java 父类转换成子类的方法

/* 父类转换成子类的特点:
1:父类转换成子类不能自动完成
2:父类转换成子类的前提是父类的真身是这个子类
3:如果这个父类的真身是子类B,不能强制转换成子类A,只能转换成B.
*/
class Teacher2{
String name = “王鹏”;
public void Teach(){
System.out.println(name+“在教课”);
}
}
class JavaTeacher extends Teacher2{
public void Teach(){
System.out.println(name+“在ks”);
}
//read阅读
public void Read(){
System.out.println(name+“在图书馆看书”);
}
}
class EnglishTeacher extends Teacher2{
public void Teach(){
System.out.println(name+“在教英语”);
}
}
public class TestTeacher2{
public static void main(String[] args){
Teacher2 t = new JavaTeacher();

		//t.name = "李静";
		t.Teach();
		//强制转换 ,把真身是JavaTeacher的父类转回JavaTeacher的子类
		JavaTeacher jt = (JavaTeacher)t;
		jt.Read();
		//3:如果这个父类的真身是子类B,不能强制转换成子类A,只能转换成B.
		Teacher2 e = new EnglishTeacher();
		
		EnglishTeacher et = (EnglishTeacher)e;
		et.Teach();
		
		}

}