安卓DownloadManager封装，系统下载器的简单使用

直接上代码：

public class DownloadUtils {
    //下载器
    private DownloadManager downloadManager;
    //上下文
    private Context mContext;
    //下载的ID
    private long downloadId;
    //下载提示标题
    private String title;
    //下载描述
    private String desc;
    public  DownloadUtils(Context context,String title,String desc){
        this.mContext = context;
        this.title = title;
        this.desc = desc;
    }

    //下载apk
    public void downloadAPK(String url, String name) {

        //创建下载任务
        DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
        //移动网络情况下是否允许漫游
        request.setAllowedOverRoaming(false);

        //在通知栏中显示，默认就是显示的
        request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE);
        request.setTitle(title);
        request.setDescription(desc);
        request.setVisibleInDownloadsUi(true);

        //设置下载的路径
        request.setDestinationInExternalPublicDir(Environment.getExternalStorageDirectory().getAbsolutePath() , name);

        //获取DownloadManager
        downloadManager = (DownloadManager) mContext.getSystemService(Context.DOWNLOAD_SERVICE);
        //将下载请求加入下载队列，加入下载队列后会给该任务返回一个long型的id，通过该id可以取消任务，重启任务、获取下载的文件等等
        downloadId = downloadManager.enqueue(request);

        //注册广播接收者，监听下载状态
        mContext.registerReceiver(receiver,
                new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE));
    }

    //广播监听下载的各个状态
    private BroadcastReceiver receiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            checkStatus();
        }
    };


    //检查下载状态
    private void checkStatus() {
        DownloadManager.Query query = new DownloadManager.Query();
        //通过下载的id查找
        query.setFilterById(downloadId);
        Cursor c = downloadManager.query(query);
        if (c.moveToFirst()) {
            int status = c.getInt(c.getColumnIndex(DownloadManager.COLUMN_STATUS));
            switch (status) {
                //下载暂停
                case DownloadManager.STATUS_PAUSED:
                    break;
                //下载延迟
                case DownloadManager.STATUS_PENDING:
                    break;
                //正在下载
                case DownloadManager.STATUS_RUNNING:
                    break;
                //下载完成
                case DownloadManager.STATUS_SUCCESSFUL:
                    //下载完成安装APK
                    installAPK();
                    break;
                //下载失败
                case DownloadManager.STATUS_FAILED:
                    Toast.makeText(mContext, "下载失败", Toast.LENGTH_SHORT).show();
                    break;
            }
        }
        c.close();
    }

    //下载到本地后执行安装
    private void installAPK() {
        //获取下载文件的Uri
        Uri downloadFileUri = downloadManager.getUriForDownloadedFile(downloadId);
        if (downloadFileUri != null) {
            Intent intent= new Intent(Intent.ACTION_VIEW);
            intent.setDataAndType(downloadFileUri, "application/vnd.android.package-archive");
            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            mContext.startActivity(intent);
            mContext.unregisterReceiver(receiver);
        }
    }

}

使用方法：

 DownloadUtils downloadUtils = new DownloadUtils(MainActivity.this,"新版本XXX","正在下载")
 downloadUtils.downloadAPK("http://192.168.1.135:8080/aaa.apk", "aaa.apk");