Java - convert comma separated String to ArrayList

In this post we convert comma separated String to list and back again from list of strings to comma separated String.

1. Convert comma separated String to List<String>

import java.util.Arrays;
import java.util.List;

public class Example1 {

    public static void main(String[] args) {

        String text = "a, b, c";
        List<String> list = Arrays.asList(text.split("\\s*,\\s*"));

        System.out.println(list); // [a, b, c]
    }
}

Output:

[a, b, c]

In this example we use regex: 

\s*,\s*

It removes whitespace from left and right side and split our String by comma.

2. Convert List<String> to comma separated String

To convert list of Strings to comma separated String, we can use Java 8 String.join method on ',' character.

import java.util.Arrays;
import java.util.List;

public class Example2 {

    public static void main(String[] args) {

        List<String> list = Arrays.asList("a", "b", "c");
        String text = String.join(",", list);

        System.out.println(text); // a,b,c
    }
}

Output:

a,b,c