Android软件自动更新实现代码

<update>
 <version>2</version>
 <name>baiduxinwen.apk</name>
 <url>http://gdown.baidu.com/data/wisegame/e5f5c3b8e59401c8/baiduxinwen.apk</url>
</update>

package com.xiaowu.news.update;

import java.io.InputStream;
import java.util.HashMap;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class ParseXmlService {
 public HashMap<String, String> parseXml (InputStream inStream) throws Exception{
 HashMap<String, String> hashMap = new HashMap<String, String>();
 //创建DocumentBuilderFactory，该对象将创建DocumentBuilder。
 DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
 //创建DocumentBuilder，DocumentBuilder将实际进行解析以创建Document对象
 DocumentBuilder builder = factory.newDocumentBuilder();
 //解析该文件以创建Document对象
 Document document = builder.parse(inStream);
 //获取XML文件根节点 
 Element root = document.getDocumentElement();
 //获得所有子节点
 NodeList childNodes = root.getChildNodes();
 for(int i = 0; i < childNodes.getLength(); i++) {
  Node childNode = (Node) childNodes.item(i);
  if(childNode.getNodeType() == Node.ELEMENT_NODE) {
  Element childElement = (Element) childNode;
  //版本号 
  if("version".equals(childElement.getNodeName())) {
   hashMap.put("version", childElement.getFirstChild().getNodeValue());
  //软件名称 
  } else if("name".equals(childElement.getNodeName())) {
   hashMap.put("name", childElement.getFirstChild().getNodeValue());
  //下载地址
  } else if("url".equals(childElement.getNodeName())) {
   hashMap.put("url", childElement.getFirstChild().getNodeValue());
  }
  }
  
 }
 return hashMap;
 }
}

package com.xiaowu.news.update;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;

import javax.net.ssl.HttpsURLConnection;

import android.app.AlertDialog;
import android.app.AlertDialog.Builder;
import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.DialogInterface.OnClickListener;
import android.content.pm.PackageManager.NameNotFoundException;
import android.net.Uri;
import android.os.Environment;
import android.os.Handler;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.ProgressBar;
import android.widget.Toast;

import com.xiaowu.news.R;

/**
 * 
 * @author wwj
 * @date 2012/11/17
 * 实现软件更新的管理类
 */
public class UpdateManager {
 
 //下载中...
 private static final int DOWNLOAD = 1;
 //下载完成
 private static final int DOWNLOAD_FINISH = 2;
 //保存解析的XML信息
 HashMap<String , String> mHashMap;
 //下载保存路径
 private String mSavePath;
 //记录进度条数量
 private int progress;
 //是否取消更新
 private boolean cancelUpdate = false;
 //上下文对象
 private Context mContext;
 //进度条
 private ProgressBar mProgressBar;
 //更新进度条的对话框
 private Dialog mDownloadDialog;
 
 
 private Handler mHandler = new Handler() {
 public void handleMessage(android.os.Message msg) {
  switch(msg.what){
  //下载中。。。
  case DOWNLOAD:
  //更新进度条
  System.out.println(progress);
  mProgressBar.setProgress(progress);
  break;
  //下载完成
  case DOWNLOAD_FINISH:
  // 安装文件
  installApk();
  break;
  }
 };
 };


 public UpdateManager(Context context) {
 super();
 this.mContext = context;
 }
 
 
 /**
 * 检测软件更新
 */
 public void checkUpdate() {
 if (isUpdate()) {
  //显示提示对话框
  showNoticeDialog();
 } else {
  Toast.makeText(mContext, R.string.soft_update_no, Toast.LENGTH_SHORT).show();
 }
 
 }
 
 private void showNoticeDialog() {
 // TODO Auto-generated method stub
 //构造对话框
 AlertDialog.Builder builder = new Builder(mContext);
 builder.setTitle(R.string.soft_update_title);
 builder.setMessage(R.string.soft_update_info);
 //更新
 builder.setPositiveButton(R.string.soft_update_updatebtn, new OnClickListener() {
  
  @Override
  public void onClick(DialogInterface dialog, int which) {
  // TODO Auto-generated method stub
  dialog.dismiss();
  // 显示下载对话框
  showDownloadDialog();
  }
 });
 // 稍后更新
 builder.setNegativeButton(R.string.soft_update_later, new OnClickListener() {
  
