Android App实现应用内部自动更新的最基本方法示例

这只是初步的实现，并没有加入自动编译等功能。需要手动更改更新的xml文件和最新的apk。   
共涉及到四个文件！
一、客户端
AndroidUpdateTestActivity：程序首页
main.xml：首页布局
Update：更新类
softupdate_progress：更新等待界面

Updage

package majier.test; 
 
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.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; 
 
import android.app.alertDialog; 
import android.app.Dialog; 
import android.app.alertDialog.Builder; 
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.os.Message; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.widget.ProgressBar; 
import android.widget.Toast; 
 
public class Update { 
  private static final int DOWNLOAD = 1; 
  private static final int DOWNLOAD_FINISH = 2; 
  private static final int CONNECT_FAILED = 0; 
  private static final int CONNECT_SUCCESS = 1; 
  HashMap mHashMap; 
  private String mSavePath; 
  private int progress; 
  private boolean cancelUpdate = false; 
  private Context mContext; 
  private ProgressBar mProgress; 
  private Dialog mDownloadDialog; 
  private String mXmlPath; // 服务器更新xml存放地址 
 
  public Update(Context context, String xmlPath, String savePath) { 
    this.mContext = context; 
    this.mXmlPath = xmlPath; 
    this.mSavePath = savePath; 
  } 
 
  private Handler mHandler = new Handler() { 
    public void handleMessage(Message msg) { 
      switch (msg.what) { 
      case DOWNLOAD: 
 mProgress.setProgress(progress); 
 break; 
      case DOWNLOAD_FINISH: 
 installApk(); 
 break; 
      default: 
 break; 
      } 
    }; 
  }; 
 
   
  public void checkUpdate() { 
    new Thread(new Runnable() { 
      @Override 
      public void run() { 
 try { 
   URL url = new URL(mXmlPath); 
   HttpURLConnection conn = (HttpURLConnection) url 
.openConnection(); 
   conn.setConnectTimeout(5000); 
   InputStream inStream = conn.getInputStream(); 
   mHashMap = parseXml(inStream); 
   Message msg = new Message(); 
   msg.what = CONNECT_SUCCESS; 
   handler.sendMessage(msg); 
 } catch (Exception e) { 
   Message msg = new Message(); 
   msg.what = CONNECT_FAILED; 
   handler.sendMessage(msg); 
 } 
      } 
    }).run(); 
  } 
 
   
  Handler handler = new Handler() { 
    @Override 
    public void handleMessage(Message msg) { 
      super.handleMessage(msg); 
      switch (msg.what) { 
      case CONNECT_FAILED: 
 Toast.makeText(mContext, "访问服务器失败！", Toast.LENGTH_SHORT).show(); 
 break; 
      case CONNECT_SUCCESS: 
 if (null != mHashMap) { 
   int serviceCode = Integer.valueOf(mHashMap.get("version")); 
   if (serviceCode > getVersionCode(mContext)) { 
     showNoticeDialog(); 
   } 
 } 
 break; 
      } 
    } 
  }; 
 
   
  private int getVersionCode(Context context) { 
    int versionCode = 0; 
    try { 
      versionCode = context.getPackageManager().getPackageInfo( 
   mContext.getPackageName(), 0).versionCode; 
    } catch (NameNotFoundException e) { 
      e.printStackTrace(); 
    } 
    return versionCode; 
  } 
 
   
  private void showNoticeDialog() { 
    alertDialog.Builder builder = new Builder(mContext); 
    builder.setTitle("软件更新"); 
    builder.setMessage("检测到新版本，是否更新？"); 
    builder.setPositiveButton("更新", 
 new onClickListener() { 
   @Override 
   public void onClick(DialogInterface dialog, int which) { 
     dialog.dismiss(); 
     showDownloadDialog(); 
   } 
 }); 
 
    builder.setNegativeButton("取消", 
 new onClickListener() { 
   @Override 
   public void onClick(DialogInterface dialog, int which) { 
     dialog.dismiss(); 
   } 
 }); 
    Dialog noticeDialog = builder.create(); 
    noticeDialog.show(); 
  } 
 
   
  private void showDownloadDialog() { 
    alertDialog.Builder builder = new Builder(mContext); 
    builder.setTitle("正在更新"); 
    final LayoutInflater inflater = LayoutInflater.from(mContext); 
    View v = inflater.inflate(R.layout.softupdate_progress, null); 
    mProgress = (ProgressBar) v.findViewById(R.id.update_progress); 
    builder.setView(v); 
    builder.setNegativeButton("取消下载", 
 new onClickListener() { 
   @Override 
   public void onClick(DialogInterface dialog, int which) { 
     dialog.dismiss(); 
     cancelUpdate = true; 
   } 
 }); 
    mDownloadDialog = builder.create(); 
    mDownloadDialog.show(); 
    downloadApk(); 
  } 
 
   
  private void downloadApk() { 
    new downloadApkThread().start(); 
  } 
 
   
  private class downloadApkThread extends Thread { 
    @Override 
    public void run() { 
      try { 
 if (Environment.getExternalStorageState().equals( 
     Environment.MEDIA_MOUNTED)) { 
 
