项目启动时报错：
com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure
解决方法（转载）：https://blog.csdn.net/lvoelife/article/details/129284611?spm=1001.2101.3001.6650.1&utm_medium=distribute.pc_relevant.none-task-blog-2%7Edefault%7ECTRLIST%7ERate-1-129284611-blog-81065520.235%5Ev32%5Epc_relevant_increate_t0_download_v2&depth_1-utm_source=distribute.pc_relevant.none-task-blog-2%7Edefault%7ECTRLIST%7ERate-1-129284611-blog-81065520.235%5Ev32%5Epc_relevant_increate_t0_download_v2&utm_relevant_index=2
或者：https://blog.csdn.net/qq_27471405/article/details/80921846?spm=1001.2101.3001.6661.1&utm_medium=distribute.pc_relevant_t0.none-task-blog-2%7Edefault%7ECTRLIST%7ERate-1-80921846-blog-129225733.235%5Ev32%5Epc_relevant_increate_t0_download_v2&depth_1-utm_source=distribute.pc_relevant_t0.none-task-blog-2%7Edefault%7ECTRLIST%7ERate-1-80921846-blog-129225733.235%5Ev32%5Epc_relevant_increate_t0_download_v2&utm_relevant_index=1
- CommunicationsException Communications exceptions failure 数据库communicationsexception communications exceptions mysql communicationsexception jdbc communications communications failure mysql link cjcommunicationsexception communications exceptions sslv3_alert_handshake_failure exceptions handshake communicationsexception indexing failures时报 数据 communicationsexception catalogquerymanager communications communications milliseconds successfully received