Here we will see how to convert List to String comma separated values using Java 8.

List to String Comma Separated:

Let’s take a simple java List<String>, filled with Strings of elements.

1. List to String using String.join():

List<String> countries = Arrays.asList("Java","Spring","Hibernate","Python","C");
String countrieswithComma = String.join(",",countries);
System.out.println(countrieswithComma);

Output:

Java,Spring,Hibernate,Python,C

2. List to String comma separate using Streams:

Java 8 streams are beneficial to collect data in different formats.

List<String> countries = Arrays.asList("Java","Spring","Hibernate","Python","C");
String countrieswithComma = countries.stream().collect(Collectors.joining(","));
System.out.println(countrieswithComma);

Output:

Java,Spring,Hibernate,Python,C

3. List to comma separate strings using Java 7:

If you are using legacy java version (before Java 8), you can even convert the list to string comma separate values by using the following logic.

List<String> countries = Arrays.asList("Java","Spring","Hibernate","Python","C");
StringBuffer buffer = new StringBuffer();
for (String country : countries){
     buffer.append(country).append(",");
}
buffer.deleteCharAt(buffer.lastIndexOf(",")); // To remove leading comma
countrieswithComma= buffer.toString();
System.out.println(countrieswithComma);

Output:

Java,Spring,Hibernate,Python,C

References:

• Java 8 Streams
• Java 8 Stream to List

Happy Learning 🙂