   URL url = new URL(mHashMap.get("url")); 
   HttpURLConnection conn = (HttpURLConnection) url 
.openConnection(); 
   conn.connect(); 
   int length = conn.getContentLength(); 
   InputStream is = conn.getInputStream(); 
 
   File file = new File(mSavePath); 
   if (!file.exists()) { 
     file.mkdir(); 
   } 
   File apkFile = new File(mSavePath, mHashMap.get("name")); 
   FileOutputStream fos = new FileOutputStream(apkFile); 
   int count = 0; 
   byte buf[] = new byte[1024]; 
   do { 
     int numread = is.read(buf); 
     count += numread; 
     progress = (int) (((float) count / length) * 100); 
     mHandler.sendEmptyMessage(DOWNLOAD); 
     if (numread <= 0) { 
mHandler.sendEmptyMessage(DOWNLOAD_FINISH); 
break; 
     } 
 
     fos.write(buf, 0, numread); 
   } while (!cancelUpdate); 
   fos.close(); 
   is.close(); 
 } 
      } catch (MalformedURLException e) { 
 e.printStackTrace(); 
      } catch (IOException e) { 
 e.printStackTrace(); 
      } 
 
      mDownloadDialog.dismiss(); 
    } 
  }; 
   
   
  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); 
  } 
 
  private HashMap parseXml(InputStream inStream) 
      throws Exception { 
    HashMap hashMap = new HashMap(); 
    // 实例化一个文档构建器工厂 
    documentBuilderFactory factory = documentBuilderFactory.newInstance(); 
    // 通过文档构建器工厂获取一个文档构建器 
    documentBuilder builder = factory.newdocumentBuilder(); 
    // 通过文档通过文档构建器构建一个文档实例 
    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 j = 0; j < childNodes.getLength(); j++) { 
      // 遍历子节点 
      Node childNode = (Node) childNodes.item(j); 
      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; 
  } 
} 

AndroidUpdateTestActivity

package majier.test; 
 
import android.app.Activity; 
import android.os.Bundle; 
import android.os.Environment; 
 
public class AndroidUpdateTestActivity extends Activity { 
   
  @Override 
  public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main); 
    update(); 
  } 
   
  private void update() { 
    String sdpath = Environment.getExternalStorageDirectory() + "/"; 
    String mSavePath = sdpath + "boiler/"; 
    Update updateManager = new Update(this, 
 "http://localhost:8011/abcd.xml", mSavePath); 
    updateManager.checkUpdate(); 
  } 
} 

main.xml

softupdate_progress.xml

每次生成新的apk前，需要修改系统的版本号。

修改version code 和version name。上面的代码可以看出，系统是根据version code来判断是否需要更新的。version name作为一个版本名称。
这里我建议version code从10开始，这样方面名称修改（1.1、1.2）。
修改完成后，生成系统。然后将apk文件放在服务端的文件下。

二、服务端
服务端主要是建立一个网址供用户下载apk。在IIS上新建网站

http://localhost:8011/。将更新文件和更新的xml放在目录下。 

version.xml格式

 
  12 
  BoilerAndroid_1.1 
  http://192.168.0.33:8011/boilerandroid.apk 
 

version对应着新程序的version code；
name随便起名；
url对应apk的下载路径。

在这里有可能会遇见一个问题，访问url路径时IIS报错。主要是因为IIS并不认识apk，不知道如何处理。
这里我们在IIS中新增安卓程序的MIME类型，来使apk支持下载。
在“IIS管理器”中查看所建立的网站——MIME类型——添加。
文件扩展名：.apk
MIME类型：application/vnd.android.package-archive

这样就可以下载了。
目前只是一个简单的自动更新程序。我们可以看出，其中版本号需要自己填写，而且要与xml中的对应，apk需要生成后放在更新网址下。
这么的人为操作，很容易造成失误。因此，接下来我们要研究下自动发布更新版本，并且版本号与svn对应，在提交svn后，自动改变程序的版本号。