java - 创建 bean 时出错

Question

大家晚上好，

我在这里做了一些愚蠢的事情，但似乎无法让 Spring 识别我的 bean 。我不确定我做错了什么。我的印象是我没有正确设置 bean ，但我不能确定。提前致谢。

主类:

@EnableAutoConfiguration
@ComponentScan
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class);
   }
}

我的配置:

@Configuration
public class HibernateConfig {

    @Value("${db.driver}")
    private String DB_DRIVER;

    @Value("${db.password}")
    private String DB_PASSWORD;

    @Value("${db.url}")
    private String DB_URL;

    @Value("${db.username}")
    private String DB_USERNAME;

    @Value("${hibernate.dialect}")
    private String HIBERNATE_DIALECT;

    @Value("${hibernate.show_sql}")
    private String HIBERNATE_SHOW_SQL;

    @Value("${hibernate.hbm2ddl.auto}")
    private String HIBERNATE_HBM2DDL_AUTO;

    @Value("${entitymanager.packagesToScan}")
    private String ENTITYMANAGER_PACKAGES_TO_SCAN;


    @Bean
    public DataSource dataSource(){
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClass(DB_DRIVER);
        dataSource.setJdbcUrl(DB_URL);
        dataSource.setUser(DB_USERNAME);
        dataSource.setPassword(DB_PASSWORD);
        return dataSource();
    }


    @Bean
    public LocalSessionFactoryBean sessionFactory(){
        LocalSessionFactoryBean sessionFactory = new LocalSessionFactoryBean();
        sessionFactory.setDataSource((javax.sql.DataSource) dataSource());
        sessionFactory.setPackagesToScan(ENTITYMANAGER_PACKAGES_TO_SCAN);
        Properties hibernateProperties = new Properties();
        hibernateProperties.put("hibernate.dialect", HIBERNATE_DIALECT);
        hibernateProperties.put("hibernate.show_sql", HIBERNATE_SHOW_SQL);
        hibernateProperties.put("hibernate.hbm2ddl.auto", HIBERNATE_HBM2DDL_AUTO);
        sessionFactory.setHibernateProperties(hibernateProperties);
        return sessionFactory();
    }
}

我的application.properties文件:

db.driver=com.mysql.jdbc.Driver
db.url=jdbc:mysql://localhost:3306/web_customer_tracker?useSSL=false
db.username=springstudent
db.password=springstudent

hibernate.dialect=org.hibernate.dialect.MySQL5Dialect
hibernate.show_sql=true
hibernate.hbm2ddl.auto=create
entitymanager.packagesToScan=springtutorial

我的实现:

@Repository
public class CustomerDaoImpl implements CustomerDao{

    @Autowired
    private SessionFactory sessionFactory;



    @Override
    public List<Customer> getCustomers() {


        Session session = sessionFactory.getCurrentSession();

        session.beginTransaction();

        Query<Customer> theQuery = session.createQuery("FROM CUSTOMER", Customer.class);

        List<Customer> customers = theQuery.getResultList();

        session.getTransaction().commit();

        return customers;
    }
}

我的打印跟踪:

