来自树 URI 的 Android 5.0 DocumentFile [英] Android 5.0 DocumentFile from tree URI
问题描述
好吧，我找了又找，没有人有我的确切答案，或者我错过了.我让我的用户通过以下方式选择目录:
Alright, I've searched and searched and no one has my exact answer, or I missed it. I'm having my users select a directory by:
Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT_TREE);
startActivityForResult(intent, READ_REQUEST_CODE);
在我的活动中，我想捕捉实际路径，这似乎是不可能的.
In my activity I want to capture the actual path, which seems to be impossible.
protected void onActivityResult(int requestCode, int resultCode, Intent intent){
super.onActivityResult(requestCode, resultCode, intent);
if (resultCode == RESULT_OK) {
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.M){
//Marshmallow
} else if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP){
//Set directory as default in preferences
Uri treeUri = intent.getData();
//grant write permissions
getContentResolver().takePersistableUriPermission(treeUri, Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
//File myFile = new File(uri.getPath());
DocumentFile pickedDir = DocumentFile.fromTreeUri(this, treeUri);
我选择的文件夹位于:
Device storage/test/
我已经尝试了以下所有方法来获取确切的路径名，但都无济于事.
I've tried all of the following ways to get an exact path name, but to no avail.
File myFile = new File (uri.getPath());
//returns: /tree/1AF6-3708:test
treeUri.getPath();
//returns: /tree/1AF6-3708:test/
pickedDir.getName()
//returns: test
pickedDir.getParentFile()
//returns: null
基本上我需要将 /tree/1AF6-3708: 转换为 /storage/emulated/0/ 或每个设备调用它的存储位置.所有其他可用选项也返回 /tree/1AF6-37u08:.
Basically I need to turn /tree/1AF6-3708: into /storage/emulated/0/ or whatever each device calls it's storage location. All other available options return /tree/1AF6-37u08: also.
我想这样做有两个原因.
There are 2 reasons I want to do it this way.
1) 在我的应用程序中，我将文件位置存储为共享首选项，因为它是特定于用户的.我有相当多的数据将被下载和存储，我希望用户能够把它放在他们想要的地方，特别是如果他们有一个额外的存储位置.我确实设置了默认值，但我想要多功能性，而不是以下专用位置:
1) In my app I store the file location as a shared preference because it is user specific. I have quite a bit of data that will be downloaded and stored and I want the user to be able to place it where they want, especially if they have an additional storage location. I do set a default, but I want versatility, rather than the dedicated location of:
Device storage/Android/data/com.app.name/
2) 在 5.0 中，我想让用户获得对该文件夹的读/写权限，这似乎是唯一的方法.如果我可以从可以解决此问题的字符串中获得读/写权限.
2) In 5.0 I want to enable the user to get read/write permissions to that folder and this seems the only way to do that. If I can get read/write permissions from a string that would fix this issue.
我能找到的所有解决方案都与 Mediastore 相关，这对我没有帮助.我一定是在某处遗漏了一些东西，否则我一定对它上瘾了.任何帮助，将不胜感激.谢谢.
All solutions I've been able to find relate to Mediastore, which doesn't help me exactly. I have to be missing something somewhere or I must have glazed over it. Any help would be appreciated. Thanks.
推荐答案
这将为您提供所选文件夹的实际路径 它仅适用于属于本地存储的文件/文件夹.
This will give you the actual path of the selected folder It will work ONLY for files/folders that belong in local storage.
