Question

有一些类似的问题已被问到，但我的有点不同，我有以下代码在我的应用程序上下载：

 DownloadManager.Request request = new DownloadManager.Request(uri)
                        .setTitle(fileInfo.getFileName())
                        .setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS,
                                getString(R.string.app_name) + File.separator + fileInfo.getFileName());

                    if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
                        request.allowScanningByMediaScanner();
                    }
 manager.enqueue(request);

这样可以正常工作而不会抱怨至少三星S4，Nexus 4，Nexus 7，但是我最近发现在某些设备上它无法创建带错误的目录：

所以现在我正在检查目录并创建它是否与

不存在

File downloadDir = new File (Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS)
                            + File.separator + getString(R.string.app_name));

                    if (!downloadDir.exists()){
                        boolean mkdir = downloadDir.mkdir();
                    }

我的问题是，为什么DownloadManager行为不同，这是Android版本或供应商问题以及预期的行为是什么，因为getExternalStoragePublicDirectory的文档声明它可能会抛出IllegalStateException: IllegalStateException If the external storage directory cannot be found or created.

我认为它应该尝试创建目录，在这种情况下应该没有理由或者我需要使用mkdir函数，但事实并非如此

Answer 1

I had the same behavior on LG G3 without subdirectory creation:

W/DownloadManager: Aborting request for download 544: Failed to create target file /storage/emulated/0/Download/Sub Directory/IMG_20150422_160932.jpg
               com.android.providers.downloads.StopRequestException: Failed to create target file /storage/emulated/0/Download/Sub Directory/IMG_20150422_160932.jpg
                   at com.android.providers.downloads.Helpers.getFullPath(Helpers.java:213)
                   at com.android.providers.downloads.Helpers.generateSaveFile(Helpers.java:166)
                   at com.android.providers.downloads.DownloadThread.processResponseHeaders(DownloadThread.java:2054)
                   at com.android.providers.downloads.DownloadThread.access$500(DownloadThread.java:130)
                   at com.android.providers.downloads.DownloadThread$ContentAnalyzer.init(DownloadThread.java:274)
                   at com.android.providers.downloads.DownloadThread.executeDownload(DownloadThread.java:922)
                   at com.android.providers.downloads.DownloadThread.runInternal(DownloadThread.java:784)

calling this method before helps:

        private void createDirectoryIfNecessary() {
            File downloadDir = new File (Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS)
                    + File.separator + subdirectory);
            if (!downloadDir.exists()){
                downloadDir.mkdirs();
            }
        }

创建目录时的DownloadManager行为

1 个答案: