问题描述：

java.sql.SQLException: Incorrect string value: '\xF0\x9F\x90\xBB' for column 'nickName' at row 1
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1094)
        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4226)
        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4158)
        at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2615)
        at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2776)
        at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2840)
        at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2082)
        at com.mysql.jdbc.PreparedStatement.execute(PreparedStatement.java:1302)
        at sun.reflect.GeneratedMethodAccessor49.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.apache.ibatis.logging.jdbc.PreparedStatementLogger.invoke(PreparedStatementLogger.java:55)
        at com.sun.proxy.$Proxy58.execute(Unknown Source)
        at org.apache.ibatis.executor.statement.PreparedStatementHandler.update(PreparedStatementHandler.java:41)
        at org.apache.ibatis.executor.statement.RoutingStatementHandler.update(RoutingStatementHandler.java:66)
        at org.apache.ibatis.executor.SimpleExecutor.doUpdate(SimpleExecutor.java:45)
        at org.apache.ibatis.executor.BaseExecutor.update(BaseExecutor.java:100)
        at org.apache.ibatis.executor.CachingExecutor.update(CachingExecutor.java:75)

解决方法：
1.建表的时候添加如下限制：

ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;

例如：

DROP TABLE IF EXISTS `user_dymatic_info`;
CREATE TABLE `user_dymatic_info` (
  `_id` int(11) NOT NULL AUTO_INCREMENT,
  `content` longtext NOT NULL,
  `time` varchar(60) NOT NULL DEFAULT '',
  `slug` varchar(60) NOT NULL DEFAULT '',
  `dymatic_type` varchar(60) NOT NULL DEFAULT '',
  `extra_content` varchar(500) NOT NULL DEFAULT '',
  PRIMARY KEY (`_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;

2.修mysql配置文件中的my.cnf如下：
1）、在[client]添加

default-character-set=utf8mb4

2)、在[mysql]中添加

default-character-set = utf8mb4

3）、在底部[mysqld]添加

character-set-client-handshake = FALSE
character-set-server = utf8mb4
collation-server = utf8mb4_unicode_ci
init_connect='SET NAMES utf8mb4'

重启mysql服务，service mysql stop； service mysql start；问题解决。
造成这个问题的原因（网上找的）：
mysql中规定utf8字符的最大字节数是3，但是某些unicode字符转成utf8编码之后有4个字节，导致出错。