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Android DownloadManager的超时问题

androidandroid-download-manager
3

我正在使用Android内置的DownloadManager从互联网下载文件。问题是，一旦我将下载加入队列，它就会永远尝试下载该文件！是否有任何方法为下载设置超时时间？

2个回答
3

@Sofien Rahmouni和@flegare的解决方案是好的想法，但我会尝试给出一个完整可行的示例。我花了几个小时来解决这个问题，所以它可以节省某人的“搜索”时间。主要思路是如果小型和大型文件下载失败或超时，则重试下载过程-在6-7MB上进行测试。首先删除该ID的下载，并重新调用下载方法。对于STATUS_RUNNING，我递归地调用 manageDownloadProcess（urlLink，pathUri，fileName，downloadId）; 方法，以确保下载成功完成。

唯一的问题是我在第一次检查时总是得到 STATUS_PENDING ，即使它必须是STATUS_RUNNING，我实现了一个解决方案来避免这种情况。

import android.app.DownloadManager;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.database.Cursor;
import android.net.Uri;
import android.os.Handler;
import android.util.Log;

/**
 * Created by Android Developer on 29.10.2015. Copyright ©
 */
public class DownloadFile {

    private static Context mContext = App.getUniversalContext();//here just get aplication context - I have a static method in App class
    private static DownloadManager downloadManager = (DownloadManager) App.getUniversalContext().getSystemService(Context.DOWNLOAD_SERVICE);
    private static int RETRIES_MAX_NUMBER = 3; //nr of retries
    private static int alreadyRetried;
    private static boolean isEntered = false; 

    public static void downloadFile(String urlLink, String pathUri, String fileName) {
        DownloadManager.Request request = new DownloadManager.Request(Uri.parse(urlLink));
        request.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_MOBILE | DownloadManager.Request.NETWORK_WIFI);
        request.setDestinationInExternalPublicDir(pathUri, fileName);
        request.setDescription("System download");
        request.setTitle("ADMINISTRATOR");
        request.setVisibleInDownloadsUi(false);
        request.setNotificationVisibility(2)

        final long downloadId = downloadManager.enqueue(request);
        manageDownloadProcess(urlLink, pathUri, fileName, downloadId);

        App.getUniversalContext().registerReceiver(new BroadcastReceiver() {
            public void onReceive(Context ctxt, Intent intent) {
                if (downloadId == intent.getExtras().getLong(DownloadManager.EXTRA_DOWNLOAD_ID)) {
                    mContext.unregisterReceiver(this);
                    //done use your file
                }
            }
        }, new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE));
    }

    /*check for timeout / errors and retry logic*/
    private static void manageDownloadProcess(final String urlLink, final String pathUri, final String fileName, final long downloadId) {
        DownloadManager.Query query = new DownloadManager.Query();
        query.setFilterByStatus(DownloadManager.STATUS_PENDING | DownloadManager.STATUS_SUCCESSFUL | DownloadManager.STATUS_PAUSED | DownloadManager.STATUS_RUNNING | DownloadManager.STATUS_FAILED);

        final Cursor cursor = downloadManager.query(query.setFilterById(downloadId));
        final Handler handler = new Handler();
        handler.postDelayed(new Runnable() {
            @Override
            public void run() {
                if (cursor.moveToFirst()) {
                    int status = cursor.getInt(cursor.getColumnIndex(DownloadManager.COLUMN_STATUS));
                    switch (status) {

                        /*I introdused 'isEntered' param to eliminate first response from this method
                          * I don't know why but I get STATUS_PENDING always on first run, so this is an ugly workaround*/
                        case DownloadManager.STATUS_PENDING: {
                         Log.d("status", "STATUS_PENDING - timeout");
                            if (isEntered) {
                                if (alreadyRetried < RETRIES_MAX_NUMBER) {
                                    alreadyRetried++;
                                    downloadManager.remove(downloadId);
                                    downloadFile(urlLink, pathUri, fileName);
                                    manageDownloadProcess(urlLink, pathUri, fileName, downloadId);

                                }
                            } else {
                                isEntered = true;
                                manageDownloadProcess(urlLink, pathUri, fileName, downloadId);
                            }
                            break;
                        }

                        case DownloadManager.STATUS_PAUSED: {
                            Log.d("status", "STATUS_PAUSED - error");
                            if (alreadyRetried < RETRIES_MAX_NUMBER) {
                                alreadyRetried++;
                                downloadManager.remove(downloadId);
                                downloadFile(urlLink, pathUri, fileName);
                            }
                            break;
                        }

                        case DownloadManager.STATUS_RUNNING: {
                            Log.d("status", "STATUS_RUNNING - good");
                            manageDownloadProcess(urlLink, pathUri, fileName, downloadId);
                            break;
                        }

                        case DownloadManager.STATUS_SUCCESSFUL: {
                            Log.d("status", "STATUS_SUCCESSFUL - done");
                            break;
                        }

                        case DownloadManager.STATUS_FAILED: {
                            Log.d("status", "STATUS_FAILED - error");
                            if (alreadyRetried < RETRIES_MAX_NUMBER) {
                                alreadyRetried++;
                                downloadManager.remove(downloadId);
                                downloadFile(urlLink, pathUri, fileName);
                            }
                            break;
                        }
                    }
                }
            }
        }, 5000);//do this after 5 sec
    }

}
对我来说，有时即使是无效的网址，下载状态仍处于RUNNING状态...我通过改变检查多长时间没有下载任何字节的逻辑来解决了这个问题。 - Gilian
1

不幸的是，Android并没有提供在DownloadManager中设置超时时间的解决方案。但实际上，当您处于挂起状态：DownloadManager.STATUS_PENDING时，您可以设置一个TIMEOUT ClockWake。

DownloadManager.Query query = null;
    Cursor c = null;
    DownloadManager downloadManager = null;
    downloadManager = (DownloadManager)getSystemService(Context.DOWNLOAD_SERVICE);
    query = new DownloadManager.Query();
     if(query!=null) {
                query.setFilterByStatus(DownloadManager.STATUS_FAILED|DownloadManager.STATUS_PAUSED|DownloadManager.STATUS_SUCCESSFUL|
                        DownloadManager.STATUS_RUNNING|DownloadManager.STATUS_PENDING);
            } else {
                return;
            }
    c = downloadManager.query(query);
    if(c.moveToFirst()) { 
    int status = c.getInt(c.getColumnIndex(DownloadManager.COLUMN_STATUS)); 
    switch(status) { 
    case DownloadManager.STATUS_PAUSED: 
    break; 
    case DownloadManager.STATUS_PENDING: 
    //here you can set your TIMEOUT solution
    break; 
    case DownloadManager.STATUS_RUNNING: 
    break; 
    case DownloadManager.STATUS_SUCCESSFUL: 
    break; 
    case DownloadManager.STATUS_FAILED: 
    break; 
    }
似乎下载管理器仅适用于正常情况。没有处理超时等许多问题的情况。因此，最好使用Retrofit创建自定义下载文件逻辑并处理所有情况。 - Kostadin Georgiev
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