full description of program code

import java.util.*; class StringExample6 { public static void main(String[] args) { Scanner input=new Scanner(System.in); System.out.println("Enter string:"); String str=input.nextLine(); StringTokenizer stk=new StringTokenizer(str); String vowels="",consonants=""; while(stk.hasMoreTokens()){ String token=stk.nextToken(); if(token.startsWith("a")||token.startsWith("e")||token.startsWith("i")||token.startsWith("o")||token.startsWith("u")){ vowels+=token+" "; } else if(!token.startsWith("a")||!token.startsWith("e")||!token.startsWith("i")||!token.startsWith("o")||!token.startsWith("u")){ consonants+=token+" "; } } System.out.println("Second Output: "+vowels.concat(consonants)); } }

above a program code of reverse string program in this program user input a string and print all vowel worts at start and end all consonant. i've a problem that plz describe me full description of this code thanks