Uri treeUri = data.getData();
String path = FileUtil.getFullPathFromTreeUri(treeUri,this);
其中 FileUtil 是以下类
where FileUtil is the following class
public final class FileUtil {
private static final String PRIMARY_VOLUME_NAME = "primary";
@Nullable
public static String getFullPathFromTreeUri(@Nullable final Uri treeUri, Context con) {
if (treeUri == null) return null;
String volumePath = getVolumePath(getVolumeIdFromTreeUri(treeUri),con);
if (volumePath == null) return File.separator;
if (volumePath.endsWith(File.separator))
volumePath = volumePath.substring(0, volumePath.length() - 1);
String documentPath = getDocumentPathFromTreeUri(treeUri);
if (documentPath.endsWith(File.separator))
documentPath = documentPath.substring(0, documentPath.length() - 1);
if (documentPath.length() > 0) {
if (documentPath.startsWith(File.separator))
return volumePath + documentPath;
else
return volumePath + File.separator + documentPath;
}
else return volumePath;
}
private static String getVolumePath(final String volumeId, Context context) {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP)
return null;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R)
return getVolumePathForAndroid11AndAbove(volumeId, context);
else
return getVolumePathBeforeAndroid11(volumeId, context);
}
private static String getVolumePathBeforeAndroid11(final String volumeId, Context context){
try {
StorageManager mStorageManager = (StorageManager) context.getSystemService(Context.STORAGE_SERVICE);
Class<?> storageVolumeClazz = Class.forName("android.os.storage.StorageVolume");
Method getVolumeList = mStorageManager.getClass().getMethod("getVolumeList");
Method getUuid = storageVolumeClazz.getMethod("getUuid");
Method getPath = storageVolumeClazz.getMethod("getPath");
Method isPrimary = storageVolumeClazz.getMethod("isPrimary");
Object result = getVolumeList.invoke(mStorageManager);
final int length = Array.getLength(result);
for (int i = 0; i < length; i++) {
Object storageVolumeElement = Array.get(result, i);
String uuid = (String) getUuid.invoke(storageVolumeElement);
Boolean primary = (Boolean) isPrimary.invoke(storageVolumeElement);
if (primary && PRIMARY_VOLUME_NAME.equals(volumeId)) // primary volume?
return (String) getPath.invoke(storageVolumeElement);
if (uuid != null && uuid.equals(volumeId)) // other volumes?
return (String) getPath.invoke(storageVolumeElement);
}
// not found.
return null;
} catch (Exception ex) {
return null;
}
}
@TargetApi(Build.VERSION_CODES.R)
private static String getVolumePathForAndroid11AndAbove(final String volumeId, Context context) {
try {
StorageManager mStorageManager = (StorageManager) context.getSystemService(Context.STORAGE_SERVICE);
List<StorageVolume> storageVolumes = mStorageManager.getStorageVolumes();
for (StorageVolume storageVolume : storageVolumes) {
// primary volume?
if (storageVolume.isPrimary() && PRIMARY_VOLUME_NAME.equals(volumeId))
return storageVolume.getDirectory().getPath();
// other volumes?
String uuid = storageVolume.getUuid();
if (uuid != null && uuid.equals(volumeId))
return storageVolume.getDirectory().getPath();
}
// not found.
return null;
} catch (Exception ex) {
return null;
}
}
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
private static String getVolumeIdFromTreeUri(final Uri treeUri) {
final String docId = DocumentsContract.getTreeDocumentId(treeUri);
final String[] split = docId.split(":");
if (split.length > 0) return split[0];
else return null;
}
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
private static String getDocumentPathFromTreeUri(final Uri treeUri) {
final String docId = DocumentsContract.getTreeDocumentId(treeUri);
final String[] split = docId.split(":");
if ((split.length >= 2) && (split[1] != null)) return split[1];
else return File.separator;
}
}
更新:
解决评论中提到的下载问题:如果您从默认 Android 文件选择器的左侧抽屉中选择 Downloads，您实际上并未选择目录.下载是一个提供者.一个普通的文件夹树 uri 看起来像这样:
To address the Downloads issue mentioned in the comments: If you select Downloads from the left drawer in the default Android file picker you are not actually selecting a directory. Downloads is a provider. A normal folder tree uri looks something like this:
content://com.android.externalstorage.documents/tree/primary%3ADCIM
下载的树uri是
content://com.android.providers.downloads.documents/tree/downloads
你可以看到一个写着externalstorage，而另一个写着providers.这就是为什么它不能与文件系统中的目录匹配的原因.因为它不是目录.
You can see that the one says externalstorage while the other one says providers. That is why it cannot be matched to a directory in the file system. Because it is not a directory.
解决方案:您可以添加相等性检查，如果树 uri 等于该值，则返回可以像这样检索的默认下载文件夹路径:
SOLUTION: You can add an equality check and if the tree uri is equal to that then return the default download folder path which can be retrieved like this:
Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);
如果您愿意，还可以为所有提供者执行类似的操作.我假设它会在大部分时间正常工作.但我想在某些边缘情况下它不会.
And do something similar for all the providers if you wish to. And it would work correctly most of the time I assume. But I imagine that there are edge cases where it wouldn't.
感谢@DuhVir 支持 Android R 案例
thanx to @DuhVir for supporting the Android R case
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