LeetCode - Simplify Path

Simplify Path

public String simplifyPath(String path) {
        if(path == null || path.length() == 0) return path;
        String[] arr = path.split("/");
        Stack<String> stack = new Stack<String>();
        for(int i = 0; i < arr.length; i++){
            if(arr[i].length() > 0){
                if(arr[i].equals("..")){
                    if(!stack.isEmpty()) stack.pop();
                } else if (arr[i].equals(".")){
                    continue;
                } else{
                    stack.push(arr[i]);
                }
            }
        }
        StringBuilder sb = new StringBuilder();
        while(!stack.isEmpty()){
            String cur = stack.pop();
            sb.insert(0, cur);
            sb.insert(0, "/");
        }
        return sb.length() > 0 ? sb.toString() : "/"; 
    }