在springboot和myabtisplus版本没有冲突的情况下，MybatisPlusAutoConfiguration配置类没有生效，查看该类发现存在生效条件，即：

1.必须存在数据源的Bean对象

2.必须存在SqlSessionFactory和SqlSessionFactoryBean类（这个一般不可能出问题） 

 

 所以一定是数据源没注入，原因是我把数据源自动配置类排除掉了：

修改后的正确代码如下： 

pom.xml

    <properties>
        <java.version>1.8</java.version>
        <mysql-connector.version>8.0.32</mysql-connector.version>
        <lombok.version>1.18.20</lombok.version>
        <dbcp.version>1.3</dbcp.version>
        <druid.version>1.2.11</druid.version>
        <springboot.version>2.3.12.RELEASE</springboot.version>
        <mybatisplus.version>3.4.1</mybatisplus.version>
        <knife4j.version>2.0.8</knife4j.version>

        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-logging</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <!--spring-jdbc-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <!--mybatis-plus-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>${mybatisplus.version}</version>
        </dependency>
        <!--pagehelper-->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper-spring-boot-starter</artifactId>
            <version>1.3.0</version>
            <exclusions>
                <exclusion>
                    <groupId>org.mybatis</groupId>
                    <artifactId>mybatis</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.mybatis</groupId>
                    <artifactId>mybatis-spring</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>com.github.jsqlparser</groupId>
                    <artifactId>jsqlparser</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <!-- 代码自动生成 -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-generator</artifactId>
            <version>${mybatisplus.version}</version>
            <exclusions>
                <exclusion>
                    <groupId>com.github.jsqlparser</groupId>
                    <artifactId>jsqlparser</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>com.github.jsqlparser</groupId>
            <artifactId>jsqlparser</artifactId>
            <version>3.1</version>
        </dependency>
        <!--druid连接池-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>${druid.version}</version>
        </dependency>
        <!--log4j-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-log4j2</artifactId>
        </dependency>
        <dependency>
            <scope>provided</scope>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>${lombok.version}</version>
        </dependency>
        <dependency>
            <groupId>commons-dbcp</groupId>
            <artifactId>commons-dbcp</artifactId>
            <version>${dbcp.version}</version>
        </dependency>

        <dependency>
            <scope>provided</scope>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>${mysql-connector.version}</version>
        </dependency>
        <dependency>
            <scope>provided</scope>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>${lombok.version}</version>
        </dependency>
        <dependency>
            <groupId>commons-dbcp</groupId>
            <artifactId>commons-dbcp</artifactId>
            <version>${dbcp.version}</version>
        </dependency>

        <dependency>
            <scope>provided</scope>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>${mysql-connector.version}</version>
        </dependency>

启动类

@SpringBootApplication
@EnableCaching
@ServletComponentScan
@EnableAutoConfiguration(exclude = {DataSourceAutoConfiguration.class})
@ComponentScan("com.xxx")
@MapperScan("com.xxx.**.mapper")
public class WindsApplication {
    public static void main(String[] args) {
        SpringApplication.run(WindsApplication.class,args);
    }
}