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>