Java Utililty Methods List Join

if (list == null) {
    return null;
} else if (list.size() == 0) {
    return "";
} else if (list.size() == 1) {
    return list.get(0);
final StringBuilder builder = new StringBuilder();
...

final StringBuilder text = new StringBuilder(256);
final int size = list.size();
for (int k = 0; k < size; k++) {
    text.append(list.get(k));
    if (k == size - 1) {
        break;
    text.append(sepa);
...

StringBuilder builder = new StringBuilder();
for (String element : path) {
    if (builder.length() != 0) {
        builder.append(delimiter);
    builder.append(element);
return builder.toString();
...

assert strings != null;
if (strings.isEmpty()) {
    return "";
boolean first = true;
final StringBuilder builder = new StringBuilder();
for (final String string : strings) {
    if (!first) {
...

if (strings == null) {
    return "";
return join(strings.toArray(new String[strings.size()]), separator);

final StringBuilder sb = new StringBuilder();
for (final String substring : substrings) {
    if (sb.length() != 0) {
        sb.append(join);
    sb.append(substring);
return sb.toString();
...

final StringBuilder sb = new StringBuilder();
for (final Object v : values) {
    if (sb.length() > 0) {
        sb.append(delimiter);
    sb.append(v);
return sb.toString();
...

final Iterator<String> it = list.iterator();
String result = "";
while (it.hasNext()) {
    result += it.next() + (it.hasNext() ? separator : "");
return result;

final StringBuffer buf = new StringBuffer();
for (final String s : array) {
    if (buf.length() > 0) {
        buf.append(with);
    buf.append(s);
return buf.toString();
...

assert list != null;
Iterator<String> iterator = list.iterator();
assert iterator.hasNext();
StringBuilder buf = new StringBuilder();
buf.append(iterator.next());
while (iterator.hasNext()) {
    buf.append(", ");
    buf.append(iterator.next());
...