JavagetClass()方法
示例
该getClass()方法可用于查找对象的运行时类类型。请参阅以下示例：
public class User {
private long userID;
private String name;
public User(long userID, String name) {
this.userID= userID;
this.name= name;
}
}
public class SpecificUser extends User {
private String specificUserID;
public SpecificUser(String specificUserID, long userID, String name) {
super(userID, name);
this.specificUserID= specificUserID;
}
}
public static void main(String[] args){
User user = new User(879745, "John");
SpecificUser specificUser = new SpecificUser("1AAAA", 877777, "Jim");
User anotherSpecificUser = new SpecificUser("1BBBB", 812345, "Jenny");
System.out.println(user.getClass()); //Prints "class User"
System.out.println(specificUser.getClass()); //Prints "class SpecificUser"
System.out.println(anotherSpecificUser.getClass()); //Prints "class SpecificUser"
}该getClass()方法将返回最特定的类类型，这就是为什么在getClass()调用时anotherSpecificUser，返回值的classSpecificUser原因是它比继承树低User。
值得注意的是，尽管该getClass方法声明为：
public final native Class<?> getClass();
调用返回的实际静态类型getClass是Class<?extendsT>whereT是getClass被调用对象的静态类型。
即以下将编译：
Class<? extends String> cls = "".getClass();