SAF - 文件写入父文件夹，而不是正确的路径

Question

我的应用程序想要将文件从私有应用程序文件夹复制到在用户选择的 SAF 文件夹中创建的 SAF 文件夹。 文件夹创建没问题。

复制方法是：

public static boolean copyFileToTargetSAFFolder(Context context, String filePath, String targetFolder, String destFileName ) 
{


    Uri uri = Uri.parse(targetFolder);

    String docId = DocumentsContract.getTreeDocumentId(uri);
    Log.d("target folder uri",uri.toString());
    Log.d("target folder id",docId);
    Uri dirUri = DocumentsContract.buildDocumentUriUsingTree(uri, docId );
    Log.d("dir uri",dirUri.toString());
    Uri destUri = null;

    try
    {
        destUri = DocumentsContract.createDocument(context.getContentResolver(), dirUri, "*/*", destFileName);
        Log.d("dest uri",destUri.toString());
    } catch (FileNotFoundException e )
    {
        e.printStackTrace();

        return false;
    }

    InputStream is = null;
    OutputStream os = null;
    try {
        is = new FileInputStream(filePath);

        os = context.getContentResolver().openOutputStream( destUri, "w");

        byte[] buffer = new byte[1024];

        int length;
        while ((length = is.read(buffer)) > 0)
            os.write(buffer, 0, length);

        is.close();
        os.flush();
        os.close();

        return true;

    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e)     {
        e.printStackTrace();
    }

    return false;
}

日志是：

target folder uri: content://com.android.providers.downloads.documents/tree/raw%3A%2Fstorage%2Femulated%2F0%2FDownload%2Ffoldername/document/raw%3A%2Fstorage%2Femulated%2F0%2FDownload%2Ffoldername%2Fsubfoldername

target folder id: raw:/storage/emulated/0/Download/foldername

dir uri: content://com.android.providers.downloads.documents/tree/raw%3A%2Fstorage%2Femulated%2F0%2FDownload%2Ffoldername/document/raw%3A%2Fstorage%2Femulated%2F0%2FDownload%2Ffoldername

dest uri: content://com.android.providers.downloads.documents/tree/raw%3A%2Fstorage%2Femulated%2F0%2FDownload%2Ffoldername/document/raw%3A%2Fstorage%2Femulated%2F0%2FDownload%2Ffoldername%2Ffile.txt

这确实是文件系统上发生的事情。 实际上，文件是在父文件夹中复制和创建的，而不是在子文件夹中。 此代码来自关于 SO 的答案：

SAF - DocumentsContract.createDocument 方法中的无效 URI 错误（FileOutputStream 副本）

Answer 1

我不知道这是否只是一种解决方法，但如果我更换

String docId = DocumentsContract.getTreeDocumentId(uri);

和

String docId = DocumentsContract.getDocumentId(uri);

该方法有效。

public static boolean copyFileToTargetSAFFolder(Context context, String filePath, String targetFolder, String destFileName ) 
{


    Uri uri = Uri.parse(targetFolder);

    String docId = DocumentsContract.getDocumentId(uri);
    Uri dirUri = DocumentsContract.buildDocumentUriUsingTree(uri, docId );
    Uri destUri = null;

    try
    {
       destUri = DocumentsContract.createDocument(context.getContentResolver(), dirUri, "*/*", destFileName);

    } catch (FileNotFoundException e )
    {
        e.printStackTrace();

        return false;
    }

    InputStream is = null;
    OutputStream os = null;
    try {
        is = new FileInputStream(filePath);

        os = context.getContentResolver().openOutputStream( destUri, "w");

        byte[] buffer = new byte[1024];

        int length;
        while ((length = is.read(buffer)) > 0)
            os.write(buffer, 0, length);

        is.close();
        os.flush();
        os.close();

        return true;

    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e)     {
        e.printStackTrace();
    }

    return false;
}

确实现在日志有

dirUri content://com.android.providers.downloads.documents/tree/raw%3A%2Fstorage%2Femulated%2F0%2FDownload%2Ffoldername/document/raw%3A%2Fstorage%2Femulated%2F0%2FDownload%2Ffoldername%2Fsubfoldername

该文件已正确复制到此文件夹中。