HELP - java help on CodeGym

public static class DataAdapter implements RowItem {
        private Customer customer;
        private Contact contact;
        public DataAdapter(Customer customer, Contact contact) {
            this.customer = customer;
            this.contact = contact;
        }
        public String getCountryCode(){
            for (Map.Entry<String, String> pair : countries.entrySet()){
                if (customer.getCountryName() == pair.getValue()){
                    return pair.getKey();
                }
            }
            return null;
        }
        public String getCompany(){
            return customer.getCompanyName();
        }
        public String getContactFirstName(){
            return contact.getName().substring(contact.getName().indexOf(", ")+1);
        }
        public String getContactLastName(){
            String[] name = contact.getName().split("，");
            return name[0];
        }
        public String getDialString(){
            char[] array = contact.getPhoneNumber().toCharArray();
            String number = "+";
            for (char c :array){
                if (c>'0' && c<'9') number += c;
            }
            return number;
        }
    }

getContactFirstName() 方法必须返回包含名字的 String（请参见示例）。应使用 contact 字段的 getName() 方法检索名字和姓氏。为什么通过不了？求帮助。

public static class DataAdapter implements RowItem { private final Customer customer; private final Contact contact; public DataAdapter(Customer customer, Contact contact) { this.customer = customer; this.contact = contact; } @Override public String getCountryCode() { try { String countryName = customer.getCountryName(); String key = countries.entrySet().stream().filter(e -> e.getValue().equals(countryName)).findAny().get().getKey(); return key; } catch (Exception e) { return null; } } @Override public String getCompany() { return customer.getCompanyName(); } @Override public String getContactFirstName() { return contact.getName().split(", ?")[1]; } @Override public String getContactLastName() { return contact.getName().split(", ?")[0]; } @Override public String getDialString() { return "拨号：//" + contact.getPhoneNumber().replaceAll("[()-]", ""); } }