Spring Boot整合MyBatis Plus遇Bean注入与sqlSessionFactory缺失问题求助

场景1：未使用@MapperScan注解时 #

启动项目抛出如下异常：

Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.example.reggie.mapper.EmployeeMapper' 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:1812) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1371) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1325) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.resolveFieldValue(AutowiredAnnotationBeanPostProcessor.java:709) ~[spring-beans-6.0.3.jar:6.0.3]
    ... 34 common frames omitted

场景2：添加@MapperScan注解后 #

异常变为：

Caused by: java.lang.IllegalArgumentException: Property 'sqlSessionFactory' or 'sqlSessionTemplate' are required
    at org.springframework.util.Assert.notNull(Assert.java:204) ~[spring-core-6.0.3.jar:6.0.3]
    at org.mybatis.spring.support.SqlSessionDaoSupport.checkDaoConfig(SqlSessionDaoSupport.java:122) ~[mybatis-spring-2.0.5.jar:2.0.5]
    at org.mybatis.spring.mapper.MapperFactoryBean.checkDaoConfig(MapperFactoryBean.java:73) ~[mybatis-spring-2.0.5.jar:2.0.5]
    at org.springframework.dao.support.DaoSupport.afterPropertiesSet(DaoSupport.java:44) ~[spring-tx-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1797) ~[spring-beans-6.0.3.jar:6.0.3]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1747) ~[spring-beans-6.0.3.jar:6.0.3]
    ... 44 common frames omitted

相关代码与依赖 #

pom.xml依赖 #

<?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>3.0.1</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>reggie</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>reggie</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.12</version>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.4.2</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.9</version>
        </dependency>
        <dependency>
            <groupId>commons-lang</groupId>
            <artifactId>commons-lang</artifactId>
            <version>2.1</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.19.1</version>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>16</source>
                    <target>16</target>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

Service接口 #

package com.example.reggie.service;

import com.baomidou.mybatisplus.extension.service.IService;
import com.example.reggie.entity.Employee;

public interface EmployeeService extends IService<Employee> {
}

Service实现类 #

package com.example.reggie.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.example.reggie.entity.Employee;
import com.example.reggie.mapper.EmployeeMapper;
import com.example.reggie.service.EmployeeService;
import org.springframework.stereotype.Service;

@Service
public class EmployeeServiceImpl extends ServiceImpl<EmployeeMapper, Employee> implements EmployeeService {
}

Controller #

package com.example.reggie.controller;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.example.reggie.common.R;
import com.example.reggie.entity.Employee;
import com.example.reggie.service.EmployeeService;
import jakarta.servlet.http.HttpServletRequest;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.util.DigestUtils;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@Slf4j
@RestController
@RequestMapping("/employee")
public class EmplyeeController {
    @Autowired
    private EmployeeService employeeService;

    @PostMapping("/login")
    public R<Employee> login(HttpServletRequest request , @RequestBody Employee employee){
        String password=employee.getPassword();
        password=DigestUtils.md5DigestAsHex(password.getBytes());
        LambdaQueryWrapper<Employee> queryWrapper=new LambdaQueryWrapper<>();
        queryWrapper.eq(Employee::getUsername,employee.getUsername());
         Employee emp=employeeService.getOne(queryWrapper);

         if (emp==null){
             return R.error("Failed");
         }
         if (!emp.getPassword().equals(password)){
             return R.error("Failed");
         }
         if (emp.getStatus()==0){
             return R.error("Forbidden.");
         }
         request.getSession().setAttribute("employee",emp.getId());
        return R.success(emp);
    }
}

核心原因：版本兼容性不匹配 #

你使用的Spring Boot 3.0.1属于Spring 6.x生态，而MyBatis-Plus 3.4.2依赖的MyBatis-Spring版本是2.0.5，这个版本仅支持Spring 5.x，完全不兼容Spring 6.x，这是导致两个异常的根本原因。

第一个异常（无@MapperScan时） #

MyBatis-Plus的自动配置需要正确扫描Mapper接口生成代理Bean，但版本不兼容导致自动配置逻辑失效，Spring无法识别@Mapper注解（假设你的EmployeeMapper已添加该注解），也无法自动扫描Mapper包，因此找不到EmployeeMapper的Bean，引发依赖注入失败。

第二个异常（添加@MapperScan后） #

手动添加@MapperScan后，Spring尝试创建Mapper代理Bean，但MyBatis-Spring 2.0.5无法适配Spring 6.x的Bean生命周期管理，也无法正确获取Spring Boot自动配置的SqlSessionFactory，因此抛出sqlSessionFactory或sqlSessionTemplate缺失的异常。

解决方案 #

步骤1：升级MyBatis-Plus到兼容Spring Boot 3.x的版本 #

MyBatis-Plus从3.5.3.1开始支持Spring Boot 3.x，修改pom.xml中的MyBatis-Plus依赖：

<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.5.3.1</version>
</dependency>

步骤2：调整其他依赖版本（可选但建议） #

• Druid 1.1.9版本较老，可升级到支持Spring Boot 3.x的版本：

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.2.16</version>
</dependency>

• commons-lang 2.1版本过时，替换为commons-lang3：

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.12.0</version>
</dependency>

• fastjson 1.2.12存在安全漏洞，升级到最新稳定版：

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>2.0.42</version>
</dependency>

步骤3：确保Mapper配置正确 #

• 在EmployeeMapper接口上添加@Mapper注解，或在启动类上添加@MapperScan("com.example.reggie.mapper")（二选一即可）。
• 检查application.yml/application.properties中的数据库配置是否正确，确保Spring Boot能正常创建SqlSessionFactory。

步骤4：修正编译插件配置 #

pom.xml中maven-compiler-plugin指定的source和target为16，但配置的java.version是17，统一修改为17：

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <configuration>
        <source>17</source>
        <target>17</target>
    </configuration>
</plugin>

内容的提问来源于stack exchange，提问作者Jenkins Chen