Unknown initial character set index ‘255‘ received from server.

spring 项目中连接数据库报错：

Unknown initial character set index ‘255’ received from server. Initial client character set can be forced via the ‘characterEncoding’ property.

解决方法：
应该JDBC连接库的URL加上(复制代码里面的)
?useUnicode=true& amp;characterEncoding=utf-8

<bean id="dataSource"
		class="org.springframework.jdbc.datasource.DriverManagerDataSource">
		<property name="driverClassName" value="com.mysql.jdbc.Driver">
		</property>
		<property name="url" value="jdbc:mysql://localhost:3306/tree?useUnicode=true&amp;characterEncoding=utf-8">
		</property>
		<property name="username" value="root"></property>
		<property name="password" value="12345678"></property>
	</bean>

参考：https://blog.csdn.net/si_si_si/article/details/104457315?utm_medium=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-1.control