Convert an array of primitive longs into a List of Longs

import java.util.Arrays;
import org.apache.commons.lang.ArrayUtils;

List<Long> longs = Arrays.asList(ArrayUtils.toObject(new long[] {1,2,3,4}));

I found it convenient to do using apache commons lang ArrayUtils (JavaDoc, Maven dependency)

import org.apache.commons.lang3.ArrayUtils;
...
long[] input = someAPI.getSomeLongs();
Long[] inputBoxed = ArrayUtils.toObject(input);
List<Long> inputAsList = Arrays.asList(inputBoxed);

it also has the reverse API

long[] backToPrimitive = ArrayUtils.toPrimitive(objectArray);

EDIT: updated to provide a complete conversion to a list as suggested by comments and other fixes.

Since Java 8 you can now use streams for that:

long[] arr = { 1, 2, 3, 4 };
List<Long> list = Arrays.stream(arr).boxed().collect(Collectors.toList());