解决Java异常java.sql.SQLException: Unexpected exception encountered during query.

问题

在学习Java的servlet过程中，学习到MySQL连接的部分时，配置都正确的情况下，一直没有得到想要的结果。网页这边一直是200，换浏览器也是200，但是就是空白，一点信息都没有，加上之前忘记MySQL的密码，苦苦思索一周时间了。
大致内容就是这些数据库的操作
很普通的数据库增删改查。

String sql="insert into test(name,account,password) values(?,?,?)";
    //INSERT INTO `school`.`test` (`name`, `account`, `password`) VALUES ('李四', 'uwe', '123123');
    ps=connection.prepareStatement(sql);
    ps.setObject(1,"张三");
    ps.setObject(2,"user001");
    ps.setObject(3,"1234567");
    int result=ps.executeUpdate();
    Writer writer=response.getWriter();
    writer.write("
成功修改"+result+"条记录
");
    writer.flush();
    writer.close();
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一开始在找[警告]，把警告改差不多了，发现最重要的是异常。以下是几条警告：

1. Client does not support authentication protocol requested by server;consider upgrading MySQL client
2. At least one JAR was scanned for TLDs yet contained no TLDs.
3. org.apache.tomcat.util.descriptor.web.WebXml.setVersion Unknown version string [4.0]. Default version will be used.
   接着终于明白过来其实异常才是最重要，搜到了异常的解决方式。这个是异常提示：java.sql.SQLException: Unexpected exception encountered during query.

解决方案

在IntelliJ IDEA中，创建库lib，用来放入驱动程序，我之前用的是mysql-connector-java-5.1.18-bin.jar的，换这个mysql-connector-java-5.0.8-bin.jar即可。
下载地址参考这篇文章
https://goodluckpeng.blog.csdn.net/article/details/115376310?spm=1001.2014.3001.5502
mysql-connector-java-5.0.8-bin.jar下载地址放这里：
https://mvnrepository.com/artifact/mysql/mysql-connector-java
连接之后的代码如下所示，至于还有一个警告，目前还未解决。

Connected to server
[2022-08-18 07:36:31,273] Artifact webTest:war exploded: Artifact is being deployed, please wait…
18-Aug-2022 19:36:32.908 信息 [RMI TCP Connection(5)-127.0.0.1] org.apache.jasper.servlet.TldScanner.scanJars At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
[2022-08-18 07:36:33,140] Artifact webTest:war exploded: Artifact is deployed successfully
[2022-08-18 07:36:33,141] Artifact webTest:war exploded: Deploy took 1,867 milliseconds
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