XStream之CannotResolveClassException的问题

String str = "11何"

XStream xStream = new XStream();

xStream.autodetectAnnotations(true);

//xStream.toXml(new People());

People people = (People) xStream.fromXml(str);

System.out.println(people.toString());

如果不要xStream.toXml(new People());就会报CannotResolveClassException异常，如下：

实体类如下，直接复制粘贴的，懒得改

解开注释，就能正常运行并不报异常，奇怪的问题。