【mybatis-plus问题集锦系列】在mybatisplus中无法autowired的原因排查及解决

mybatisplus简化了我们做数据操作，大大提升了我们的开发速度，但是今天在做测试的时候，突然报了这么个错误，排查好久才找到解决方案，特此记录下

问题复现

这里的测试方法报错，通过不了测试

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'com.itheima.Springboot02MpApplicationTests': Unsatisfied dependency expressed through field 'userDao': No qualifying bean of type 'com.itheima.dao.UserDao' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}

	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:788)
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:768)
	at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:145)
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:509)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1439)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireBeanProperties(AbstractAutowireCapableBeanFactory.java:398)
	at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:143)
	at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:98)
	at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:260)
	at org.springframework.test.context.junit.jupiter.SpringExtension.postProcessTestInstance(SpringExtension.java:163)
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
	at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:179)
	at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1625)
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509)
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499)
	at java.base/java.util.stream.StreamSpliterators$WrappingSpliterator.forEachRemaining(StreamSpliterators.java:310)
	at java.base/java.util.stream.Streams$ConcatSpliterator.forEachRemaining(Streams.java:735)
	at java.base/java.util.stream.Streams$ConcatSpliterator.forEachRemaining(Streams.java:734)
	at java.base/java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:762)
	at java.base/java.util.Optional.orElseGet(Optional.java:364)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.itheima.dao.UserDao' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1894)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1411)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1358)
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:785)
	... 21 more

有问题的依赖

<parent>
   <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>3.3.7</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.4.2</version>
</dependency>

个人猜测肯定是版本的问题，不兼容。因为只要引入这个左边就报错，注销就正常测试。所以一直在试着修改版本号，还是无法解决。

解决方案

参考官网: mybatisplus官网

springboot3中整个坐标都变了，所以写法都大不一样，彻底的大坑，修改坐标引入pom.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.3.7</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.itheima</groupId>
    <artifactId>springboot_02_mp</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springboot_02_mp</name>
    <description>springboot_02_mp</description>
    <url/>
    <licenses>
        <license/>
    </licenses>
    <developers>
        <developer/>
    </developers>
    <scm>
        <connection/>
        <developerConnection/>
        <tag/>
        <url/>
    </scm>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
<!--        <dependency>-->
<!--            <groupId>com.baomidou</groupId>-->
<!--            <artifactId>mybatis-plus-boot-starter</artifactId>-->
<!--            <version>3.4.2</version>-->
<!--        </dependency>-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-spring-boot3-starter</artifactId>
            <version>3.5.9</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.16</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

刷新pom文件，然后再次运行就可以正常运行了。测试文件正常

控制台正常

这样，我们就解决这个报错问题了。