Java Utililty Methods List Join

List<String> list = new ArrayList<String>();
for (String cur : list1) {
    if (!list.contains(cur)) {
        list.add(cur);
for (String cur : list2) {
    if (!list.contains(cur)) {
...

List<String> join = new ArrayList<String>(list1);
join.addAll(list2);
return join;

return join(lst, start, end, " ");

if (lst == null)
    return "";
StringBuilder str = new StringBuilder();
Iterator<String> iter = lst.iterator();
while (iter.hasNext()) {
    str.append(iter.next());
    if (iter.hasNext()) {
        str.append(separator);
...

StringBuilder builder = new StringBuilder();
for (int i = 0; i < members.size(); ++i) {
    if (i != 0) {
        builder.append(",");
    if (quote) {
        builder.append('"').append(members.get(i)).append('"');
    } else {
...

StringBuilder sb = new StringBuilder();
for (String sCurrStr : p_sStrList) {
    if (sb.length() > 0)
        sb.append(p_sDelimiter);
    sb.append(sCurrStr);
return sb.toString();

Iterator<String> it = parts.iterator();
StringBuilder builder = new StringBuilder();
while (it.hasNext()) {
    String part = it.next();
    builder.append(part);
    if (it.hasNext()) {
        builder.append(separator);
return builder.toString();

if (paths == null || paths.isEmpty()) {
    return null;
StringBuilder sb = new StringBuilder();
for (int i = 0; i < paths.size(); i++) {
    if (i == 0) {
        sb.append(trimTrailingSlash(paths.get(i)));
    } else {
...

StringBuilder sb = new StringBuilder();
for (int i = 0; i < s.size() - 1; i++) {
    sb.append(s.get(i));
    sb.append(delim);
if (s.size() > 0)
    sb.append(s.get(s.size() - 1));
return sb.toString();
...

String r = s.get(0);
for (int i = 1; i < s.size(); i++) {
    r += sep + s.get(i);
return r;