Java Utililty Methods String Split by Separator

int i = s.indexOf(separator);
List<String> list = new ArrayList<>();
if (i < 0) {
    list.add(s);
    return list;
for (; i >= 0 && i < s.length();) {
    String sub = s.substring(0, i).trim();
...

if (s == null || s.length() == 0)
    return Collections.emptyList();
List<String> list = new ArrayList<>();
int i, pos = 0;
while ((i = s.indexOf(separator, pos)) >= 0) {
    if (i > pos)
        list.add(s.substring(pos, i));
    pos = i + 1;
...

if (s == null)
    return null;
ArrayList<String> parts = new ArrayList<String>();
int beginIndex = 0, endIndex;
while ((endIndex = s.indexOf(separator, beginIndex)) >= 0) {
    parts.add(s.substring(beginIndex, endIndex));
    beginIndex = endIndex + 1;
parts.add(s.substring(beginIndex));
String[] a = new String[parts.size()];
return parts.toArray(a);

if (s == null)
    return null;
ArrayList<String> parts = new ArrayList<String>();
int beginIndex = 0, endIndex;
while ((endIndex = s.indexOf(separator, beginIndex)) >= 0) {
    parts.add(s.substring(beginIndex, endIndex));
    beginIndex = endIndex + 1;
parts.add(s.substring(beginIndex));
String[] a = new String[parts.size()];
return parts.toArray(a);

Vector v = new Vector();
for (int ini = 0, end = 0; ini < s.length(); ini = end + 1) {
    end = s.indexOf(separator, ini);
    if (end == -1)
        end = s.length();
    String st = s.substring(ini, end);
    if (st.length() > 0)
        v.addElement(st);
...

int separatorlen = separator.length();
ArrayList tokenList = new ArrayList();
String tmpString = "" + s;
int pos = tmpString.indexOf(separator);
while (pos >= 0) {
    String token = tmpString.substring(0, pos);
    tokenList.add(token);
    tmpString = tmpString.substring(pos + separatorlen);
...

List<String> result = new ArrayList<>();
int lastIndex = 0;
int index = s.indexOf(separator);
while (index != -1) {
    String substring = s.substring(lastIndex, index);
    if (!substring.equals(separator) && index > 0)
        result.add(substring);
    lastIndex = index + separator.length();
...

if (s == null)
    return null;
List<String> rslt = null;
if (s.isEmpty() || isEmpty(separator)) {
    rslt = new ArrayList<>(1);
    rslt.add(s);
    return rslt;
int start = 0;
int p = start;
do {
    int j = s.indexOf(separator, p);
    if (j == -1) {
        if (rslt == null) {
            rslt = new ArrayList<>(1);
            rslt.add(s);
            return rslt;
        rslt.add(s.substring(start));
        break;
    if (j > 0 && s.charAt(j - 1) == '\\') {
        p = j + 1;
        continue;
    } else {
        if (rslt == null)
            rslt = new ArrayList<String>();
        rslt.add(s.substring(start, j));
        start = j + 1;
        p = start;
} while (true);
return rslt;

int sepLength = separator.length();
if (sepLength == 0)
    return new String[] { s };
ArrayList<String> tokens = new ArrayList<>();
int length = s.length();
int start = 0;
do {
    int p = s.indexOf(separator, start);
...

List<String> ret = new ArrayList<String>();
int p = 0;
while (0 <= (p = src.indexOf(separator))) {
    ret.add(src.substring(0, p));
    src = src.substring(p + 1);
ret.add(src);
return ret;
...