android share image from url

An adapted version of @eclass’s answer which doesn’t require use of an ImageView:

Use Picasso to load the url into a Bitmap

public void shareItem(String url) {
    Picasso.with(getApplicationContext()).load(url).into(new Target() {
        @Override public void onBitmapLoaded(Bitmap bitmap, Picasso.LoadedFrom from) {
            Intent i = new Intent(Intent.ACTION_SEND);
            i.setType("image/*");
            i.putExtra(Intent.EXTRA_STREAM, getLocalBitmapUri(bitmap));
            startActivity(Intent.createChooser(i, "Share Image"));
        }
        @Override public void onBitmapFailed(Drawable errorDrawable) { }
        @Override public void onPrepareLoad(Drawable placeHolderDrawable) { }
    });
}

Convert Bitmap into Uri

public Uri getLocalBitmapUri(Bitmap bmp) {
    Uri bmpUri = null;
    try {
        File file =  new File(getExternalFilesDir(Environment.DIRECTORY_PICTURES), "share_image_" + System.currentTimeMillis() + ".png");
        FileOutputStream out = new FileOutputStream(file);
        bmp.compress(Bitmap.CompressFormat.PNG, 90, out);
        out.close();
        bmpUri = Uri.fromFile(file);
    } catch (IOException e) {
        e.printStackTrace();
    }
    return bmpUri;
}