Java: How to convert String[] to List or Set [duplicate]

Answer 1

The easiest way would be:

String[] myArray = ...;
List<String> strs = Arrays.asList(myArray);

using the handy Arrays utility class. Note, that you can even do

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

Answer 2

Whilst this isn't strictly an answer to this question I think it's useful.

Arrays and Collections can bother be converted to Iterable which can avoid the need for performing a hard conversion.

For instance I wrote this to join lists/arrays of stuff into a string with a seperator

public static <T> String join(Iterable<T> collection, String delimiter) {
    Iterator<T> iterator = collection.iterator();
    if (!iterator.hasNext())
        return "";

    StringBuilder builder = new StringBuilder();

    T thisVal = iterator.next();
    builder.append(thisVal == null? "": thisVal.toString());

    while (iterator.hasNext()) {
        thisVal = iterator.next();
        builder.append(delimiter);
        builder.append(thisVal == null? "": thisVal.toString());
    }

    return builder.toString();
}

Using iterable means you can either feed in an ArrayList or similar aswell as using it with a String... parameter without having to convert either.

Answer 3

Collections.addAll provides the shortest (one-line) receipt

Having

String[] array = {"foo", "bar", "baz"}; 
Set<String> set = new HashSet<>();

You can do as below

Collections.addAll(set, array);