SpringBoot+MyBatis报错:Invalid bean definition的原因排查与解决

mvn dependency:tree | grep -i mybatis

mvn -U clean package
mvn dependency:purge-local-repository -DmanualInclude="org.mybatis.spring.boot:mybatis-spring-boot-starter"

<?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>3.1.6</version>
    <relativePath/>
  </parent>

  <groupId>com.example</groupId>
  <artifactId>demo-mybatis</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <properties>
    <java.version>17</java.version>
  </properties>

  <dependencies>
    <!-- MyBatis Spring Boot Starter （注意版本） -->
    <dependency>
      <groupId>org.mybatis.spring.boot</groupId>
      <artifactId>mybatis-spring-boot-starter</artifactId>
      <version>3.0.3</version>
    </dependency>

    <!-- Spring Web（方便启动并观察） -->
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <!-- H2 内存数据库，方便 demo -->
    <dependency>
      <groupId>com.h2database</groupId>
      <artifactId>h2</artifactId>
      <scope>runtime</scope>
    </dependency>

    <!-- 支持 JDBC -->
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-jdbc</artifactId>
    </dependency>

    <!-- 测试 -->
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
      <scope>test</scope>
    </dependency>
  </dependencies>

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

spring.datasource.url=jdbc:h2:mem:testdb;DB_CLOSE_DELAY=-1;MODE=MYSQL
spring.datasource.username=sa
spring.datasource.password=
spring.datasource.driver-class-name=org.h2.Driver

# MyBatis 配置（若使用 XML mapper，可在这里配置 locations）
mybatis.mapper-locations=classpath*:mapper/*.xml
mybatis.type-aliases-package=com.example.demo.model

CREATE TABLE users (
  id BIGINT PRIMARY KEY,
  name VARCHAR(100)
);

package com.example.demo.model;

public class User {
    private Long id;
    private String name;

    public User() {}
    public User(Long id, String name) { this.id = id; this.name = name; }

    public Long getId() { return id; }
    public void setId(Long id) { this.id = id; }

    public String getName() { return name; }
    public void setName(String name) { this.name = name; }

    @Override
    public String toString() {
        return "User{id=" + id + ", name='" + name + "'}";
    }
}

package com.example.demo.mapper;

import com.example.demo.model.User;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;

@Mapper
public interface UserMapper {

    @Insert("INSERT INTO users(id, name) VALUES(#{id}, #{name})")
    void insert(User user);

    @Select("SELECT id, name FROM users WHERE id = #{id}")
    User findById(Long id);
}

package com.example.demo;

import com.example.demo.mapper.UserMapper;
import com.example.demo.model.User;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;

@SpringBootApplication
public class DemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }

    @Bean
    CommandLineRunner runner(UserMapper userMapper) {
        return args -> {
            System.out.println("Inserting a user...");
            userMapper.insert(new User(1L, "Alice"));
            User u = userMapper.findById(1L);
            System.out.println("Found user: " + u);
        };
    }
}

mvn -U clean package
mvn spring-boot:run

Inserting a user...
Found user: User{id=1, name='Alice'}

System.out.println(org.apache.ibatis.session.SqlSessionFactory.class.getProtectionDomain().getCodeSource().getLocation());