使用SpringBoot找不到Mapper的Bean问题及解决_Java

springboot找不到mapper的bean

记一次令人抓狂的错误解决经历，先说结果：

数据库版本使用错误，没有配置pom文件中的版本号，默认使用了本地驱动中的最高6版本。

更改为5版本即可发生报错后找了很多的文档也没有符合我这个样子的，于是我就把自己的经历写下来，给和我一样犯了这个错的初学者看。

初期报错

@service
public class userservice {

    @autowired
    private deptmapper deptmapper;//此处报错为找不到mapper类型的bean

检查启动类中已经正确配置路径。

强行启动程序后

//这句话说使用数据库链接应该使用带cj那个，说明使用的驱动版本是6，但是编写的配置文件是5的配置。
loading class `com.mysql.jdbc.driver'. this is deprecated. the new driver class is `com.mysql.cj.jdbc.driver'. the driver is automatically registered via the spi and manual loading of the driver class is generally unnecessary.
//这句说的是找不到mapper的目录
property 'mapperlocations' was not specified.

如果强行调用service

就会出现如下错误：

closing non transactional sqlsession [org.apache.ibatis.session.defaults.defaultsqlsession@6b3ac131]
2021-06-05 16:43:55.847 error 32732 --- [p-nio-80-exec-1] o.a.c.c.c.[.[.[/].[dispatcherservlet] : servlet.service() for servlet [dispatcherservlet] in context with path [] threw exception [request processing failed; nested exception is org.mybatis.spring.mybatissystemexception: nested exception is org.apache.ibatis.exceptions.persistenceexception:
### error querying database. cause: org.springframework.jdbc.cannotgetjdbcconnectionexception: failed to obtain jdbc connection; nested exception is java.sql.sqlexception: the server time zone value '�й��׼ʱ��' is unrecognized or represents more than one time zone. you must configure either the server or jdbc driver (via the servertimezone configuration property) to use a more specifc time zone value if you want to utilize time zone support.
### the error may exist in top/loveeveryone/mapper/deptmapper.java (best guess)
### the error may involve top.loveeveryone.mapper.deptmapper.selectbyprimarykey
### the error occurred while executing a query
### cause: org.springframework.jdbc.cannotgetjdbcconnectionexception: failed to obtain jdbc connection; nested exception is java.sql.sqlexception: the server time zone value '�й��׼ʱ��' is unrecognized or represents more than one time zone. you must configure either the server or jdbc driver (via the servertimezone configuration property) to use a more specifc time zone value if you want to utilize time zone support.] with root cause
//说数据库时区有问题

综合检查，发现数据库驱动有问题。

在pom文件中加载mysql数据库驱动程序时没有添加驱动程序版本，默认使用最高版本导致驱动失败。

将驱动修改至5版本就好了