摘要：
1 public abstract class Car { 2 3 public abstract String getCarName(); 4 5 } 1 public class BYD extends Car { 2 3 @Override 4 public String getCarName 阅读全文
摘要：
1 public class Student { 2 3 private static Student student = null; 4 private String name = ""; 5 6 private Student() {// 把构造方法私有化 7 8 } 9 10 public s 阅读全文