Class

/*
     * Constructor. Only the Java Virtual Machine creates Class
     * objects.
     */
    private Class() {}
Class類的構造函數是私有的，只有jvm能new Class 不能 new Class<Cat>();

/**
 * Run Time Type Information
 */
public class Client {
	public static void main(String[] args) {
		Object obj = new Client();
		/**class com.RTTI.test.Client*/
		System.out.println(obj.getClass());
		System.out.println(obj.getClass().getName());
		System.out.println(int.class);
		
		Class<Integer> genri = int.class;
		genri = Integer.class;
		/**
		 * error:Type mismatch: cannot convert from Class<Integer> to Class<Number>
		*
		Class<Number> genericNameer = int.class;
		 */
		Class<?> generic = int.class;
		/**
		 * 接受繼承自Number的類型 的 class，而不是繼承與Number.class的 Class類型
		 */
		Class<? extends Number> bounded = int.class;
		Building b = new House();
		Class<House> houseType = House.class;
		houseType.cast(b);
		ClassTest(houseType);
	}
	public static void ClassTest(Class<? extends House> clazz) {
		try {
			Object obj = clazz.newInstance();
			if(obj instanceof House) {
				System.out.println("obj instanceof House=true");
				House house = clazz.cast(obj);
				house.ff();
			}else if(obj instanceof Building) {
				System.out.println("obj instanceof Building=true");
				Building b = (Building)obj;
				b.f();
			}
			if(clazz.isInstance(obj)) {
				System.out.println("House Instance");
			}
			
		} catch (InstantiationException e) {
			e.printStackTrace();  
		} catch (IllegalAccessException e) {
			e.printStackTrace();
		} 
	}
}
class Building{
	public void f() {
		System.out.println("Building f()");
	}
}
class House extends Building{
	@Override
	public void f() {
		System.out.println("House f()");
	}
	public void ff() {
		System.out.println("House ff()");
	}
};