how to add photo album by spliting urls.

In my application I am adding one section photos of my institute.
In that I want to create folders for different events eg folder for achievements of students,My all students etc.
Here I am uploading photos from local computer or facebook by using ink file picker.
I used "pick multiple" option from ink file picker.
By using it I am getting urls of all images one after other.
I want to split all that urls and store them in array.
And in folder all the urls should be shown in image form.
How can I do this?