程序中不应对银行卡号进行硬编码，可以使用配置文件或数据库存储的方式来存储系统所需的数据；并且录入数据时，还可以做加密处理之后再进行数据的录入，从而防止敏感数据泄露。

    1. public class EmployeeDAO {
    2.     private static Map<Integer, Employee> emps = new LinkedHashMap<Integer, Employee>();
    3.     //...
    4.     static {
    5.         emps.put(1001, new Employee(EncryptUtil.encrypt(idCardDAO.getIdByUserId(1001)), "韩信", 32, EncryptUtil.encrypt(phoneDAO.getPhoneById(1001), EncryptUtil.encrypt(bankCardDAO.getIdByUserId(1001))));
    6.         emps.put(1002, new Employee(EncryptUtil.encrypt(idCardDAO.getIdByUserId(1002)), "张良", 40, EncryptUtil.encrypt(phoneDAO.getPhoneById(1002), EncryptUtil.encrypt(bankCardDAO.getIdByUserId(1001))));
    7.         emps.put(1003, new Employee(EncryptUtil.encrypt(idCardDAO.getIdByUserId(1003)), "萧何", 28, EncryptUtil.encrypt(phoneDAO.getPhoneById(1003), EncryptUtil.encrypt(bankCardDAO.getIdByUserId(1001))));
    8.         // ...
    9.     }
    10.     // 雇员信息的增删改查方法
    11.     // ...
    12. }
    13. public class Employee {
    14.     private String id; // 记录雇员的身份证号码
    15.     private String name;
    16.     private int age;
    17.     private String tel; // 记录雇员的电话号码
    18.     private String bankId; // 记录雇员的银行卡卡号
    20.     public Employee() {}
    22.     public Employee(String id, String name, int age, String tel, String bankId) {
    23.         this.id = id;
    24.         this.name = name;
    25.         this.age = age;
    26.         this.tel = tel;
    27.         this.bankId = bankId;
    28.     }
    30.     // Getter and Setter
    31.     // ...
    32. }