Cut up String into Components in Java

The problem

Cut up a given string into totally different strings of equal dimension.

Instance:

Cut up the under string into different strings of dimension #3

'supercalifragilisticexpialidocious'

Will return a brand new string
'sup erc ali fra gil ist ice xpi ali doc iou s'

Assumptions:

String size is at all times larger than 0
String has no areas
Dimension is at all times optimistic

The answer in Java code

Choice 1:

public class InParts {
    public static String splitInParts(String s, int partLength) {
        StringBuilder sb = new StringBuilder();
        char[] c = s.toCharArray();
        int okay = 0;
      
        for (int i=0; i<c.size; i++) {
          sb.append(c[i]);
          if (okay==partLength-1) {
            sb.append(" ");
            okay = -1;
          }
          okay++;
        }
        
        return sb.toString().trim();
    }
}

Choice 2:

public class InParts {
    public static String splitInParts(String s, int partLength) {
       StringBuilder sb = new StringBuilder(s);
       for (int i = partLength++; i < sb.size(); i += partLength){
         sb.insert(i, " ");
       }
       return sb.toString();
    }
}

Choice 3:

public class InParts {
    public static String splitInParts(String s, int partLength) {
        return s.replaceAll("(.{"+partLength+"})(?!$)", "$1 ");
    }
}

Take a look at circumstances to validate our resolution

import static org.junit.Assert.*;
import org.junit.Take a look at;


public class InPartsTest {

    personal static void testing(String precise, String anticipated) {
        assertEquals(anticipated, precise);
    }
   
    @Take a look at
    public void check() {
        System.out.println("Mounted Checks splitInParts");
        String ans = InParts.splitInParts("supercalifragilisticexpialidocious", 3);
        String sol = "sup erc ali fra gil ist ice xpi ali doc iou s"; 
        testing(ans, sol);
        ans = InParts.splitInParts("HelloDude", 3);
        sol = "Hel loD ude"; 
        testing(ans, sol);
        ans = InParts.splitInParts("HelloDude", 1);
        sol = "H e l l o D u d e"; 
        testing(ans, sol);
        ans = InParts.splitInParts("HelloDude", 9);
        sol = "HelloDude"; 
        testing(ans, sol);
    }
}