)例化一個(gè)DocumentBuilder
          DocumentBuilder builder = builderFactory.newDocumentBuilder();
          //實(shí)例化一個(gè)xml文件
          Document newxml = builder.newDocument();
          //創(chuàng)建一個(gè)根標(biāo)簽
          Element languages = newxml.createElement("languages");
          //為其設(shè)置屬性
          languages.setAttribute("cat","it");
          //for循壞3次，分別創(chuàng)建出三個(gè)標(biāo)簽，每個(gè)標(biāo)簽都包含內(nèi)容
          for (int i=0;i<3;i++){
            //創(chuàng)建languages的子標(biāo)簽lan
            Element lan = newxml.createElement("lan");
            //設(shè)置屬性
            lan.setAttribute("id",i+"");
            //創(chuàng)建lan的子標(biāo)簽
            Element name = newxml.createElement("name");
            //設(shè)置內(nèi)容
            name.setTextContent("Java"+i);
            //創(chuàng)建lan的子標(biāo)簽
            Element ide = newxml.createElement("ide");
            //設(shè)置內(nèi)容
            ide.setTextContent("Eclipse"+i);
            //將name和ide分別加入lan這個(gè)標(biāo)簽中
            lan.appendChild(name);
            lan.appendChild(ide);
            //將lan將入languages標(biāo)簽中
            languages.appendChild(lan);
          }
          //將languages加入到xml文件中
          newxml.appendChild(languages);
          //實(shí)例化Transformer工廠
          TransformerFactory transformerFactory = TransformerFactory.newInstance();
          //獲取到Transformer
          Transformer transformer = transformerFactory.newTransformer();
          //設(shè)置輸出格式
          transformer.setOutputProperty("encoding","UTF-8");
          //設(shè)置輸出流
          OutputStream os = new FileOutputStream(file);
          //將文件寫出
          transformer.transform(new DOMSource(newxml),new StreamResult(os));
          Toast.makeText(getApplicationContext(),"生成成功",Toast.LENGTH_SHORT).show();
        } catch (ParserConfigurationException e) {
          e.printStackTrace();
        } catch (TransformerConfigurationException e) {
          e.printStackTrace();
        } catch (FileNotFoundException e) {
          e.printStackTrace();
        } catch (TransformerException e) {
          e.printStackTrace();
        }
      }
    });
    bt_read.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        //獲取到DocumentBuilder的工廠實(shí)例化
        DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
        try {
          //拿到DocumentBuilder
          DocumentBuilder builder = builderFactory.newDocumentBuilder();
          //解析xml文件
          Document xml = builder.parse(file);
          //獲取其根標(biāo)簽
          Element languages = xml.getDocumentElement();
          //根據(jù)子標(biāo)簽進(jìn)行查找，返回的是一個(gè)list集合
          NodeList list = languages.getElementsByTagName("lan");
          textView.setText("");//將textView中的內(nèi)容置空
          for (int i=0; i<list.getLength(); i++){
            //獲取到子標(biāo)簽lan
            Element lan = (Element) list.item(i);
            //獲取到他的屬性
            String id = lan.getAttribute("id");
            //獲取到他的子標(biāo)簽name的內(nèi)容
            String name = lan.getElementsByTagName("name").item(0).getTextContent();
            //獲取到他的子標(biāo)簽ide的內(nèi)容
            String ide = lan.getElementsByTagName("ide").item(0).getTextContent();
            //顯示到textView中
            textView.append(id+"\n"+name+"\n"+ide+"\n");
          }
        } catch (ParserConfigurationException e) {
          e.printStackTrace();
        } catch (SAXException e) {
          e.printStackTrace();
        } catch (IOException e) {
          e.printStackTrace();
        }
 
      }
    });
  }
}