启动后，就报这个错误，实际上没做什么操作

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[WARN]-[Thread: Task-Thread-for-com.mchange.v2.async.ThreadPerTaskAsynchronousRunner@32f246b2]-[com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask.run()]: com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@39736dd4 -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception: 

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Data source rejected establishment of connection,  message from server: "Too many connections"