为什么封装出现问题，求各位大神指点

class Telphone

{

        private float screen;

        private float cpu;

        private float mem;

public float getScreen()

{

return screen;

}

public void setScreen(float newScreen)

{

screen=newScreen;

}

public Telphone()

{

System.out.println("无参");

}

public Telphone(float newScreen,float newCpu,float newMem)

{

screen=newScreen;

cpu=newCpu;

    mem=newMem;

System.out.println("有参");

   }

}

class InitailTelphone

{

public static void main(String[] args)

{

Telphone phone=new Telphone();

Telphone phone2=new Telphone(5.0f,1.4f,2.0f);

 phone2.setScreen(6.0f);

System.out.println("screen:"+phone2.getScreen());

}

}