我想从驱动器下载文本和pdf文件并将其保存在设备中。 我尝试了大量的链接，但无法找到正确的解决方案。 我试过的代码如下所示
我尝试使用以下代码下载google驱动器文件。
Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
intent.addCategory(Intent.CATEGORY_OPENABLE);
intent.setType("application/*");
Intent i = Intent.createChooser(intent, "Choose an application");
startActivityForResult(i, RC_FILE);
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK) {
if (requestCode == RC_PICK_A_FILE) {
Uri inputStreamUri = data.getData();
String filePath = FilePickUtils.getPath(
getApplicationContext(), inputStreamUri);
}
}
}
和FilePickutils
public class FilePickUtils {
@SuppressLint("NewApi")
public static String getPath(final Context context, final Uri uri) {
// check here to KITKAT or new version
final boolean isKitKatorUp = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
// DocumentProvider
if (isKitKatorUp && DocumentsContract.isDocumentUri(context, uri)) {
// ExternalStorageProvider
if (isExternalStorageDocument(uri)) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
if ("primary".equalsIgnoreCase(type)) {
return Environment.getExternalStorageDirectory() + "/"
+ split[1];
}
}
// DownloadsProvider
else if (isDownloadsDocument(uri)) {
final String id = DocumentsContract.getDocumentId(uri);
final Uri contentUri = ContentUris.withAppendedId(
Uri.parse("content://downloads/public_downloads"),
Long.valueOf(id));
return getDataColumn(context, contentUri, null, null);
}
// MediaProvider
else if (isMediaDocument(uri)) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
Uri contentUri = null;
if ("image".equals(type)) {
contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
} else if ("video".equals(type)) {
contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
} else if ("audio".equals(type)) {
contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
}
final String selection = "_id=?";
final String[] selectionArgs = new String[] { split[1] };
return getDataColumn(context, contentUri, selection,
selectionArgs);
}else if(isGoogleFileUri(uri))
{
Log.d("tag","====isGoogleFileUri========="+uri);
return getDataColumn(context, uri, null, null);
}
}
// MediaStore (and general)
else if ("content".equalsIgnoreCase(uri.getScheme())) {
// Return the remote address
if (isGooglePhotosUri(uri))
return uri.getLastPathSegment();
return getDataColumn(context, uri, null, null);
}
// File
else if ("file".equalsIgnoreCase(uri.getScheme())) {
return uri.getPath();
}
return null;
}
/**
* Get the value of the data column for this Uri. This is useful for
* MediaStore Uris, and other file-based ContentProviders.
*
* @param context
* The context.
* @param uri
* The Uri to query.
* @param selection
* (Optional) Filter used in the query.
* @param selectionArgs
* (Optional) Selection arguments used in the query.
* @return The value of the _data column, which is typically a file path.
*/
public static String getDataColumn(Context context, Uri uri,
String selection, String[] selectionArgs) {
Cursor cursor = null;
final String column = "_data";
final String[] projection = { column };
try {
cursor = context.getContentResolver().query(uri,new String[] { android.provider.MediaStore.Files.FileColumns.DATA },
null, null, null);
Log.d("tag","=====cursor===="+cursor);
/* Cursor cursor = this.getContentResolver().query(_uri, new String[] { android.provider.MediaStore.Images.ImageColumns.DATA }, null, null, null);
cursor.moveToFirst();
filePath = cursor.getString(0);
cursor.close();*/
if (cursor != null && cursor.moveToFirst()) {
int idx = cursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns.DATA);
// final int index = cursor.getColumnIndexOrThrow(column);
Log.d("tag","========index==="+idx);
Log.d("tag","======cursor.getString(index)====="+cursor.getString(idx));
return cursor.getString(idx);
}
} finally {
if (cursor != null)
cursor.close();
}
return null;
}
/**
* @param uri
* The Uri to check.
* @return Whether the Uri authority is ExternalStorageProvider.
*/
public static boolean isExternalStorageDocument(Uri uri) {
return "com.android.externalstorage.documents".equals(uri
.getAuthority());
}
/**
* @param uri
* The Uri to check.
* @return Whether the Uri authority is DownloadsProvider.
*/
public static boolean isDownloadsDocument(Uri uri) {
return "com.android.providers.downloads.documents".equals(uri
.getAuthority());
}
/**
* @param uri
* The Uri to check.
* @return Whether the Uri authority is MediaProvider.
*/
public static boolean isMediaDocument(Uri uri) {
return "com.android.providers.media.documents".equals(uri
.getAuthority());
}
/**
* @param uri
* The Uri to check.
* @return Whether the Uri authority is Google Photos.
*/
public static boolean isGooglePhotosUri(Uri uri) {
return "com.google.android.apps.photos.content".equals(uri
.getAuthority());
}
public static boolean isGoogleFileUri(Uri uri) {
return "com.google.android.apps.docs.storage".equals(uri
.getAuthority());
}
}
我最终未能获得以下内容uri
content://com.google.android.apps.docs.storage/document/acc%3D19%3Bdoc%3D10211
filePath返回为“null”
答案 0 :(得分：2)
给定Uri，要制作本地文件副本，您：
使用ContentResolver和openInputStream()获取InputStream
Uri
在所需文件
FileOutputStream
使用标准Java I / O将字节从InputStream复制到FileOutputStream
你最终得到这样的代码：
FileOutputStream fos=new FileOutputStream(f);
BufferedOutputStream out=new BufferedOutputStream(fos);
InputStream in=
getContentResolver().openInputStream(document);
try {
byte[] buffer=new byte[8192];
int len=0;
while ((len=in.read(buffer))>=0) {
out.write(buffer, 0, len);
}
out.flush();
}
finally {
fos.getFD().sync();
out.close();
in.close();
}
（其中document是Uri而f是目的地File）
答案 1 :(得分：0)
Uri uri = data.getData();
直接使用uri打开一个InputStream来读取它。废除那些filepicker工具。你不需要文件路径。
InputStream is = getContentResolver().openInputStream(uri);
这就是全部。
答案 2 :(得分：-1)
解决方案：
@Override
@SuppressLint("NewApi")
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == CropImage.PICK_IMAGE_CHOOSER_REQUEST_CODE) {
if (resultCode == Activity.RESULT_OK) {
Uri mUri = CropImage.getPickImageResultUri(this, data);
writeStreamToFile(getApplicationContext(),mUri,".pdf");
}
}
}
方法：
@RequiresApi(api = Build.VERSION_CODES.KITKAT)
void writeStreamToFile(Context mContext, Uri mUri,String ext) {
if (mUri == null) {
return;
}
String[] filePathColumn = {MediaStore.Images.Media.DATA};
Cursor cursor = mContext.getContentResolver().query(mUri, filePathColumn, null, null, null);
String mCurrentPath = null;
if (cursor != null && cursor.moveToFirst()) {
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
mCurrentPath = cursor.getString(columnIndex);
cursor.close();
}
if (TextUtils.isEmpty(mCurrentPath)) {
mCurrentPath = mUri.getPath();
}
File storageDir = mContext.getExternalFilesDir(Environment.DIRECTORY_DOCUMENTS);
InputStream inputStream = null;
try {
inputStream = mContext.getContentResolver().openInputStream(mUri);
File file = File.createTempFile("pptFiles", ext, storageDir);
try (OutputStream output = new FileOutputStream(file)) {
byte[] buffer = new byte[4 * 1024]; // or other buffer size
int read;
while ((read = inputStream.read(buffer)) != -1) {
output.write(buffer, 0, read);
}
output.flush();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
inputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}