前言
在练习一个springboot项目时，在执行时出现了下面的报错信息，找了好久都不知道怎么回事，因此，记录下整个过程，从而鞭策如菜鸡一样的自己。我的问题是打包问题（删除pom打包方式就可以了）
目 录
前言
1、报错问题
2、解决过程
3、解决方式
4、总结
1、报错问题
Caused by: : Error creating bean with name 'sqlSessionFactory' defined in class path resource [com/baomidou/mybatisplus/autoconfigure/]: Bean instantiation via factory method failed; nested exception is : Failed to instantiate []: Factory method 'sqlSessionFactory' threw exception; nested exception is : Error: GlobalConfigUtils setMetaData Fail ! Cause:: Error: Get proxy targetObject exception ! Cause:: Error creating bean with name '' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$]: Bean instantiation via factory method failed; nested exception is : Failed to instantiate []: Factory method 'dataSource' threw exception; nested exception is $DataSourceBeanCreationException: Failed to determine a suitable driver class
2、解决过程
整体的错误为：
: Error creating bean with name 'eduTeacherController': Unsatisfied dependency expressed through field 'teacherService'; nested exception is : Error creating bean with name 'eduTeacherServiceImpl': Unsatisfied dependency expressed through field 'baseMapper'; nested exception is : Error creating bean with name 'eduTeacherMapper' defined in file [D:\ajavaproject\guli-parent\service\service-edu\target\classes\com\atguigu\eduservice\mapper\]: Unsatisfied dependency expressed through bean property 'sqlSessionFactory'; nested exception is : Error creating bean with name 'sqlSessionFactory' defined in class path resource [com/baomidou/mybatisplus/autoconfigure/]: Bean instantiation via factory method failed; nested exception is : Failed to instantiate []: Factory method 'sqlSessionFactory' threw exception; nested exception is : Error: GlobalConfigUtils setMetaData Fail ! Cause:: Error: Get proxy targetObject exception ! Cause:: Error creating bean with name '' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$]: Bean instantiation via factory method failed; nested exception is : Failed to instantiate []: Factory method 'dataSource' threw exception; nested exception is $DataSourceBeanCreationException: Failed to determine a suitable driver class
at $(:639) ~[spring-beans-5.2.:5.2.]
at (:116) ~[spring-beans-5.2.:5.2.]
at (:397) ~[spring-beans-5.2.:5.2.]
at (:1429) ~[spring-beans-5.2.:5.2.]
at (:594) ~[spring-beans-5.2.:5.2.]
at (:517) ~[spring-beans-5.2.:5.2.]
at $doGetBean$0(:323) ~[spring-beans-5.2.:5.2.]
at (:222) ~[spring-beans-5.2.:5.2.]
at (:321) ~[spring-beans-5.2.:5.2.]
at (:202) ~[spring-beans-5.2.:5.2.]
at (:879) ~[spring-beans-5.2.:5.2.]
at (:878) ~[spring-context-5.2.:5.2.]
at (:550) ~[spring-context-5.2.:5.2.]
at (:141) ~[spring-boot-2.2.:2.2.]
at (:747) [spring-boot-2.2.:2.2.]
at (:397) [spring-boot-2.2.:2.2.]
at (:315) [spring-boot-2.2.:2.2.]
at (:1226) [spring-boot-2.2.:2.2.]
at (:1215) [spring-boot-2.2.:2.2.]
at (:19) [classes/:na]
Caused by: : Error creating bean with name 'eduTeacherServiceImpl': Unsatisfied dependency expressed through field 'baseMapper'; nested exception is : Error creating bean with name 'eduTeacherMapper' defined in file [D:\ajavaproject\guli-parent\service\service-edu\target\classes\com\atguigu\eduservice\mapper\]: Unsatisfied dependency expressed through bean property 'sqlSessionFactory'; nested exception is : Error creating bean with name 'sqlSessionFactory' defined in class path resource [com/baomidou/mybatisplus/autoconfigure/]: Bean instantiation via factory method failed; nested exception is : Failed to instantiate []: Factory method 'sqlSessionFactory' threw exception; nested exception is : Error: GlobalConfigUtils setMetaData Fail ! Cause:: Error: Get proxy targetObject exception ! Cause:: Error creating bean with name '' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$]: Bean instantiation via factory method failed; nested exception is : Failed to instantiate []: Factory method 'dataSource' threw exception; nested exception is $DataSourceBeanCreationException: Failed to determine a suitable driver class
at $(:639) ~[spring-beans-5.2.:5.2.]
