LookupField doubts for setting Value

I have to setvalue in lookuppickerfield which is in not editable mode

Its sample example

private LookupPickerField customer;

private DataManager dataManager;

public void init(Map<String, Object> params) {
      LSD lsd = (LSD) params.get("lsd");
      String[] id = lsd.getCustomer().toString().split("Customer-");
      String value = id[1];
      String[] finalValues = value.split("\\[");
      String result = finalValues[0].trim();
      UUID resultValue = UUID.fromString(result);
      Customer fields = getCustomer(resultValue);

private Customer getCustomer(UUID customerId){
    return dataManager.load(Customer.class)
            .query("select p from cpreading$Customer p where p.id = :customerId")
            .parameter("customerId", customerId)