Java：XStream 下划线

Why do field names suddenly have double underscores in the generated XML?

XStream maps Java class names and field names to XML tags or attributes. Unfortunately this mapping cannot be 1:1, since some characters used for identifiers in Java are invalid in XML names. Therefore XStream uses an XmlFriendlyNameCoder to replace these characters with a replacement. By default this NameCoder uses an underscore as escape character and has therefore to escape the underscore itself also. You may provide a different configured instance of the XmlFriendlyNameCoder or a complete different implementation like the NoNameCoder to prevent name coding at all. However it is your responsibility then to ensure, that the resulting names are valid for XML.

1、1.4及以后 

2、1.4之前

3、注册到spring mvc