a2. Class clz = Class.forName("类的完整路径");
a3. Class clz = 对象名.getClass();
父接口类型 实例名 = (父接口类型)clz.newInstance();
public static Mobile createMobile(String className){
Class clz = Class.forName(className);
mobile = (Mobile)clz.newInstance();
}catch (IllegalAccessException e) {