使用List 参数重载Java函数

如果您使两个类都实现一个通用接口，

interface CustomerNumber {    String getCustomerNumber();}public class Customer implements CustomerNumber {  ...  public String getCustomerNumber();  ...}public class Applicant implements CustomerNumber {   ....   private Customer c;   public Customer getCustomer() { return c; }   public String getCustomerNumber() { return getCustomer().getCustomerNumber(); }   ...}

那么您也许可以只用一个方法就能做您想做的事情：

public void processCustomerNumbers(List<? extends CustomerNumber> appList) {    for (Customer c: appList) {        processCustomerNumber(c.getCustomerNumber());    }}