java需要编写一个通用函数，根据用户提供的输入，对地图中的对象进行类型转换

Question

我的问题是，我将有一个映射，并希望编写一个通用方法，这样用户可以传递三个东西（映射、键名、ObjectType），我们将根据用户传递的内容获得类型转换后的值

这是我试过的伪代码。我能够实现其中的一部分

public class Convert {

    public static void main(String args[]) {

        School school = new School();
        school.setName("sa");

        Student st = new Student();
        st.setName("asni");
        school.getStudentSet().add(st);

        Map<String,Object> am = new HashMap<>();
        am.put("St",st ); // value is Student Object
        am.put("S",school.getStudent()); // value is Set<Student>
        am.put("school", school); // value is School Object

        Student s = getvalue(am,"St",Student.class);//this is working
        School sd = getvalue(am,"school",School.class);//this is working
        Student st1 = new Student();
        st1.setName("aaa");
        getvalue(am,"S",Set.class).add(school); //in this school object is getting add which should not happen
        System.out.println();
    }

    public static <T> T getvalue(Map<String,Object> am,String name, Class<T> rtype) {
        return rtype.cast(am.get(name));
    }
}

在根据用户提供的输入进行打字后，我应该得到所有想要的对象