  @Override
  public void onClick(DialogInterface dialog, int which) {
  // TODO Auto-generated method stub
  dialog.dismiss();
  }
 });
 Dialog noticeDialog = builder.create();
 noticeDialog.show();
 }
 
 private void showDownloadDialog() {
 // 构造软件下载对话框
 AlertDialog.Builder builder = new Builder(mContext);
 builder.setTitle(R.string.soft_updating);
 // 给下载对话框增加进度条
 final LayoutInflater inflater = LayoutInflater.from(mContext);
 View view = inflater.inflate(R.layout.softupdate_progress, null);
 mProgressBar = (ProgressBar) view.findViewById(R.id.update_progress);
 builder.setView(view);
 builder.setNegativeButton(R.string.soft_update_cancel, new OnClickListener() {
  
  @Override
  public void onClick(DialogInterface dialog, int which) {
  // TODO Auto-generated method stub
  dialog.dismiss();
  // 设置取消状态
  cancelUpdate = true;
  }
 });
 mDownloadDialog = builder.create();
 mDownloadDialog.show();
 //下载文件
 downloadApk();
 }
 
 /**
 * 下载APK文件
 */
 private void downloadApk() {
 // TODO Auto-generated method stub
 // 启动新线程下载软件
 new DownloadApkThread().start();
 }


 /**
 * 检查软件是否有更新版本
 * @return
 */
 public boolean isUpdate() {
 // 获取当前软件版本
 int versionCode = getVersionCode(mContext);
 //把version.xml放到网络上，然后获取文件信息
 InputStream inStream = ParseXmlService.class.getClassLoader().getResourceAsStream("version.xml");
 // 解析XML文件。 由于XML文件比较小，因此使用DOM方式进行解析
 ParseXmlService service = new ParseXmlService();
 try {
  mHashMap = service.parseXml(inStream);
 } catch (Exception e) {
  // TODO: handle exception
  e.printStackTrace();
 }
 if(null != mHashMap) {
  int serviceCode = Integer.valueOf(mHashMap.get("version"));
  //版本判断
  if(serviceCode > versionCode) {
  return true;
  }
 }
 return false;
 }

 /**
 * 获取软件版本号
 * @param context
 * @return
 */
 private int getVersionCode(Context context) {
 // TODO Auto-generated method stub
 int versionCode = 0;

 // 获取软件版本号，对应AndroidManifest.xml下android:versionCode
 try {
  versionCode = context.getPackageManager().getPackageInfo(
   "com.xiaowu.news", 0).versionCode;
 } catch (NameNotFoundException e) {
  // TODO Auto-generated catch block
  e.printStackTrace();
 }
 return versionCode;
 }
 
 /**
 * 下载文件线程
 * @author Administrator
 *
 */
 private class DownloadApkThread extends Thread {
 @Override
 public void run() {
  try
  {
  //判断SD卡是否存在，并且是否具有读写权限
  if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED))
  {
   // 获取SDCard的路径
   String sdpath = Environment.getExternalStorageDirectory() + "/";
   mSavePath = sdpath + "download";
   URL url = new URL(mHashMap.get("url"));
   // 创建连接
   HttpURLConnection conn = (HttpURLConnection) url.openConnection();
   conn.connect();
   // 获取文件大小
   int length = conn.getContentLength();
   // 创建输入流
   InputStream is = conn.getInputStream();

   File file = new File(mSavePath);
   // 如果文件不存在，新建目录
   if (!file.exists())
   {
   file.mkdir();
   }
   File apkFile = new File(mSavePath, mHashMap.get("name"));
   FileOutputStream fos = new FileOutputStream(apkFile);
   int count = 0;
   // 缓存
   byte buf[] = new byte[1024];
   // 写入到文件中
   do
   {
   int numread = is.read(buf);
   count += numread;
   // 计算进度条的位置
   progress = (int) (((float) count / length) * 100);
   // 更新进度
   mHandler.sendEmptyMessage(DOWNLOAD);
   if (numread <= 0)
   {
    // 下载完成
    mHandler.sendEmptyMessage(DOWNLOAD_FINISH);
    break;
   }
   // 写入文件
   fos.write(buf, 0, numread);
   } while (!cancelUpdate);//点击取消就停止下载
   fos.close();
   is.close();
  }
  } catch (MalformedURLException e)
  {
  e.printStackTrace();
  } catch (IOException e)
  {
  e.printStackTrace();
  }
  // 取消下载对话框显示
  mDownloadDialog.dismiss();
 }
 }
 
 /**
 * 安装APK文件
 */
 private void installApk()
 {
 File apkfile = new File(mSavePath, mHashMap.get("name"));
 if (!apkfile.exists())
 {
  return;
 }
 Intent i = new Intent(Intent.ACTION_VIEW);
 i.setDataAndType(Uri.parse("file://" + apkfile.toString()), "application/vnd.android.package-archive");
 mContext.startActivity(i);
 }
}