springboot整合mybatis-plus和pagehelper插件报错，

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);}
}