preface

When you encounter problems, don’t ask others urgently. Unless you are in a hurry, analyzing and solving the causes of the problems yourself is an intuitive embodiment of our ability. If Baidu can’t, you can use Google.

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Use JDBC to connect to the database. The driver loading, URL, user name and password are all correct, but you can’t connect to the database anyway. Check the error message slowly and say it’s a character set problem.

Error message

Cannot create PoolableConnectionFactory (Unknown initial character set index '255' received from server. Initial client character set can be forced via the 'characterEncoding' property.)

Original link information

jdbc:mysql://xxxxxx:3306

After modification

jdbc:mysql://xxxxxx:3306?useUnicode=true&characterEncoding=utf8

good job