at (:116) ~[spring-beans-5.2.:5.2.]
at (:397) ~[spring-beans-5.2.:5.2.]
at (:1429) ~[spring-beans-5.2.:5.2.]
at (:594) ~[spring-beans-5.2.:5.2.]
at (:517) ~[spring-beans-5.2.:5.2.]
at $doGetBean$0(:323) ~[spring-beans-5.2.:5.2.]
at (:222) ~[spring-beans-5.2.:5.2.]
at (:321) ~[spring-beans-5.2.:5.2.]
at (:202) ~[spring-beans-5.2.:5.2.]
at (:276) ~[spring-beans-5.2.:5.2.]
at (:1287) ~[spring-beans-5.2.:5.2.]
at (:1207) ~[spring-beans-5.2.:5.2.]
at $(:636) ~[spring-beans-5.2.:5.2.]
... 19 common frames omitted
Caused by: : Error creating bean with name 'eduTeacherMapper' defined in file [D:\ajavaproject\guli-parent\service\service-edu\target\classes\com\atguigu\eduservice\mapper\]: Unsatisfied dependency expressed through bean property 'sqlSessionFactory'; nested exception is : Error creating bean with name 'sqlSessionFactory' defined in class path resource [com/baomidou/mybatisplus/autoconfigure/]: Bean instantiation via factory method failed; nested exception is : Failed to instantiate []: Factory method 'sqlSessionFactory' threw exception; nested exception is : Error: GlobalConfigUtils setMetaData Fail ! Cause:: Error: Get proxy targetObject exception ! Cause:: Error creating bean with name '' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$]: Bean instantiation via factory method failed; nested exception is : Failed to instantiate []: Factory method 'dataSource' threw exception; nested exception is $DataSourceBeanCreationException: Failed to determine a suitable driver class
at (:1533) ~[spring-beans-5.2.:5.2.]
at (:1413) ~[spring-beans-5.2.:5.2.]
at (:594) ~[spring-beans-5.2.:5.2.]
at (:517) ~[spring-beans-5.2.:5.2.]
at $doGetBean$0(:323) ~[spring-beans-5.2.:5.2.]
at (:222) ~[spring-beans-5.2.:5.2.]
at (:321) ~[spring-beans-5.2.:5.2.]
at (:202) ~[spring-beans-5.2.:5.2.]
at (:276) ~[spring-beans-5.2.:5.2.]
at (:1287) ~[spring-beans-5.2.:5.2.]
at (:1207) ~[spring-beans-5.2.:5.2.]
at $(:636) ~[spring-beans-5.2.:5.2.]
... 32 common frames omitted
Caused by: : Error creating bean with name 'sqlSessionFactory' defined in class path resource [com/baomidou/mybatisplus/autoconfigure/]: Bean instantiation via factory method failed; nested exception is : Failed to instantiate []: Factory method 'sqlSessionFactory' threw exception; nested exception is : Error: GlobalConfigUtils setMetaData Fail ! Cause:: Error: Get proxy targetObject exception ! Cause:: Error creating bean with name '' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$]: Bean instantiation via factory method failed; nested exception is : Failed to instantiate []: Factory method 'dataSource' threw exception; nested exception is $DataSourceBeanCreationException: Failed to determine a suitable driver class
at (:645) ~[spring-beans-5.2.:5.2.]
at (:625) ~[spring-beans-5.2.:5.2.]
at (:1338) ~[spring-beans-5.2.:5.2.]
at (:1177) ~[spring-beans-5.2.:5.2.]
at (:557) ~[spring-beans-5.2.:5.2.]
at (:517) ~[spring-beans-5.2.:5.2.]
at $doGetBean$0(:323) ~[spring-beans-5.2.:5.2.]
at (:222) ~[spring-beans-5.2.:5.2.]
at (:321) ~[spring-beans-5.2.:5.2.]
at (:202) ~[spring-beans-5.2.:5.2.]
at (:276) ~[spring-beans-5.2.:5.2.]
at (:1287) ~[spring-beans-5.2.:5.2.]
at (:1207) ~[spring-beans-5.2.:5.2.]
at (:1518) ~[spring-beans-5.2.:5.2.]
