<property name="connectionInitSqls" value="set names utf8mb4;" />

useUnicode=true&amp&allowMultiQueries=true&autoReconnect=true&charset=utf8mb4

my.ini

[client]
default-character-set = utf8mb4  
 
[mysql]
default-character-set = utf8mb4  
 
[mysqld]
character-set-client-handshake = FALSE
character-set-server = utf8mb4
collation-server = utf8mb4_unicode_ci
init_connect='SET NAMES utf8mb4'  

ALTER DATABASE 数据库名 CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;

alter table 表名 convert to character set utf8mb4 collate utf8mb4_bin;