@Contract("null, _, _ -> null")
private static String toCanonicalPath(
@Nullable String path, char separatorChar, boolean removeLastSlash) {
if (path == null || path.isEmpty()) {
return path;
} else if (".".equals(path)) {
return "";
}
path = path.replace(separatorChar, '/');
if (path.indexOf('/') == -1) {
return path;
}
int start = pathRootEnd(path) + 1, dots = 0;
boolean separator = true;
StringBuilder result = new StringBuilder(path.length());
result.append(path, 0, start);
for (int i = start; i < path.length(); ++i) {
char c = path.charAt(i);
if (c == '/') {
if (!separator) {
processDots(result, dots, start);
dots = 0;
}
separator = true;
} else if (c == '.') {
if (separator || dots > 0) {
++dots;
} else {
result.append('.');
}
separator = false;
} else {
if (dots > 0) {
StringUtil.repeatSymbol(result, '.', dots);
dots = 0;
}
result.append(c);
separator = false;
}
}
if (dots > 0) {
processDots(result, dots, start);
}
int lastChar = result.length() - 1;
if (removeLastSlash && lastChar >= 0 && result.charAt(lastChar) == '/' && lastChar > start) {
result.deleteCharAt(lastChar);
}
return result.toString();
}
