Use jdbc to handle MySQL's utf8mb4 character set (transfer)

Original link address:

http://blog.51cto.com/11931236/2057929

Server Solutions

When consulting the official MySQL documentation, the following official solutions are given to support utf8 to utf8mb4

https://dev.mysql.com/doc/refman/5.7/en/charset-unicode-conversion.html

The above steps are only for server-side configuration.

Additional special handling is required for the client

Because my current project is written in JAVA and uses JDBC to connect to operate the database, the following is the solution for JDBC operation

Configuration before JDBC URL

String url = "jdbc:mysql://HOST:PORT/DATABASE?useUnicode=true&characterEncoding=UTF-8";

In the connection configuration, declare the character encoding of UTF-8. In terms of current storage requirements, an error will be reported when storing emoji strings. Even if the server database is set to the utf8mb4 character set type

The client is modified to the following configuration

String url = "jdbc:mysql://HOST:PORT/DATABASE?useUnicode=true&characterEncoding=utf8mb4";

An error occurs when the client connects, the character set is not supported

Solutions to the above problems

Change the connection configuration to

String url = "jdbc:mysql://HOST:PORT/DATABASE";

At the same time, the database configuration file my.cnf is modified accordingly

[client]default-character-set=utf8mb4[mysql]default-character-set=utf8mb4[mysqld]character-set-client-handshake=FALSEcharacter-set-server=utf8mb4collation-server=utf8mb4_unicode_ci

Restart the service MySQL service

The problem is solved here