If issue remains, please specify the exact problem you have.
UPD: most likely the issue is with the encoding on a client side, so the character_set_server property will not help here. MySQL jdbc driver also lets user to change encoding on a client side, and the option for this is characterEncoding which can be set in Advanced tab of the Data Source properties dialog. Please try to set it to this encoding.
character_set_server = utf8mb4 must be specified on the server side (i. e. in my.cnf), under the [mysqld] section.
Generally, if both character_set_server and character_set_database (for the given database) are set to utf8mb4, that's it, utf8mb4 should just work.
If, on the other hand, your character_set_server is set to some other value, but character_set_database is still utf8mb4 (i. e. the database can still hold utf8mb4 data), you need to additionally "cast" your parameters and literals, e.g.: INSERT INTO unicode_test (value) VALUES (_utf8mb4 '𤭢').
Additionally, if your character_set_server is set to neither utf8 nor utf8mb3 nor utf8mb4, you need to explicitly force your JDBC connection into Unicode mode, by setting the characterEncoding connection property to UTF-8.
Hello Tuan,
Try to append database url connection string with "character_set_server=utf8mb4". See http://stackoverflow.com/a/10959780/2000323
If issue remains, please specify the exact problem you have.
UPD: most likely the issue is with the encoding on a client side, so the character_set_server property will not help here. MySQL jdbc driver also lets user to change encoding on a client side, and the option for this is characterEncoding which can be set in Advanced tab of the Data Source properties dialog. Please try to set it to this encoding.
character_set_server = utf8mb4 must be specified on the server side (i. e. in my.cnf), under the [mysqld] section.