hibernate mappingexception未知实体的配置异常

Question

我是hibernate的初学者。我正在关注来自http://javapostsforlearning.blogspot.in/2013/01/hibernate-hello-world-example-in-eclipse.html的这个hello world教程 但我面临以下例外：

Exception in thread "main" org.hibernate.MappingException: invalid configuration
    at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:2018)
    at org.hibernate.cfg.Configuration.configure(Configuration.java:1935)
    at org.hibernate.cfg.Configuration.configure(Configuration.java:1914)
    at org.arpit.javapostsforlearning.Main.main(Main.java:14)

请帮我解决这个问题。