/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/bin/java -Didea.launcher.port=7532 "-Didea.launcher.bin.path=/Applications/IntelliJ IDEA CE.app/Contents/bin" -Dfile.encoding=UTF-8 -classpath "/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/lib/charsets.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/lib/deploy.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/lib/ext/cldrdata.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/lib/ext/dnsns.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/lib/ext/jaccess.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/lib/ext/jfxrt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/lib/ext/localedata.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/lib/ext/nashorn.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/lib/ext/sunec.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/lib/ext/sunjce_provider.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/lib/ext/sunpkcs11.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/lib/ext/zipfs.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/lib/javaws.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/lib/jce.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/lib/jfr.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/lib/jfxswt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/lib/jsse.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/lib/management-agent.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/lib/plugin.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/lib/resources.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/lib/rt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/lib/ant-javafx.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/lib/dt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/lib/javafx-mx.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/lib/jconsole.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/lib/packager.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/lib/sa-jdi.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/lib/tools.jar:/Users/ronald/IdeaProjects/springtutorial/target/classes:/Users/ronald/.m2/repository/org/springframework/boot/spring-boot-starter-thymeleaf/1.5.1.RELEASE/spring-boot-starter-thymeleaf-1.5.1.RELEASE.jar:/Users/ronald/.m2/repository/org/springframework/boot/spring-boot-starter/1.5.1.RELEASE/spring-boot-starter-1.5.1.RELEASE.jar:/Users/ronald/.m2/repository/org/springframework/boot/spring-boot/1.5.1.RELEASE/spring-boot-1.5.1.RELEASE.jar:/Users/ronald/.m2/repository/org/springframework/boot/spring-boot-autoconfigure/1.5.1.RELEASE/spring-boot-autoconfigure-1.5.1.RELEASE.jar:/Users/ronald/.m2/repository/org/springframework/boot/spring-boot-starter-logging/1.5.1.RELEASE/spring-boot-starter-logging-1.5.1.RELEASE.jar:/Users/ronald/.m2/repository/ch/qos/logback/logback-classic/1.1.9/logback-classic-1.1.9.jar:/Users/ronald/.m2/repository/ch/qos/logback/logback-core/1.1.9/logback-core-1.1.9.jar:/Users/ronald/.m2/repository/org/slf4j/jul-to-slf4j/1.7.22/jul-to-slf4j-1.7.22.jar:/Users/ronald/.m2/repository/org/slf4j/log4j-over-slf4j/1.7.22/log4j-over-slf4j-1.7.22.jar:/Users/ronald/.m2/repository/org/yaml/snakeyaml/1.17/snakeyaml-1.17.jar:/Users/ronald/.m2/repository/org/thymeleaf/thymeleaf-spring4/2.1.5.RELEASE/thymeleaf-spring4-2.1.5.RELEASE.jar:/Users/ronald/.m2/repository/nz/net/ultraq/thymeleaf/thymeleaf-layout-dialect/1.4.0/thymeleaf-layout-dialect-1.4.0.jar:/Users/ronald/.m2/repository/org/codehaus/groovy/groovy/2.4.7/groovy-2.4.7.jar:/Users/ronald/.m2/repository/org/springframework/boot/spring-boot-starter-web/1.5.1.RELEASE/spring-boot-starter-web-1.5.1.RELEASE.jar:/Users/ronald/.m2/repository/org/springframework/boot/spring-boot-starter-tomcat/1.5.1.RELEASE/spring-boot-starter-tomcat-1.5.1.RELEASE.jar:/Users/ronald/.m2/repository/org/apache/tomcat/embed/tomcat-embed-core/8.5.11/tomcat-embed-core-8.5.11.jar:/Users/ronald/.m2/repository/org/apache/tomcat/embed/tomcat-embed-el/8.5.11/tomcat-embed-el-8.5.11.jar:/Users/ronald/.m2/repository/org/apache/tomcat/embed/tomcat-embed-websocket/8.5.11/tomcat-embed-websocket-8.5.11.jar:/Users/ronald/.m2/repository/org/hibernate/hibernate-validator/5.3.4.Final/hibernate-validator-5.3.4.Final.jar:/Users/ronald/.m2/repository/javax/validation/validation-api/1.1.0.Final/validation-api-1.1.0.Final.jar:/Users/ronald/.m2/repository/com/fasterxml/jackson/core/jackson-databind/2.8.6/jackson-databind-2.8.6.jar:/Users/ronald/.m2/repository/com/fasterxml/jackson/core/jackson-annotations/2.8.0/jackson-annotations-2.8.0.jar:/Users/ronald/.m2/repository/com/fasterxml/jackson/core/jackson-core/2.8.6/jackson-core-2.8.6.jar:/Users/ronald/.m2/repository/org/springframework/spring-web/4.3.6.RELEASE/spring-web-4.3.6.RELEASE.jar:/Users/ronald/.m2/repository/org/springframework/spring-aop/4.3.6.RELEASE/spring-aop-4.3.6.RELEASE.jar:/Users/ronald/.m2/repository/org/springframework/spring-context/4.3.6.RELEASE/spring-context-4.3.6.RELEASE.jar:/Users/ronald/.m2/repository/org/springframework/spring-webmvc/4.3.6.RELEASE/spring-webmvc-4.3.6.RELEASE.jar:/Users/ronald/.m2/repository/org/springframework/spring-expression/4.3.6.RELEASE/spring-expression-4.3.6.RELEASE.jar:/Users/ronald/.m2/repository/org/springframework/spring-core/4.3.6.RELEASE/spring-core-4.3.6.RELEASE.jar:/Users/ronald/.m2/repository/org/springframework/spring-orm/4.3.7.RELEASE/spring-orm-4.3.7.RELEASE.jar:/Users/ronald/.m2/repository/org/springframework/spring-beans/4.3.6.RELEASE/spring-beans-4.3.6.RELEASE.jar:/Users/ronald/.m2/repository/org/springframework/spring-jdbc/4.3.6.RELEASE/spring-jdbc-4.3.6.RELEASE.jar:/Users/ronald/.m2/repository/org/springframework/spring-tx/4.3.6.RELEASE/spring-tx-4.3.6.RELEASE.jar:/Users/ronald/.m2/repository/org/hibernate/hibernate-core/5.2.9.Final/hibernate-core-5.2.9.Final.jar:/Users/ronald/.m2/repository/org/jboss/logging/jboss-logging/3.3.0.Final/jboss-logging-3.3.0.Final.jar:/Users/ronald/.m2/repository/org/hibernate/javax/persistence/hibernate-jpa-2.1-api/1.0.0.Final/hibernate-jpa-2.1-api-1.0.0.Final.jar:/Users/ronald/.m2/repository/org/javassist/javassist/3.21.0-GA/javassist-3.21.0-GA.jar:/Users/ronald/.m2/repository/antlr/antlr/2.7.7/antlr-2.7.7.jar:/Users/ronald/.m2/repository/org/jboss/spec/javax/transaction/jboss-transaction-api_1.2_spec/1.0.1.Final/jboss-transaction-api_1.2_spec-1.0.1.Final.jar:/Users/ronald/.m2/repository/org/jboss/jandex/2.0.3.Final/jandex-2.0.3.Final.jar:/Users/ronald/.m2/repository/com/fasterxml/classmate/1.3.3/classmate-1.3.3.jar:/Users/ronald/.m2/repository/dom4j/dom4j/1.6.1/dom4j-1.6.1.jar:/Users/ronald/.m2/repository/org/hibernate/common/hibernate-commons-annotations/5.0.1.Final/hibernate-commons-annotations-5.0.1.Final.jar:/Users/ronald/.m2/repository/mysql/mysql-connector-java/5.1.40/mysql-connector-java-5.1.40.jar:/Users/ronald/.m2/repository/c3p0/c3p0/0.9.1.2/c3p0-0.9.1.2.jar:/Users/ronald/.m2/repository/commons-logging/commons-logging/1.1.1/commons-logging-1.1.1.jar:/Users/ronald/.m2/repository/org/springframework/boot/spring-boot-starter-data-jpa/1.5.1.RELEASE/spring-boot-starter-data-jpa-1.5.1.RELEASE.jar:/Users/ronald/.m2/repository/org/springframework/boot/spring-boot-starter-aop/1.5.1.RELEASE/spring-boot-starter-aop-1.5.1.RELEASE.jar:/Users/ronald/.m2/repository/org/aspectj/aspectjweaver/1.8.9/aspectjweaver-1.8.9.jar:/Users/ronald/.m2/repository/org/springframework/boot/spring-boot-starter-jdbc/1.5.1.RELEASE/spring-boot-starter-jdbc-1.5.1.RELEASE.jar:/Users/ronald/.m2/repository/org/apache/tomcat/tomcat-jdbc/8.5.11/tomcat-jdbc-8.5.11.jar:/Users/ronald/.m2/repository/org/apache/tomcat/tomcat-juli/8.5.11/tomcat-juli-8.5.11.jar:/Users/ronald/.m2/repository/org/hibernate/hibernate-entitymanager/5.0.11.Final/hibernate-entitymanager-5.0.11.Final.jar:/Users/ronald/.m2/repository/javax/transaction/javax.transaction-api/1.2/javax.transaction-api-1.2.jar:/Users/ronald/.m2/repository/org/springframework/data/spring-data-jpa/1.11.0.RELEASE/spring-data-jpa-1.11.0.RELEASE.jar:/Users/ronald/.m2/repository/org/springframework/data/spring-data-commons/1.13.0.RELEASE/spring-data-commons-1.13.0.RELEASE.jar:/Users/ronald/.m2/repository/org/slf4j/jcl-over-slf4j/1.7.22/jcl-over-slf4j-1.7.22.jar:/Users/ronald/.m2/repository/org/springframework/spring-aspects/4.3.6.RELEASE/spring-aspects-4.3.6.RELEASE.jar:/Users/ronald/.m2/repository/org/thymeleaf/thymeleaf-spring3/3.0.3.RELEASE/thymeleaf-spring3-3.0.3.RELEASE.jar:/Users/ronald/.m2/repository/org/thymeleaf/thymeleaf/2.1.5.RELEASE/thymeleaf-2.1.5.RELEASE.jar:/Users/ronald/.m2/repository/org/unbescape/unbescape/1.1.0.RELEASE/unbescape-1.1.0.RELEASE.jar:/Users/ronald/.m2/repository/org/slf4j/slf4j-api/1.7.22/slf4j-api-1.7.22.jar:/Users/ronald/mysql-connector-java-5.1.41/mysql-connector-java-5.1.41-bin.jar:/Applications/IntelliJ IDEA CE.app/Contents/lib/idea_rt.jar" com.intellij.rt.execution.application.AppMain com.luv2code.springtutorial.Application

