Error when want to change data in csv file in java

Here is my customer.csv file:

1, Ali,1203456789, Normal
2, Siti,134567890, Normal
3, Bob,1568980765, Normal

I want to change the Normal status of the name I enter to Cased but my code seems got something wrong.And here is my code:

public static void main(String[] args) throws IOException{
    Scanner input = new Scanner(System.in);
    System.out.println("Please enter the customer you want to flag as Cased:");
    String flagCus = input.nextLine();
    ArrayList<String> customersFlagged = new ArrayList<String>();
    List<String> lines = Files.readAllLines(Paths.get("customer.csv"));
    for (int i = 0; i < lines.size(); i++) {
        String[] items = lines.get(i).split(",");
        if (items[1] == flagCus){
            String enterList = items[0] + "," + items[1] + "," + items[2] + "," + "Cased";
            customersFlagged.add(enterList);
        } else{
            String enterList = items[0] + "," + items[1] + "," + items[2] + "," + items[3];
            customersFlagged.add(enterList);
        }
    }

I think the problem is the line if (items[1] == flagCus) ones but I am not sure where got wrong , I have been try to add a " " before my flagCus when doing the if statement but it still goes wrong. Can somebody help me check this code? Thank you for your attention.