/**
* 將圖片文件保存到SD卡的根目錄下
*
* 雖然確定SD卡的路徑是可以直接使用"/sdcard"的，但在實(shí)際開(kāi)發(fā)中建議使用：android.os.Environment.getExternalStorageDirectory()
* 方法獲得SD卡的路徑，這樣一旦系統(tǒng)改變了路徑，應(yīng)用程序會(huì)立刻獲得最新的SD卡的路徑，這樣做會(huì)使程序更健壯。
*/
public void writeToSD() {
    try {
      //創(chuàng)建用于將圖片保存到SD卡上的FileOutputStream對(duì)象
      FileOutputStream fos = new FileOutputStream(android.os.Environment.getExternalStorageDirectory() + "/image.jpg");
      //打開(kāi)assets目錄下的image.jpg文件，并返回InputStream對(duì)象
      InputStream is = getResources().getAssets().open("image.jpg");
      //定義一個(gè)byte數(shù)組，用來(lái)保存每次向SD卡中文件寫(xiě)入的數(shù)據(jù)，最多8k
      byte[] buffer = new byte[8192];
      int count = 0;
      //循環(huán)寫(xiě)入數(shù)據(jù)
      while((count = is.read(buffer)) != -1)
      {
        fos.write(buffer, 0, count);
      }
      fos.close();
      is.close();
      Toast.makeText(this, "已成功將圖片保存在SD卡中", Toast.LENGTH_SHORT).show();
    } catch (Exception e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
}
/**
* 從SD卡中讀取圖片文件
* @throws IOException
*/
public void readFromSD() throws IOException{
    //指定SD卡中的圖像文件名
    String fileName = android.os.Environment.getExternalStorageState() + "image.jpg";
    //判斷文件圖片是否存在
    if (!new File(fileName).exists()) {
      Toast.makeText(this, "沒(méi)有要找的圖片文件，未裝入", Toast.LENGTH_SHORT).show();
      return;
    }
    image = (ImageView) findViewById(R.id.image);
    FileInputStream fis = new FileInputStream(fileName);
    //從文件的輸入流裝載Bimap對(duì)象
    Bitmap bitmap = BitmapFactory.decodeStream(fis);
    image.setImageBitmap(bitmap);
    fis.close();
}

<!-- 獲取寫(xiě)權(quán)限 -->
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

<?xml version="1.0" encoding="utf-8"?>
<products>
  <product>
    <id>1</id>
    <name>電腦</name>
    <price>3088</price>
  </product>
  <product>
    <id>2</id>
    <name>微波爐</name>
    <price>2500</price>
  </product>
  <product>
    <id>3</id>
    <name>洗衣機(jī)</name>
    <price>1088</price>
  </product>
</products>

package com.example.data_io_xmltojava;
public class Product {
  int id;
  String name;
  int price;
  public int getId() {
    return id;
  }
  public void setId(int id) {
    this.id = id;
  }
  public String getName() {
    return name;
  }
  public void setName(String name) {
    this.name = name;
  }
  public int getPrice() {
    return price;
  }
  public void setPrice(int price) {
    this.price = price;
  }
}

package com.example.data_io_xmltojava;
import java.util.ArrayList;
import java.util.List;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
public class XML2Product extends DefaultHandler {
  List<Product> products;
  Product product;
  StringBuffer sb = new StringBuffer();
  public List<Product> getProduct() {
    return products;
  }
  /**
   * 開(kāi)始分析XML文件
   */
  @Override
  public void startDocument() throws SAXException {
    // 開(kāi)始分析XML文件，創(chuàng)建list對(duì)象用于保存分析完的product對(duì)象
    products = new ArrayList<Product>();
    super.startDocument();
  }
  /**
   * 開(kāi)始分析XML中的標(biāo)簽
   */
  @Override
  public void startElement(String uri, String localName, String qName,
      Attributes attributes) throws SAXException {
    if (localName.equals("product")) {
      // 如果開(kāi)始分析的是<product>標(biāo)簽，創(chuàng)建一個(gè)product對(duì)象
      product = new Product();
    }
    super.startElement(uri, localName, qName, attributes);
  }
  /**
   * 分析完了XML中的標(biāo)簽
   * 使用sb中的值為product對(duì)象中的屬性賦值
   */
  @Override
  public void endElement(String uri, String localName, String qName)
      throws SAXException {
    if (localName.equals("product")) {
      // 處理完<product>標(biāo)簽后，將product對(duì)象添加到products中
      products.add(product);
    } else if (localName.equals("id")) {
      // 設(shè)置id屬性值
      product.setId(Integer.parseInt(sb.toString().trim()));
      // 將保存標(biāo)簽內(nèi)容的緩存區(qū)清空
      sb.setLength(0);
    } else if (localName.equals("name")) {
      product.setName(sb.toString().trim());
      sb.setLength(0);
    } else if (localName.equals("price")) {
      product.setPrice(Integer.parseInt(sb.toString().trim()));
      sb.setLength(0);
    }
    super.endElement(uri, localName, qName);
  }
  /**
   * 分析完了XML文件
   */
  @Override
  public void endDocument() throws SAXException {
    super.endDocument();
  }
  /**
   * 處理SAX讀取到的XML文件中的內(nèi)容
   */
  @Override
  public void characters(char[] ch, int start, int length)
      throws SAXException {
    // 將SAX掃描到的內(nèi)容保存到sb變量中
    sb.append(ch, start, length);
    super.characters(ch, start, length);
  }
}

package com.example.data_io_xmltojava;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
import org.xml.sax.SAXException;
import android.os.Bundle;
import android.app.Activity;
import android.app.AlertDialog;
import android.util.Xml;
import android.view.Menu;
public class MainActivity extends Activity {
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    // 獲得 /res/raw/products.xml文件中InputStream對(duì)象
    InputStream is = getResources().openRawResource(R.raw.products);
    XML2Product xml2product = new XML2Product();
    try {
      // 開(kāi)始分析products.xml文件（解析）
      android.util.Xml.parse(is, Xml.Encoding.UTF_8, xml2product);
    } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } catch (SAXException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
    // 將轉(zhuǎn)換后得到的java對(duì)象的內(nèi)容輸出
    List<Product> products = xml2product.getProduct();
    String msg = "total" + products.size() + "\n";
    for (Product product : products) {
      msg += "id:" + product.getId() + "產(chǎn)品名：" + product.getName() + "價(jià)格"
          + product.getPrice() + "\n";
    }
    new AlertDialog.Builder(this).setTitle("產(chǎn)品信息").setMessage(msg)
        .setPositiveButton("關(guān)閉", null).show();
  }
  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
  }
}