Convert String into comma separated List in Java

At first, set a list with string values −

List<String> myList = new ArrayList<>(
Arrays.asList("One", "Two", "Three", "Four"));

Now, use String.join() to set them as a comma separated list −

String str = String.join(", ", myList);

Example

Following is the program to convert string into comma separated List in Java −

import java.util.*;
public class Demo {
   public static void main(String args[]) {
      List<String> myList = new ArrayList<>(Arrays.asList("One", "Two", "Three", "Four"));
      System.out.println("List = " + myList);
      // comma separated
      String str = String.join(", ", myList);
      System.out.println("String (Comma Separated) = " + str);
   }
}

Output

List = [One, Two, Three, Four]
Comma separated String: One, Two, Three, Four