Develop Reference

Importing images into DataBase

in my app I use SqLite Database "Templates", where I have table "favourites", constains of four columns "id", "description", "imagePath", "category". I would like user to be able use their own images in my app, like this:
When user click button, he choose image from gallery, write description and choose category of image. I know I need use Content Values to do this. But how can I do my table has imagePathes, i.e how can I show them later using RecyclerView and Picasso?

You can load image from device memory:
Picasso.get().load(new File("path-to-you-image/image.png")).into(imageView);
If you are asking "how to get image path" - you can get it in the onActivityResult method:
Uri selectedImage = data.getData();
String[] filePathColumn = { MediaStore.Images.Media.DATA };
Cursor cursor = getContentResolver().query(selectedImage,
filePathColumn, null, null, null);
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
String picturePath = cursor.getString(columnIndex);
cursor.close();

How the codes work for loading image from Gallery Android

I have the codes work for loading images from the gallery but I really do not understand how it works. Here are the codes.
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == RESULT_LOAD_IMAGE && resultCode == RESULT_OK && null != data) { //Browse Gallery is requested
Uri selectedImage = data.getData();
String[] filePathColumn = { MediaStore.Images.Media.DATA };
Cursor cursor = getContentResolver().query(selectedImage, filePathColumn, null, null, null);
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
String picturePath = cursor.getString(columnIndex);
cursor.close();
loadImage(picturePath); //load picture according the path
image_View.setImageBitmap(pic); //Show the selected picture
}
}
Uri selectedImage = data.getData();
Get the uri of selected image from intent
String[] filePathColumn = { MediaStore.Images.Media.DATA };
MediaStore.Images.Media.DATA is constant. I do not understand why do not use String instead of String[]
Cursor cursor = getContentResolver().query(selectedImage, filePathColumn, null, null, null);
I do not understand this line.
cursor.moveToFirst();
Move to the first picture in Gallery.
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
For this one, I always get 0 no matter which picture I choose.
String picturePath = cursor.getString(columnIndex);
Since columnIndex is always 0, then how can it get a different path for different pictures?
Can anyone help me to check whether my explanation is correct and explain the line that I do not understand? Thanks.

1-
Uri selectedImage = data.getData();
This is the statement where you need to read the data passed through another intent which you called earlier via startActivityForResult method. In this case probably you open an intent and let the user select an image, then the URI of the image will be returned to you and you use getData to read that.
2-
String[] filePathColumn = { MediaStore.Images.Media.DATA };
When you want cursors to read something a Content Provider (via ContentResolver) you need to specify which columns you need to read from the database, and the argument you need to pass should be an array of String (whether it has one or more columns you still need to pass an array). MediaStore.Images.Media is a Database Contract which contains constants which you need to use to talk to Content Providers
3-
Cursor cursor = getContentResolver().query(selectedImage, filePathColumn, null, null, null);
Cursors are used for reading data from Content Providers. If you are familiar with other programming languages it is like reading rows from database and your results are stored in Cursors. When you pass URI, you don't need to specify which database to read, ContentResolver will find that out for you (this is an advantage of using content providers)
4-
cursor.moveToFirst();
When you read the desired rows from the database (in this case probably you just selected one image), you need to move the cursor to point to the first entry (row) of the returned results
5-
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
You need to know which column you need to access to read your desired data (in this case file path name). so you ask cursor what is the column index of the file pathname and it will return you the column index. and of course in this case it will be always 0 because you only asked the content provider to return one column (file pathname) so there would be no more data to show other than that
6-
String picturePath = cursor.getString(columnIndex);
and finally this statement asks cursor to get the file pathname located at the index (in this case index 0) so at the end you have your path to file. Note that you can read only one picture data at a time with this method

Cursors store query result records in rows and grant many methods to access and iterate through the records. Also int columnIndex = cursor.getColumnIndex(filePathColumn[0]); is the reason why you always get 0 for your index

How to get a File from a URI?

I select an image from the image gallery in my app. In the onActivityResult it returns an Intent object and I execute the getData() method on it. I get the image URI back. I am now trying to convert that in to a File so I can send it to AWS S3.
This is what I have been trying but it just returns null:
String[] filePathColumn = { MediaStore.Images.Media.DATA };
Cursor cursor = context.getContentResolver().query(contentUri, filePathColumn, null, null, null);
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
String filePath = cursor.getString(columnIndex);
cursor.close();
I also try
File file = new File(imageURI.getPath())
also null. Is this impossible or can somebody help?

supposing your onActivityResult checks in with the Intent object being ReturnedIntent you can do
File f = new File(ReturnedIntent.getData());
or get an inputstream and use it
getContentResolver().openInputStream(ReturnedIntent.getData())
//returns inputstream
what is the essence of this String object String filePath ?

Application Crashes when Load Picture in Listview from Gallery in Android

I am loading pictures in listview taken from camera and directly from gallery. On emulator images from gallery works perfect. But on device when i select first picture it works good. But when i select same picture second time application crashes and no logcat appears.
here is a code:
if (requestCode == UploadFile && resultCode == RESULT_OK && null != data) {
Uri selectedImage = data.getData();
String[] filePathColumn = { MediaStore.Images.Media.DATA };
Cursor cursor = getContentResolver().query(selectedImage,
filePathColumn, null, null, null);
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
String picturePath = cursor.getString(columnIndex);
Bitmap image=(BitmapFactory.decodeFile(picturePath));
cursor.close();
addattachmentsToListView(image);

Normally if it breaks without log you can try to debug it via the Eclipse debugger or similar, may be an option to better understand whats happening.
As far as i can see, your code seems to depend on the fact that there will always be a correct response with at least one result and the [0] column of that result valid.

How to send image through bluetooth in android?

In my application, I open my gallery and pick a picture and then show my image in an image view then I'm supposed to send it through bluetooth.
That's what i've reached :
Uri selectedImage = data.getData();
String[] filePathColumn = {MediaStore.Images.Media.DATA};
Cursor cursor = getContentResolver().query(selectedImage, filePathColumn, null, null, null);
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
String filePath = cursor.getString(columnIndex);
cursor.close();
Bitmap yourSelectedImage = BitmapFactory.decodeFile(filePath);
iv.setImageBitmap(yourSelectedImage);
How to send it through bluetooth?
N.B I've opened my bluetooth and made it also discover-able by other devices .
Please I'll be thankful if u helped me in my assignment =]