Java Utililty Methods Collection Join

if (values.isEmpty()) {
    return "";
Iterator<?> iterator = values.iterator();
if (values.size() == 1) {
    return iterator.next().toString();
StringBuilder builder = new StringBuilder();
...

String[] values = new String[collections.size()];
collections.toArray(values);
return join(delim, 0, collections.size(), values);

if (values == null || values.size() == 0) {
    return "";
StringBuilder s = new StringBuilder();
for (String v : values) {
    s.append(delim);
    s.append(v);
return s.toString().substring(delim.length());

boolean isFirst = true;
String rval = "";
for (T i : items) {
    if (!isFirst)
        rval += delimeter;
    else
        isFirst = false;
    rval += i.toString();
...

if (objects == null || objects.isEmpty()) {
    return EMPTY_STRING;
Iterator<? extends Object> iterator = objects.iterator();
StringBuilder builder = new StringBuilder();
builder.append(iterator.next());
while (iterator.hasNext()) {
    builder.append(delimiter).append(iterator.next());
...

if (objects == null || objects.isEmpty()) {
    return EMPTY_STRING;
Iterator<? extends Object> iterator = objects.iterator();
StringBuilder builder = new StringBuilder();
builder.append(iterator.next());
while (iterator.hasNext()) {
    builder.append(delimiter).append(iterator.next());
...

if (a.isEmpty()) {
    return "";
StringBuilder buffer = new StringBuilder();
for (Object o : a) {
    buffer.append(delimiter);
    buffer.append(o);
return buffer.substring(delimiter.length());

if (isEmpty(items))
    return "";
StringBuilder result = new StringBuilder();
boolean delimOk = !isEmpty(delimiter);
for (Object item : items) {
    if (delimOk && result.length() > 0)
        result.append(delimiter);
    result.append(item);
...

StringBuilder sb = new StringBuilder();
Iterator<?> iterator = filterNulls(objects).iterator();
while (iterator.hasNext()) {
    Object next = iterator.next();
    sb.append(String.valueOf(next));
    if (iterator.hasNext()) {
        sb.append(delimiter);
return sb.toString();

return join(delimiter, parts == null ? EMPTY_ARRAY : parts.toArray());