class Rootb
{
int x = 1;


public Rootb(int i)
{
}


public int getI()
{
return x;
}


public void setI(int x)
{
this.x = x;
}
}


class Stemb extends Rootb
{
private int x = 2;


public Stemb(int i)
{
super(i);
}


public int getI()
{
return x;
}


public void setI(int x)
{
this.x = x;
}
}


public class Test
{
public static void main(String args[])
{
Rootb stb = new Stemb(47);
stb.x = 3;
System.out.println(stb.x);
System.out.println(((Stemb) stb).getI());


System.out.println(stb.getI());
System.out.println(((Stemb) stb).getI());


stb.setI(5);
System.out.println(stb.x);
System.out.println(((Stemb) stb).getI());


System.out.println(stb.getI());
System.out.println(((Stemb) stb).getI());


Stemb rootb = (Stemb) new Rootb(47);
rootb.setI(3);
System.out.println(rootb.getI());
System.out.println(((Rootb) rootb).x);


}

}

3
2
2
2
3
5
5
5
Exception in thread "main" java.lang.ClassCastException: Rootb cannot be cast to Stemb
at Test.main(Test.java:59)

結論：java屬性不覆蓋，方法覆蓋。