微信nickname乱码（emoji）及mysql编码格式设置（utf8mb4）解决的过程

保存微信用户昵称时发现，昵称带emoji表情会导致异常

Caused by: java.sql.SQLException: Incorrect string value: '\xF0\x9F\x9A\xAD70...' for column 'nick_name' at row 1
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:964)
        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3973)
        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3909)
        at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2527)
        at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2680)
        at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2501)
        at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1858)
        at com.mysql.jdbc.PreparedStatement.executeUpdateInternal(PreparedStatement.java:2079)
        at com.mysql.jdbc.PreparedStatement.executeUpdateInternal(PreparedStatement.java:2013)
        at com.mysql.jdbc.PreparedStatement.executeLargeUpdate(PreparedStatement.java:5104)
        at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1998)
        at com.alibaba.druid.filter.FilterChainImpl.preparedStatement_executeUpdate(FilterChainImpl.java:2723)
        at com.alibaba.druid.filter.FilterAdapter.preparedStatement_executeUpdate(FilterAdapter.java:1069)
        at com.alibaba.druid.filter.FilterChainImpl.preparedStatement_executeUpdate(FilterChainImpl.java:2721)
        at com.alibaba.druid.filter.FilterAdapter.preparedStatement_executeUpdate(FilterAdapter.java:1069)
        at com.alibaba.druid.filter.FilterEventAdapter.preparedStatement_executeUpdate(FilterEventAdapter.java:491)
        at com.alibaba.druid.filter.FilterChainImpl.preparedStatement_executeUpdate(FilterChainImpl.java:2721)
        at com.alibaba.druid.filter.FilterAdapter.preparedStatement_executeUpdate(FilterAdapter.java:1069)
        at com.alibaba.druid.filter.FilterEventAdapter.preparedStatement_executeUpdate(FilterEventAdapter.java:491)

查询相关资料确定是utf8保存问题,尝试将数据库转为utf8mb4

https://stackoverflow.com/questions/13653712/java-sql-sqlexception-incorrect-string-value-xf0-x9f-x91-xbd-xf0-x9f

连接池为durid,数据库选用阿里云，参考如下

https://segmentfault.com/a/1190000004594385

关键：

1.确定mysql版本5.5.3以上

2.确定mysql-connector-java版本5.1.13以上

3.连接池配置增加如下

4.确定连接串按utf8编码

jdbc:mysql://localhost:3306/dbname?characterEncoding=utf8

5.修改库、表、字段 的编码为utf8mb4

ALTER DATABASE database_name CHARACTER SET = utf8mb4 COLLATE = utf8mb4_unicode_ci;

ALTER TABLE table_name CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci; 

ALTER TABLE table_name CHANGE column_name column_name VARCHAR(191) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;