Java Convert comma-separated String to a List

Java examples to show you how to convert a comma-separated String into a List and vice versa.

1. Comma-separated String to List

package com.mkyong.utils;
import java.util.Arrays;
import java.util.List;
public class TestApp1 {
    public static void main(String[] args) {
        String alpha = "A, B, C, D";
		//Remove whitespace and split by comma 
        List<String> result = Arrays.asList(alpha.split("\\s*,\\s*"));
        System.out.println(result);

Output

[A, B, C, D]

2. List to Comma-separated String

No need to loop the List, uses the new Java 8 String.join

package com.mkyong.utils;
import java.util.Arrays;
import java.util.List;
public class TestApp2 {
    public static void main(String[] args) {
        List<String> list = Arrays.asList("A", "B", "C", "D");
        String result = String.join(",", list);
        System.out.println(result);

Output

A,B,C,D

References

1. StringJoiner JavaDoc
2. Java 8 – StringJoiner example