... 43 common frames omitted
Caused by: : Failed to instantiate []: Factory method 'sqlSessionFactory' threw exception; nested exception is : Error: GlobalConfigUtils setMetaData Fail ! Cause:: Error: Get proxy targetObject exception ! Cause:: Error creating bean with name '' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$]: Bean instantiation via factory method failed; nested exception is : Failed to instantiate []: Factory method 'dataSource' threw exception; nested exception is $DataSourceBeanCreationException: Failed to determine a suitable driver class
at (:185) ~[spring-beans-5.2.:5.2.]
at (:640) ~[spring-beans-5.2.:5.2.]
... 56 common frames omitted
Caused by: : Error: GlobalConfigUtils setMetaData Fail ! Cause:: Error: Get proxy targetObject exception ! Cause:: Error creating bean with name '' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$]: Bean instantiation via factory method failed; nested exception is : Failed to instantiate []: Factory method 'dataSource' threw exception; nested exception is $DataSourceBeanCreationException: Failed to determine a suitable driver class
at (:51) ~[mybatis-plus-core-3.0.:na]
at (:602) ~[mybatis-plus-extension-3.0.:na]
at (:386) ~[mybatis-plus-extension-3.0.:na]
at (:683) ~[mybatis-plus-extension-3.0.:na]
at (:165) ~[mybatis-plus-boot-starter-3.0.:na]
at $$EnhancerBySpringCGLIB$$$sqlSessionFactory$0(<generated>) ~[mybatis-plus-boot-starter-3.0.:na]
at $$EnhancerBySpringCGLIB$$c469479b$$FastClassBySpringCGLIB$$(<generated>) ~[mybatis-plus-boot-starter-3.0.:na]
at (:244) ~[spring-core-5.2.:5.2.]
at $(:363) ~[spring-context-5.2.:5.2.]
at $$EnhancerBySpringCGLIB$$(<generated>) ~[mybatis-plus-boot-starter-3.0.:na]
at .invoke0(Native Method) ~[na:1.8.0_341]
at (:62) ~[na:1.8.0_341]
at (:43) ~[na:1.8.0_341]
at (:498) ~[na:1.8.0_341]
at (:154) ~[spring-beans-5.2.:5.2.]
... 57 common frames omitted
Process finished with exit code 1首先，看到上面的错误，我以为是数据源的问题，因此我去配置文件里查看相关的配置，仔细对比了DataSource等配置（搜博客有人说他是由于数据库url写错了，因此我认真对比），经过仔细对比，没有问题。又忙活了一阵子，有人提出在springboot启动类上添加注解@EnableAutoConfiguration，添加上后仍然执行报错。
@EnableAutoConfiguration(exclude = {})于是又在网上巴拉巴拉一阵搜，得到一个关键信息，发现是编译后target出了问题，执行程序后，在target文件里未生成文件，因此报错数据源有问题。于是在pom文件中配置以下的配置，运行程序，依然执行错误，查看target文件依然没有application配置文件。
<build>
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.yml</include>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>false</filtering>
</resource>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.yml</include>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>false</filtering>
</resource>
</resources>
</build>于是，我根据以往的编译文件，将此项目的xml文件以及文件复制到target文件的相应目录下，然后执行程序，结果程序正常运行了，那么知道具体的什么原因了（刚开始是猜的）。
紧接着搜索是什么原因导致编译后target中没有生成文件，搜索了一大堆，都没有解决，下班了都没解决。
3、解决方式
早上来了，脑袋一热，想到会不会是打包方式的问题，然后简单一搜发现，最小子项目中的pom文件中打包方式为pom类型，删除pom打包方式，使用mvn clear清除target，然后执行程序，程序执行正常了，此时生成的target中也包含了xml文件和application配置文件。
于是又去网上搜索学习了maven 的三种打包方式：pom、jar、war，在pom文件中不写的情况下，默认为jar打包方式。
- pom是maven依赖文件
- jar是java普通项目打包文件
- war是javaweb项目打包文件
具体应用
- pom打包方式可以作为其他项目的maven依赖，构建maven项目时可用在父级工程或者聚合工程中，用来做jar包的版本控制；
- jar包通常是开发时需要应用的类，当需要某些功能时就导入相应的jar包,在构建maven时作为子类；
- war包用来发布服务，打成war包后部署到服务器访问。
4、总结
以上就是我遇到的问题，以及整个过程，最后通过更改打包方式解决了以上问题，可能你的问题与我遇到的问题不同，但是，我相信只要你饱含信心，多思考多搜索多询问，那么你一定能解决，加油，码代码的少年！
学习之所以会想睡觉，是因为那是梦开始的地方。
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------不写代码不会凸的小刘