springboot+mybatis報錯找不到實體類的問題

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springboot+mybatis報錯找不到實體類

找不到實體類的錯誤可能有很多，接下來列舉幾個地方

啟動類位置不對，啟動類應該在你的service和dao 的上一層，因為Spring是從啟動類所在目錄的同級目錄開始掃描的，當然你也可以放在其他地方，但需要配置，具體配置可以參考網上的其他文章！

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mapper.xml文件的路勁配置是否正確，classpath指的是resources目錄，如果不在resources目錄下，註意正確配置路勁。

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mapper接口類是否添加@Repository註解，表示這是數據訪問組件。如果采用註解的形式使用mybatis需要加@Mapper

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service層是否添加@Service註解,將bean註入到上下文中.

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啟動類是否添加@MapperScan(掃描mapper)，@EntityScan(掃描實體類），如果啟動類不在上面(1)所說的位置，則需要自己添加@ComRepositor註解，自定義掃描的路徑從中找出標識瞭需要裝配的類自動裝配到spring的bean容器中。

springboot+mybatis 找不到實體類問題

No qualifying bean of type‘com.wj.bfsh.mapper.SysUserMapper‘ available

報錯如下

2021-02-18 09:45:58,826 – Starting BfshApplication on DESKTOP-AAPVN38 with PID 10552 (F:\IdeaIu\work_place\bfsh\target\classes started by AoDexiusi in F:\IdeaIu\work_place\bfsh)
2021-02-18 09:45:58,828 – Running with Spring Boot v2.3.7.RELEASE, Spring v5.2.12.RELEASE
2021-02-18 09:45:58,829 – No active profile set, falling back to default profiles: default
2021-02-18 09:45:58,868 – Devtools property defaults active! Set 'spring.devtools.add-properties' to 'false' to disable
2021-02-18 09:45:58,868 – For additional web related logging consider setting the 'logging.level.web' property to 'DEBUG'
2021-02-18 09:45:59,438 – No MyBatis mapper was found in '[com.wj.bfsh.mapper.*]' package. Please check your configuration.
2021-02-18 09:45:59,809 – Tomcat initialized with port(s): 8888 (http)
2021-02-18 09:45:59,816 – Starting service [Tomcat]
2021-02-18 09:45:59,816 – Starting Servlet engine: [Apache Tomcat/9.0.41]
2021-02-18 09:45:59,925 – Initializing Spring embedded WebApplicationContext
2021-02-18 09:45:59,925 – Root WebApplicationContext: initialization completed in 1057 ms
2021-02-18 09:45:59,969 – Exception encountered during context initialization – cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sysUserController': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sysUserServiceImpl': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.wj.bfsh.mapper.SysUserMapper' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@javax.annotation.Resource(shareable=true, lookup=, name=, description=, authenticationType=CONTAINER, type=class java.lang.Object, mappedName=)}
2021-02-18 09:45:59,971 – Stopping service [Tomcat]
2021-02-18 09:45:59,978 – The web application [bfsh] appears to have started a thread named [Abandoned connection cleanup thread] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
 java.lang.Object.wait(Native Method)
 java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:143)
 com.mysql.jdbc.AbandonedConnectionCleanupThread.run(AbandonedConnectionCleanupThread.java:40)
2021-02-18 09:45:59,986 – 

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2021-02-18 09:46:00,105 – 

***************************
APPLICATION FAILED TO START
***************************

Description:

A component required a bean of type 'com.wj.bfsh.mapper.SysUserMapper' that could not be found.

Action:

Consider defining a bean of type 'com.wj.bfsh.mapper.SysUserMapper' in your configuration.

我的啟動類：

@SpringBootApplication
@MapperScan(basePackages = "com.wj.bfsh.mapper.*")
public class BfshApplication {
    public static void main(String[] args) {
        SpringApplication.run(BfshApplication.class, args);
    }
}

項目結構：

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問題出現在

@MapperScan(basePackages = “com.wj.bfsh.mapper.*”)

修改為：

@MapperScan(basePackages = “com.wj.bfsh.mapper”)

其實就是dao層掃描的位置不對。

以上為個人經驗，希望能給大傢一個參考，也希望大傢多多支持WalkonNet。

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