simplify path

public String (String path) {
    if (path == null || path.length() == 0)
        return path;
    Stack<String> stack = new Stack<String>();
    String[] strs = path.split("/");
    
    // (/a/./b/../../c/).split("/")
    // -> {, a, ., b, .., .., c}
    for (String str : strs) {
        if (str.equals("") || str.equals("."))
            continue;
        else if (str.equals("..")) {
            if (!stack.isEmpty())
                stack.pop();
        }
        else
            stack.push(str);
    }
    StringBuilder sb = new StringBuilder();
    while (!stack.isEmpty()) {
        sb.insert(0,stack.pop());
        sb.insert(0, "/");
    }
    return sb.length() == 0 ? "/" : sb.toString();
}