eclipse转intellij idea -java报错

p>idea导入了之前eclipse的maven项目，偶尔会出现以下错误，然后项目进行build和Invalidate仍然无效，但是在eclipse项目下运行无异常。但是在eclipse下进行clean后，idea又能够重新启动，请问这是啥问题？

2017-06-22 10:12:49 xxl-job-executor-example [com.alibaba.druid.pool.DruidDataSource]-[RMI TCP Connection(5)-127.0.0.1]-[init]-[616]-[ERROR] init datasource error com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.