为什么java web 项目在本地可以运行，在服务器却报错。

Question

在本机上运行能运行项目，但是去服务器之后，就报错，大概是连接不上数据库。
七月 10, 2018 5:40:55 下午 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet [springmvc] in context with path [/happyCircle] threw exception [Request processing failed; nested exception is org.apache.shiro.authc.AuthenticationException: Authentication failed for token submission [org.apache.shiro.authc.UsernamePasswordToken - 222, rememberMe=false]. Possible unexpected error? (Typical or expected login exceptions should extend from AuthenticationException).] with root cause
java.lang.NoClassDefFoundError: com/mongodb/MongoException$DuplicateKey
at org.springframework.data.mongodb.core.MongoExceptionTranslator.translateExceptionIfPossible(MongoExceptionTranslator.java:51)
at org.springframework.data.mongodb.core.MongoTemplate.potentiallyConvertRuntimeException(MongoTemplate.java:1829)
at org.springframework.data.mongodb.core.MongoTemplate.executeFindMultiInternal(MongoTemplate.java:1712)
at org.springframework.data.mongodb.core.MongoTemplate.doFind(MongoTemplate.java:1523)
at org.springframework.data.mongodb.core.MongoTemplate.doFind(MongoTemplate.java:1507)
at org.springframework.data.mongodb.core.MongoTemplate.find(MongoTemplate.java:532)
at org.springframework.data.mongodb.core.MongoTemplate.find(MongoTemplate.java:523)
at com.happyCircle.admin.dao.impl.TUserDaoImpl.login(TUserDaoImpl.java:241)
at com.happyCircle.admin.service.impl.TUserServiceImpl.login(TUserServiceImpl.java:53)
at com.happyCircle.admin.shiro.MyRealm.doGetAuthenticationInfo(MyRealm.java:99)

Answer 1

java.lang.NoClassDefFoundError: com/mongodb/MongoException 这个错误不就说明了么，编译能找到该类，运行找不到该类，这你就要看他在哪里调用这个类的，看看是不是没有引入进来导致报错