Java Utililty Methods List to Double Array

if (stringArray == null) {
    return null;
double[] result = new double[stringArray.size()];
for (int i = 0; i < stringArray.size(); i++) {
    try {
        if (stringArray.get(i) != null) {
            result[i] = Double.parseDouble(stringArray.get(i));
...

double[] ds = new double[values.size()];
for (int i = 0; i < ds.length; i++) {
    ds[i] = Double.parseDouble(values.get(i));
return ds;

List<Double> result = new ArrayList<Double>(array.length);
for (int i = 0; i < array.length; i++) {
    result.add(i, array[i]);
return result;

List<Double> list = new ArrayList<Double>(array.length);
for (double el : array)
    list.add(el);
return list;

List<Double> doubleList = new ArrayList<Double>(doubleArray.length);
for (double currDouble : doubleArray) {
    doubleList.add(currDouble);
return doubleList;

List<Double> ret = new ArrayList<Double>();
for (Double d : in)
    ret.add(d);
return ret;

List<Double> doubleList = null;
if (array != null) {
    doubleList = new ArrayList<Double>(array.length);
    for (E e : array) {
        if (e != null) {
            try {
                doubleList.add(Double.parseDouble(e.toString()));
            } catch (NumberFormatException nfe) {
...

return values;

List<Double> doubleList = new ArrayList<Double>();
for (Integer val : list) {
    doubleList.add(val.doubleValue());
return doubleList;

List<Double> out = new ArrayList<Double>(array.length);
for (int i = 0; i < array.length; i++) {
    if (array[i] == null)
        throw new RuntimeException("Null value in position " + i);
    out.add(Double.parseDouble(array[i]));
return out;