如何从父类获取方法值？运行此代码时出现错误

class Parent {
    public String getInfo() {
        return "Parent Info";
    }
}

class Child extends Parent {
    @Override
    public String getInfo() {
        return "Child Info";
    }
}

class Parent {
    protected String getInfo() { // 或者 public
        return "Parent Info";
    }
}

Parent obj = new Child();
System.out.println(obj.getInfo()); // 输出 "Child Info"

class Parent {
    public Parent() {
        // 初始化代码
    }
}

class Child extends Parent {
    public Child() {
        super(); // 调用父类构造函数
        // 初始化代码
    }
}

class Parent {
    public String getInfo() {
        return "Parent Info";
    }
}

class Child extends Parent {
    @Override
    public String getInfo() {
        return "Child Info";
    }
}

public class Main {
    public static void main(String[] args) {
        Parent obj = new Child();
        System.out.println(obj.getInfo()); // 输出 "Child Info"
    }
}