Here you can find the source of toLongArray(final List
public static final long[] toLongArray(final List<Long> pItems)
//package com.java2s; import java.util.List; public class Main { public static final long[] toLongArray(final List<Long> pItems) { final long[] out = new long[pItems.size()]; for (int i = out.length - 1; i >= 0; i--) { out[i] = pItems.get(i);//from w w w . ja va2 s . c om } return out; } }