发布时间：2012-12-10 20:09:25
hibernate 联合主键出现的问题?Exception in thread "main" org.hibernate.id.IdentifierGenerationException: null id generated for:class com.example.hibernate.model.Teacher原因： NULL 不能作为数据库Teacher表达的主键 猜测可能是由于在测试时没有插入主键数据解决： 检查程序 发现程序果然没有插入联合主键的数据 ?插入联合主键数据后重新运行程序后正常。......【阅读全文】
发布时间：2012-11-24 16:10:06
structs2 对ActionContext valueStack stack context 的理解......【阅读全文】
py超级菜鸟2013-03-10 23:26
Within a character list, a "range expression" consists of two
characters separated by a hyphen. It matches any single character that
sorts between the two characters, using the locale's collating sequence
and character set. For example, in the default C locale, `[a-dx-z]' is
equivalent to `[abcdxyz]'. Many locales sort characters in dictionary
order, and in these locales, `[a-dx-z]' is typically not equivalent to
`[abcdxyz]'; instead it might be equivalent to `[aBbCcDdxXyYz]', for
example. To obtain the traditional interpretation of bracket
expressions, you can use the C locale by setting the `LC_ALL'
environment variable to the value `C'.
