关于SQL Error: 1251 的解决方案

今天在做项目的时候遇到了SQL Error: 1251 Client does not support authentication protocol requested by server; consider upgrading MySQL client 错误

网页先报了一个Servlet错误

Exception

org.apache.jasper.JasperException: 在 [12] 行处理 [/index.jsp] 时发生异常

9:   </head>
10:   
11:   <body>
12:     <jsp:forward page="MessageServlet?method=view"></jsp:forward>
13:   </body>
14: </html>

一开始认为是过滤器配置问题,在检查了过滤器并更改了doFilter代码后查看控制台输出

 public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        if (encoding != null) {
            request.setCharacterEncoding(encoding);
            response.setContentType("text/html; charset=" + encoding);
            System.out.println("过滤器运行中......");
        }else {
            request.setCharacterEncoding("GBK");
            response.setContentType("text/html; charset=GBK");
        }
        chain.doFilter(request, response);
    }

过滤器正在运行
过滤器正在运行
15:49:51,023  WARN JDBCExceptionReporter:71 - SQL Error: 1251, SQLState: 08004
15:49:51,025 ERROR JDBCExceptionReporter:72 - Client does not support authentication protocol requested by server; consider upgrading MySQL client
org.hibernate.exception.JDBCConnectionException: Cannot open connection
	at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:74)
	at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
	at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:29)
	at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:420)
	at org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:144)
	at org.hibernate.jdbc.JDBCContext.connection(JDBCContext.java:119)
	at org.hibernate.transaction.JDBCTransaction.begin(JDBCTransaction.java:57)
	at org.hibernate.impl.SessionImpl.beginTransaction(SessionImpl.java:1326)
	at com.lyq.dao.MessageDao.findPaging(MessageDao.java:114)
	at com.lyq.service.MessageServlet.doPost(MessageServlet.java:75)
	at com.lyq.service.MessageServlet.doGet(MessageServlet.java:28)

查询后得知是这个项目的mysql驱动太老了,8.0后mysql的加密方式就使用了sha2转native

打开mac的系统偏好设置
找到MySql的图标点击Stop MySql Server
选择InitalizeDatabase ,这时候我们选择下面的Use Lagacy Password Encryption,换成老的加密方式并填写密码
接下来我们重新创建数据库和表数据
重新运行,发现控制台出现了 Unknown initial character set index '255' received from server. Initial client character set can be forced via the 'characterEncoding' property.
解决思路:根据提示强制更改characterEncoding属性,然后更改数据库连接参数,如下代码

<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
          "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
          "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <!-- 方言 -->
		<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
		<!--显示sql语句-->
		<property name="hibernate.show_sql">true</property>
		<!--格式化sql-->
		<property name="hibernate.format_sql">true</property>
		<!-- 自动建表 -->
		<property name="hbm2ddl.auto">update</property>
		<!-- 数据库连接 -->
		<property name="connection.url">jdbc:mysql://localhost:3306/db_database16?characterEncoding=gbk</property>
		<!-- 数据库连接用户名 -->
		<property name="connection.username">root</property>
		<!-- 数据库连接密码 -->
		<property name="connection.password">Cc105481</property>
		<!-- 数据库驱动 -->
		<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
		<!-- 映射文件 -->
		<mapping resource="com/lyq/model/Message.hbm.xml"/>
		<mapping resource="com/lyq/model/Revert.hbm.xml"/>
		<mapping resource="com/lyq/model/User.hbm.xml"/>
    </session-factory>
</hibernate-configuration>

至此跑通了这个servlet项目.

原文地址：https://www.cnblogs.com/MrKeen/p/12575325.html