Java 向下类型转换

public class Test {    public static void main(String[] args) {        Parent p = new Child();        Child child = (Child) p;//这种叫做向下类型转换，父类强转成子类，父在上、子在下，故叫做向下类型转换        child.single();    }}class Parent {    public void single() {        System.out.println("Parent single");    }}class Child extends Parent {    public void single() {        System.out.println("child single");    }}