[解决方法] Java-Class.forName() 反射/映射子类 并转化为父类/接口

    public TheParentClass getSubClass(String subClassName)
    {
        Class<?> classSub = Class.forName(subClassName);
        TheParentClass newClass = classSub.asSubclass(TheParentClass.class).newInstance();

        // newClass.doMethod();
        return newClass;
    }

public TheParentClass getSubClass(String subClassName)
{

if(subClassName=="SubClassA"); 
{
     return  new SubClassA();
}
else if(subClassName=="SubClassB"); 
{
     return  new SubClassB();
}
//......
else
{
return null;
}
}