java游戏核心源代码 对于喜欢java游戏的可以看看 和有帮助的

				package services;								public class InvoicerImpl implements Invoicer {								    // this class not implemented for sake of brevity								    public void invoiceCustomer(long customerNumber, String customerEmail, float amount) {				        throw new UnsupportedOperationException();				    }								}