How to check file extension on Android

In my application, when we browse the file from the SD card, the files will be .text, .jpg and mpeg4ie video files.

I want to store each file type into a particular folder. For example, .text files go to the text folder. When I select the file, how do I check the file extension?

I would get the file name as a String, split it into an array with “.” as the delimiter, and then get the last index of the array, which would be the file extension. For example:

public class main {
public static void main(String[] args) {
String filename = "image.jpg";
String filenameArray[] = filename.split("\\.");
String extension = filenameArray[filenameArray.length-1];

Which outputs: