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>