hibernate 解决 java.lang.NoClassDefFoundError: org/hibernate/cfg/Configuration

参考：https://stackoverflow.com/questions/9851528/java-lang-noclassdeffounderror-org-hibernate-cfg-configuration/9853106

You're getting the error because the hibernate libraries are not available to Tomcat. In your picture, below the hibernate library set there is an empty set called 'Web App Libraries' - this is the set your hibernate libraries need to be in.

Right click your project -> Build Path -> Configure Build Path, and remove the hibernate set from the build path. Now import the jars into the WEB-INF/lib folder. Refresh your project and now you should see them listed in the 'Web App Libraries' set (i appreciate this is somewhat annoying that you have to import them into your code base - someone else might know a better way to do this that doesn't involve copying the jars in)

这里要put into lib 一下（虽然以前不put影响的也只是打war包后的项目，没想到这里居然会导致找不到hibernate的jar包，以后只要有新包引入，一定会第一时间put into lib 进去）

然后再测试功能，功能正常