android - 如何打开云端 "virtual"文件的输入流？

Question

尝试转换从 Intent.ACTION_GET_CONTENT 获取的 URI，输入流对于本地文件可以正常打开，但对于来自驱动器的 URI (/document/acc=1;doc=4089) 我收到一个 FileNotFoundException，表示该文件是“虚拟”的。如何打开此类文件的输入流？

获取 URI:

 Intent i = new Intent(Intent.ACTION_GET_CONTENT);
 i.setType("*/*"); //No I18N
 try{
    startActivityForResult(Intent.createChooser(i, "Pick a file"), REQUEST_CODE_UPLOAD_FILE_FOR_IMPORT);
    }catch (android.content.ActivityNotFoundException ex){
    Log.e("Error","FileManager not found!"); 
    }

和

importedFileUri = data.getData();
                System.out.println("URI path: "+importedFileUri.getPath()+" "+importedFileUri.getEncodedPath());
                System.out.println("URI Scheme "+importedFileUri.getScheme());
                System.out.println("URI Authority :"+importedFileUri.getAuthority());
                System.out.println("URI Fragment :"+importedFileUri.getFragment());
                System.out.println("URI path segments : ");
                for(String str : importedFileUri.getPathSegments()){
                    System.out.println("\t" +str );
                }
                String ext;
                if (importedFileUri.getScheme().equals(ContentResolver.SCHEME_CONTENT)) {
                    final MimeTypeMap mime = MimeTypeMap.getSingleton();
                    ext = mime.getExtensionFromMimeType(mActivity.getContentResolver().getType(importedFileUri));
                    System.out.println("resolved type (content) : "+ mActivity.getContentResolver().getType(importedFileUri));
                } else {
                    ext = MimeTypeMap.getFileExtensionFromUrl(Uri.fromFile(new File(importedFileUri.getPath())).toString());
                    System.out.println("resolved type (other) : "+ Uri.fromFile(new File(importedFileUri.getPath())).toString());
                }

获取输入流:

InputStream is = null;
                try {
                    is = contentResolver.openInputStream(importedFileUri);
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                }

结果:

URI path: /document/acc=1;doc=4089 /document/acc%3D1%3Bdoc%3D4089

GetString -content://com.google.android.apps.docs.storage/document/acc%3D1%3Bdoc%3D4089

URI Scheme content

URI Authority :com.google.android.apps.docs.storage

URI Fragment :null

URI path segments :

document

acc=1;doc=4089

resolved type (content) : application/vnd.google-apps.spreadsheet

ext : null

异常(exception):

java.io.FileNotFoundException: File is virtual: acc=1;doc=4089

Answer 1

检查 URI 处的文件是否为虚拟:

private static boolean isVirtualFile(Uri uri) {
   if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
       if (!DocumentsContract.isDocumentUri(activity, uri)) {
           return false;
       }

       Cursor cursor = activity.getContentResolver().query(
            uri,
            new String[]{DocumentsContract.Document.COLUMN_FLAGS},
            null, null, null);
       int flags = 0;
       if (cursor.moveToFirst()) {
           flags = cursor.getInt(0);
       }
       cursor.close();
       return (flags & DocumentsContract.Document.FLAG_VIRTUAL_DOCUMENT) != 0;
   } else {
       return false;
   }
}

使用以下命令从虚拟文件获取输入流:

private static InputStream getInputStreamForVirtualFile(Uri uri, String mimeTypeFilter)
            throws IOException {

        ContentResolver resolver = activity.getContentResolver();

        String[] openableMimeTypes = resolver.getStreamTypes(uri, mimeTypeFilter);

        if (openableMimeTypes == null ||
                openableMimeTypes.length < 1) {
            throw new FileNotFoundException();
        }

        return resolver
                .openTypedAssetFileDescriptor(uri, openableMimeTypes[0], null)
                .createInputStream();
    }

总体

if (isVirtualFile(sourceuri)) {
   input = getInputStreamForVirtualFile(sourceuri, getMimeType(name));
} else {
   input = activity.getContentResolver().openInputStream(sourceuri);
}

更多信息here .