How to change File names in a direction [Java]

Refersnce: https://www.geeksforgeeks.org/how-to-rename-all-files-of-a-folder-using-java/ // Java program to illustrate // how to rename Multiple Files // together using single program import java.io.File; import java.io.IOException; public class rename { public static void main(String[] argv) throws IOException { // Path of folder where files are located String folder_path = "C:\\Users\\Anannya Uberoi\\Desktop\\myfolder"; // creating new folder File myfolder = new File(folder_path); File[] file_array = myfolder.listFiles(); for (int i = 0; i < file_array.length; i++) { if (file_array[i].isFile()) { File myfile = new File(folder_path + "\\" + file_array[i].getName()); String long_file_name = file_array[i].getName(); String[] tokens = long_file_name.split("\\s"); String new_file_name = tokens[1]; System.out.println(long_file_name); System.out.print(new_file_name); // file name format: "Snapshot 11 (12-05-2017 11-57).png" // To Shorten it to "11.png", get the substring which // starts after the first space character in the long // _file_name. myfile.renameTo(new File(folder_path + "\\" + new_file_name + ".png")); } } } }