Android开发之文件下载，状态时显示下载进度，点击自动安装

在进行软件升级时，需要进行文件下载，在这里实现自定义的文件下载，并在状态栏显示下载进度，下载完成后，点击触发安装。

效果如图：

用于下载文件和显示现在进度的线程类如下：

 package com.channelsoft.ahzyfis.util;

 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.InputStream;
 import java.net.HttpURLConnection;
 import java.net.URL;

 import android.app.Notification;
 import android.app.NotificationManager;
 import android.app.PendingIntent;
 import android.content.Context;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Environment;
 import android.os.Handler;
 import android.os.Message;
 import android.util.Log;
 import android.widget.RemoteViews;
 import android.widget.Toast;

 import com.channelsoft.ahzyfis.AhzyFisActivity;
 import com.channelsoft.ahzyfis.R;

 /**
  *
  * <dl>
  * <dt>AppFileDownUtils.java</dt>
  * <dd>Description: 文件下载</dd>
  * <dd>Copyright: Copyright (C) 2011</dd>
  * <dd>Company: </dd>
  * <dd>CreateDate: 2011-10-19</dd>
  * </dl>
  *
  * @author ZhanHua
  */
 public class AppFileDownUtils extends Thread {

     private Context mContext;
     private Handler mHandler;
     private String mDownloadUrl; // 文件下载url，已做非空检查
     private String mFileName;
     private Message msg;

     private final String APP_FOLDER = "DownDemo"; // sd卡应用目录
     private final String APK_FOLDER = "apkFile"; // 下载apk文件目录

     public static final int MSG_UNDOWN = 0; //未开始下载
     public static final int MSG_DOWNING = 1; // 下载中
     public static final int MSG_FINISH = 1; // 下载完成
     public static final int MSG_FAILURE = 2;// 下载失败

     private NotificationManager mNotifManager;
     private Notification mDownNotification;
     private RemoteViews mContentView; // 下载进度View
     private PendingIntent mDownPendingIntent;

     public AppFileDownUtils(Context context, Handler handler,
             String downloadUrl, String fileName) {
         mContext = context;
         mHandler = handler;
         mDownloadUrl = downloadUrl;
         mFileName = fileName;
         mNotifManager = (NotificationManager) mContext
                 .getSystemService(Context.NOTIFICATION_SERVICE);
         msg = new Message();
     }

     @Override
     public void run() {
         try {
             if (Environment.getExternalStorageState().equals(
                     Environment.MEDIA_MOUNTED)) {
                 Message downingMsg = new Message();
                 downingMsg.what = MSG_DOWNING;
                 mHandler.sendMessage(downingMsg);
                 // SD卡准备好
                 File sdcardDir = Environment.getExternalStorageDirectory();
                 // 文件存放路径： sdcard/DownDemo/apkFile
                 File folder = new File(sdcardDir + File.separator + APP_FOLDER
                         + File.separator + APK_FOLDER);
                 if (!folder.exists()) {
                     //创建存放目录
                     folder.mkdir();
                 }
                 File saveFilePath = new File(folder, mFileName);
                 System.out.println(saveFilePath);
                 mDownNotification = new Notification(
                         android.R.drawable.stat_sys_download, mContext
                                 .getString(R.string.notif_down_file), System
                                 .currentTimeMillis());
                 mDownNotification.flags = Notification.FLAG_ONGOING_EVENT;
                 mDownNotification.flags = Notification.FLAG_AUTO_CANCEL;
                 mContentView = new RemoteViews(mContext.getPackageName(),
                         R.layout.custom_notification);
                 mContentView.setImageViewResource(R.id.downLoadIcon,
                         android.R.drawable.stat_sys_download);
                 mDownPendingIntent = PendingIntent.getActivity(mContext, 0, new Intent(), 0);
                 boolean downSuc = downloadFile(mDownloadUrl, saveFilePath);
                 if (downSuc) {
                     msg.what = MSG_FINISH;
                     Notification notification = new Notification(
                             android.R.drawable.stat_sys_download_done, mContext
                                     .getString(R.string.downloadSuccess),
                             System.currentTimeMillis());
                     notification.flags = Notification.FLAG_ONGOING_EVENT;
                     notification.flags = Notification.FLAG_AUTO_CANCEL;
                     Intent intent = new Intent(Intent.ACTION_VIEW);
                     intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                     intent.setDataAndType(Uri.fromFile(saveFilePath),
                             "application/vnd.android.package-archive");
                     PendingIntent contentIntent = PendingIntent.getActivity(
                             mContext, 0, intent, 0);
                     notification.setLatestEventInfo(mContext, mContext
                             .getString(R.string.downloadSuccess), null,
                             contentIntent);
                     mNotifManager.notify(R.drawable.icon, notification);
                 } else {
                     msg.what = MSG_FAILURE;
                     Notification notification = new Notification(
                             android.R.drawable.stat_sys_download_done, mContext
                                     .getString(R.string.downloadFailure),
                             System.currentTimeMillis());
                     notification.flags = Notification.FLAG_AUTO_CANCEL;
                     PendingIntent contentIntent = PendingIntent.getActivity(
                             mContext, 0, new Intent(), 0);
                     notification.setLatestEventInfo(mContext, mContext
                             .getString(R.string.downloadFailure), null,
                             contentIntent);
                     mNotifManager.notify(R.drawable.icon, notification);
                 }

             } else {
                 Toast.makeText(mContext, Environment.getExternalStorageState(),
                         Toast.LENGTH_SHORT).show();
                 msg.what = MSG_FAILURE;
             }
         } catch (Exception e) {
             Log.e(AhzyFisActivity.TAG, "AppFileDownUtils catch Exception:", e);
             msg.what = MSG_FAILURE;
         } finally {
             mHandler.sendMessage(msg);
         }
     }

     /**
      *
      * Desc:文件下载
      *
      * @param downloadUrl
      *            下载URL
      * @param saveFilePath
      *            保存文件路径
      * @return ture:下载成功 false:下载失败
      */
     public boolean downloadFile(String downloadUrl, File saveFilePath) {
         int fileSize = -1;
         int downFileSize = 0;
         boolean result = false;
         int progress = 0;
         try {
             URL url = new URL(downloadUrl);
             HttpURLConnection conn = (HttpURLConnection) url.openConnection();
             if (null == conn) {
                 return false;
             }
             // 读取超时时间 毫秒级
             conn.setReadTimeout(10000);
             conn.setRequestMethod("GET");
             conn.setDoInput(true);
             conn.connect();
             if (conn.getResponseCode() == HttpURLConnection.HTTP_OK) {
                 fileSize = conn.getContentLength();
                 InputStream is = conn.getInputStream();
                 FileOutputStream fos = new FileOutputStream(saveFilePath);
                 byte[] buffer = new byte[1024];
                 int i = 0;
                 int tempProgress = -1;
                 while ((i = is.read(buffer)) != -1) {
                     downFileSize = downFileSize + i;
                     // 下载进度
                     progress = (int) (downFileSize * 100.0 / fileSize);
                     fos.write(buffer, 0, i);

                     synchronized (this) {
                         if (downFileSize == fileSize) {
                             // 下载完成
                             mNotifManager.cancel(R.id.downLoadIcon);
                         } else if (tempProgress != progress) {
                             // 下载进度发生改变，则发送Message
                             mContentView.setTextViewText(R.id.progressPercent,
                                     progress + "%");
                             mContentView.setProgressBar(R.id.downLoadProgress,
                                     100, progress, false);
                             mDownNotification.contentView = mContentView;
                             mDownNotification.contentIntent = mDownPendingIntent;
                             mNotifManager.notify(R.id.downLoadIcon,
                                     mDownNotification);
                             tempProgress = progress;
                         }
                     }
                 }
                 fos.flush();
                 fos.close();
                 is.close();
                 result = true;
             } else {
                 result = false;
             }
         } catch (Exception e) {
             result = false;
             Log.e(AhzyFisActivity.TAG, "downloadFile catch Exception:", e);
         }
         return result;
     }
 }

在下载过程中，如果需要和主线程（UI Main Thread）通信，及时让主线程了解下载进度和状态，可用通过Handle向主线程发送Message

进度条显示的布局文件如下：

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout
   android:id="@+id/custom_notification"
   xmlns:android="http://schemas.android.com/apk/res/android"
   android:orientation="horizontal"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent">
     <ImageView
         android:id="@+id/downLoadIcon"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_marginLeft="5dip"
         android:layout_gravity="center_vertical"
         />
     <TextView
         android:layout_height="fill_parent"
         android:layout_width="wrap_content"
         android:layout_marginLeft="5dip"
         android:text="@string/downloadProgress"
         android:gravity="center_vertical"
         />
     <ProgressBar
         android:id="@+id/downLoadProgress"
         style="?android:attr/progressBarStyleHorizontal"
         mce_style="?android:attr/progressBarStyleHorizontal"
         android:layout_marginLeft="10dip"
         android:layout_width="150dip"
         android:layout_height="wrap_content"
         android:layout_gravity="center_vertical"
         />
     <TextView
         android:id="@+id/progressPercent"
         android:layout_height="fill_parent"
         android:layout_width="wrap_content"
         android:layout_marginLeft="5dip"
         android:gravity="center_vertical"
         />
 </LinearLayout>