我不确定您是否有旧版本的 IntelliJ IDEA，但如果我转到菜单 File → Settings... → 检查 → 序列化问题 → 未启用serialVersionUID"的可序列化类，您提供的类给我警告.

I am not sure if you have an old version of IntelliJ IDEA, but if I go to menu File → Settings... → Inspections → Serialization issues → Serializable class without 'serialVersionUID'` enabled, the class you provide give me warnings.

如果我尝试第一堂课，我会看到:

If I try the first class I see:

顺便说一句:直到我将 { } 添加到每个类的末尾以修复编译错误后，它才向我显示警告.

BTW: It didn't show me a warning until I added { } to the end of each class to fix the compile error.