问题
I am trying to upload multiple images from gallery at once. given here. The issue i am facing is converting the string to bitmap. I got the following error.
E/BitmapFactory: Unable to decode stream: java.io.FileNotFoundException: /storage/emulated/0/DCIM/Screenshots/Screenshot_2018-11-05-14-59-33-023_com.android.mms.png (Permission denied)
The error occurs here.
Bitmap bitmap2 = PhotoLoader.init().from(imagePath).requestSize(512, 512).getBitmap();
final String encodedString = ImageBase64.encode(bitmap2); // getting the exception
but in my Log.e there is value in imagepath but cant get value in bitmap2.
ButtonCode to upload images to server is below.
buttonmultiUpload.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(getApplicationContext(), "Upload button is clicked" + imagesEncodedList, Toast.LENGTH_LONG).show();
Log.e("list","imagesEncodedList" + imagesEncodedList );
for( String imagePath: imagesEncodedList){
try {
Log.e("imagePath","imagePath" + imagePath );
Bitmap bitmap2 = PhotoLoader.init().from(imagePath).requestSize(512, 512).getBitmap();
final String encodedString = ImageBase64.encode(bitmap2);
Log.e("bitmap","bitmap" + bitmap2 );
String url = "http://myserver.com/imageuploadtest/upload.php";
StringRequest stringRequest = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
Toast.makeText(getApplicationContext(), response, Toast.LENGTH_SHORT).show();
// gvGallery.setAdapter(null);
new AlertDialog.Builder(MainActivity.this).setTitle("Succesful")
.setMessage("Multiple Prescription of Outdoor has been submitted")
.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
}
}).show();
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(getApplicationContext(), "Error while uploading image", Toast.LENGTH_SHORT).show();
}
}){
@Override
protected Map<String, String> getParams() throws AuthFailureError {
Map<String, String> params = new HashMap<>();
params.put("image", encodedString);
params.put("empcode", emp_code);
return params;
}
};
myCommand.add(stringRequest);
} catch (FileNotFoundException e) {
Toast.makeText(getApplicationContext(), "Error while loading image", Toast.LENGTH_SHORT).show();
}
}
myCommand.execute();
}
});
code of Activity result
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
{
Toast.makeText(getApplicationContext(), "Clicked for multiple image", Toast.LENGTH_LONG).show();
String[] filePathColumn = { MediaStore.Images.Media.DATA };
imagesEncodedList = new ArrayList<String>();
if(data.getData()!=null){
Uri mImageUri=data.getData();
try {
bitmap=BitmapFactory.decodeStream(getContentResolver().openInputStream(mImageUri));
bitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), mImageUri);
} catch (IOException e) {
e.printStackTrace();
}
setToImageView(getResizedBitmap(bitmap, 2048));
Cursor cursor = getContentResolver().query(mImageUri, filePathColumn, null, null, null);
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
imageEncoded = cursor.getString(columnIndex);
cursor.close();
ArrayList<Uri> mArrayUri = new ArrayList<Uri>();
mArrayUri.add(mImageUri);
galleryAdapter = new GalleryAdapter(getApplicationContext(),mArrayUri);
gvGallery.setAdapter(galleryAdapter);
gvGallery.setVerticalSpacing(gvGallery.getHorizontalSpacing());
ViewGroup.MarginLayoutParams mlp = (ViewGroup.MarginLayoutParams) gvGallery.getLayoutParams();
mlp.setMargins(0, gvGallery.getHorizontalSpacing(), 0, 0);
} else {
if (data.getClipData() != null) {
ClipData mClipData = data.getClipData();
ArrayList<Uri> mArrayUri = new ArrayList<Uri>();
for (int i = 0; i < mClipData.getItemCount(); i++) {
ClipData.Item item = mClipData.getItemAt(i);
Uri uri = item.getUri();
mArrayUri.add(uri);
Cursor cursor = getContentResolver().query(uri, filePathColumn, null, null, null);
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
imageEncoded = cursor.getString(columnIndex);
imagesEncodedList.add(imageEncoded);
cursor.close();
galleryAdapter = new GalleryAdapter(getApplicationContext(),mArrayUri);
gvGallery.setAdapter(galleryAdapter);
gvGallery.setVerticalSpacing(gvGallery.getHorizontalSpacing());
ViewGroup.MarginLayoutParams mlp = (ViewGroup.MarginLayoutParams) gvGallery.getLayoutParams();
mlp.setMargins(0, gvGallery.getHorizontalSpacing(), 0, 0);
}
Log.v("LOG_TAG", "Selectedmages " + mArrayUri.size());
Log.v("LOG_TAG", "Selectedmages " + imagesEncodedList );
Log.v("LOG_TAG", "Selectedmages " + bitmap );
}
}
}
回答1:
Add these two to Mainfest.xml file
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
Then you need to request permission before any operation dynamically like below
if (ContextCompat.checkSelfPermission(thisActivity,Manifest.permission.WRITE_EXTERNAL_STORAGE)!= PackageManager.PERMISSION_GRANTED) {
// Permission is not granted
if (ActivityCompat.shouldShowRequestPermissionRationale(thisActivity,
Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
// Show an explanation to the user *asynchronously* -- don't block
// this thread waiting for the user's response! After the user
// sees the explanation, try again to request the permission.
} else {
// No explanation needed; request the permission
ActivityCompat.requestPermissions(thisActivity,
new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
MY_PERMISSIONS_WRITE_EXTERNAL_STORAGE);
}
}
回答2:
After android 6.0, only declare permissions request in AndroidManifest.Xml is not enough, you also explicitly request corresponding permissions before doing some task.
ActivityCompat.requestPermissions(MainActivity.this,
new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
1);
and
@Override
public void onRequestPermissionsResult(int requestCode,
String permissions[], int[] grantResults) {
switch (requestCode) {
case 1:
{
if (grantResults.length > 0 &&
grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// permission was granted, do something you want
} else {
// permission denied
Toast.makeText(MainActivity.this, "Permission denied to read your External storage", Toast.LENGTH_SHORT).show();
}
return;
}
}
}
来源：https://stackoverflow.com/questions/53358582/unable-to-decode-stream-java-io-filenotfoundexception-permission-denied