android下载类DownloadManager

SDK在API Level 9中加入了DownloadManager服务，可以将长时间的下载任务交给系统，完全由系统管理。

直接看实例代码：

import java.io.File;

import android.app.DownloadManager;
import android.app.DownloadManager.Request;
import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.database.sqlite.SQLiteDatabase;
import android.net.Uri;
import android.os.Environment;
import android.os.IBinder;
import android.util.Log;

import com.quma.core.Attribute;
import com.quma.db.DaoManager;
import com.quma.db.DatabaseOpenHelper;
import com.quma.db.DatabaseOpenHelper.WritableHandler;
import com.quma.db.entity.Upgrade;
import com.quma.webservice.ServiceManager;
import com.quma.webservice.constants.UpgradeStatus;

/**
 * 
 * @company qq:176291935
 * @author iaiai
 * @version
 * @date 2015-5-27 下午12:15:41
 */
public class UpgradeService extends Service {

    private File updateDir; //目录

    private File updateFile;    //文件

    private String fileName;    //文件名

    /** 安卓系统下载类 **/  
    DownloadManager manager;  

    /** 接收下载完的广播 **/  
    DownloadCompleteReceiver receiver;  

    /** 初始化下载器 **/  
    private void initDownManager() {  
        manager = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);  
        receiver = new DownloadCompleteReceiver();  

        //设置下载地址  
        DownloadManager.Request down = new DownloadManager.Request(Uri.parse("http://www.xxx.com/xx.apk"));  

        // 设置允许使用的网络类型，这里是移动网络和wifi都可以  
        down.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_MOBILE | DownloadManager.Request.NETWORK_WIFI);  

        // 下载时，通知栏显示途中  
//        down.setNotificationVisibility(Request.VISIBILITY_VISIBLE); 
        down.setNotificationVisibility(Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);  

        // 显示下载界面  
        down.setVisibleInDownloadsUi(true);  

        // 设置下载后文件存放的位置  
        down.setDestinationUri(Uri.fromFile(updateFile));

        down.setTitle("趣马养车");
        down.setDescription("下载更新");

        // 将下载请求放入队列  
        manager.enqueue(down);  

        //注册下载广播  
        registerReceiver(receiver, new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE));  
    }

    @Override  
    public int onStartCommand(Intent intent, int flags, int startId) {
        //创建文件
        if(android.os.Environment.MEDIA_MOUNTED.equals(android.os.Environment.getExternalStorageState())){
            updateDir = new File("/sdcard/download");
            fileName = "temp.apk";
            updateFile = new File(updateDir.getPath(),fileName);
        }

        // 调用下载  
        initDownManager();  

        return START_NOT_STICKY;  
    }  

    @Override  
    public IBinder onBind(Intent intent) {  
        return null;  
    }  

    @Override  
    public void onDestroy() {  
        // 注销下载广播  
        if (receiver != null)  
            unregisterReceiver(receiver);  

        super.onDestroy();  
    }  

    // 接受下载完成后的intent  
    private class DownloadCompleteReceiver extends BroadcastReceiver {  
        @Override  
        public void onReceive(Context context, Intent intent) {  
            //判断是否下载完成的广播
            if (intent.getAction().equals(DownloadManager.ACTION_DOWNLOAD_COMPLETE)) {
                DatabaseOpenHelper.writableDatabase(UpgradeService.this, new WritableHandler() {
                    @Override
                    public void exec(SQLiteDatabase db) {
                        Upgrade upgrade = DaoManager.getUpgradeDao().query(db, appid);
                        if(upgrade!=null){
                            upgrade.setStatus(UpgradeStatus.下载完成.getVal());
                            DaoManager.getUpgradeDao().update(db, upgrade);
                        }
                    }
                });

                //获取下载的文件id  
                long downId = intent.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, -1);  

                //自动安装apk
                installAPK(manager.getUriForDownloadedFile(downId));  

                //停止服务并关闭广播  
                UpgradeService.this.stopSelf();  
            }  
        }  

        /** 
         * 安装apk文件 
         */  
        private void installAPK(Uri apk) {
            // 通过Intent安装APK文件  
            Intent intents = new Intent();  

            intents.setAction("android.intent.action.VIEW");  
            intents.addCategory("android.intent.category.DEFAULT");  
            intents.setType("application/vnd.android.package-archive");
            intents.setData(apk);
            intents.setDataAndType(apk,"application/vnd.android.package-archive");  
            intents.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);  
//            android.os.Process.killProcess(android.os.Process.myPid());
            // 如果不加上这句的话在apk安装完成之后点击单开会崩溃  
            startActivity(intents);  
        }  

    }

}