泛型

//练习泛型
public class TestFanx {
	public static void main(String[] args) {
		Apple1<Integer> a1 = new Apple1<>();//a1为Integer
		//Apple1<String> a2 = new Apple1<String>();继承了Number只能接受Number
		Apple1<Double> a2 = new Apple1<Double>();
		a1.setSize(10);//设置a1.size
		System.out.println(a1.getSize());//输出a21.size
		a2.setSize(12.25);
		System.out.println(a2.getSize());
		
	}
}

class Apple1<T extends Number>{//继承了Number  设置泛型的上限
	private T size;
	public T getSize() {
		return size;
	}
	public void setSize(T size) {
		this.size = size;
	}
}