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v1.5.1.RELEASE)

2017-04-11 19:55:25.895  INFO 826 --- [           main] com.luv2code.springtutorial.Application  : Starting Application on Ronalds-MacBook-Pro.local with PID 826 (/Users/ronald/IdeaProjects/springtutorial/target/classes started by ronald in /Users/ronald/IdeaProjects/springtutorial)
2017-04-11 19:55:25.905  INFO 826 --- [           main] com.luv2code.springtutorial.Application  : No active profile set, falling back to default profiles: default
2017-04-11 19:55:26.429  INFO 826 --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@64d2d351: startup date [Tue Apr 11 19:55:26 EDT 2017]; root of context hierarchy
2017-04-11 19:55:28.179  INFO 826 --- [           main] o.s.b.f.s.DefaultListableBeanFactory     : Overriding bean definition for bean 'dataSource' with a different definition: replacing [Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=hibernateConfig; factoryMethodName=dataSource; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [com/luv2code/springtutorial/config/HibernateConfig.class]] with [Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=org.springframework.boot.autoconfigure.jdbc.DataSourceConfiguration$Tomcat; factoryMethodName=dataSource; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Tomcat.class]]
2017-04-11 19:55:28.946  INFO 826 --- [           main] trationDelegate$BeanPostProcessorChecker : Bean 'org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration' of type [class org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
2017-04-11 19:55:29.096  INFO 826 --- [           main] trationDelegate$BeanPostProcessorChecker : Bean 'validator' of type [class org.springframework.validation.beanvalidation.LocalValidatorFactoryBean] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
2017-04-11 19:55:29.200  INFO 826 --- [           main] trationDelegate$BeanPostProcessorChecker : Bean 'org.springframework.transaction.annotation.ProxyTransactionManagementConfiguration' of type [class org.springframework.transaction.annotation.ProxyTransactionManagementConfiguration$$EnhancerBySpringCGLIB$$bdd5f28b] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
2017-04-11 19:55:29.967  INFO 826 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http)
2017-04-11 19:55:30.147  INFO 826 --- [           main] o.apache.catalina.core.StandardService   : Starting service Tomcat
2017-04-11 19:55:30.152  INFO 826 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.5.11
2017-04-11 19:55:30.548  INFO 826 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2017-04-11 19:55:30.549  INFO 826 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 4128 ms
2017-04-11 19:55:30.811  INFO 826 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean  : Mapping servlet: 'dispatcherServlet' to [/]
2017-04-11 19:55:30.840  INFO 826 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'characterEncodingFilter' to: [/*]
2017-04-11 19:55:30.840  INFO 826 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2017-04-11 19:55:30.841  INFO 826 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2017-04-11 19:55:30.841  INFO 826 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'requestContextFilter' to: [/*]
2017-04-11 19:55:31.078  WARN 826 --- [           main] ationConfigEmbeddedWebApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'customerController': Unsatisfied dependency expressed through field 'customerDao'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'customerDaoImpl': Unsatisfied dependency expressed through field 'sessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in class path resource [com/luv2code/springtutorial/config/HibernateConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.orm.hibernate4.LocalSessionFactoryBean]: Factory method 'sessionFactory' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Tomcat.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.apache.tomcat.jdbc.pool.DataSource]: Factory method 'dataSource' threw exception; nested exception is org.springframework.boot.autoconfigure.jdbc.DataSourceProperties$DataSourceBeanCreationException: Cannot determine embedded database driver class for database type NONE. If you want an embedded database please put a supported one on the classpath. If you have database settings to be loaded from a particular profile you may need to active it (no profiles are currently active).
2017-04-11 19:55:31.091  INFO 826 --- [           main] utoConfigurationReportLoggingInitializer : 

Error starting ApplicationContext. To display the auto-configuration report re-run your application with 'debug' enabled.
2017-04-11 19:55:31.099 ERROR 826 --- [           main] o.s.b.d.LoggingFailureAnalysisReporter   : 

***************************
APPLICATION FAILED TO START
***************************

Description:

Cannot determine embedded database driver class for database type NONE

Action:

If you want an embedded database please put a supported one on the classpath. If you have database settings to be loaded from a particular profile you may need to active it (no profiles are currently active).


Process finished with exit code 130 (interrupted by signal 2: SIGINT)

Answer 1

Spring boot 的整体思想是减少配置并使用约定。您正在尝试使用 Spring Boot 并尝试配置数据源并自行 hibernate ，但这是无用的。只需将所需的启动器添加到您的 pom 或 gradle 构建文件中即可。仅添加 mysql 驱动程序并org.springframework.boot:spring-boot-starter-jpa 进入您的类路径。

将以下条目添加到 application.properties/yml 文件中。

spring.datasource.url=jdbc:mysql://localhost:3306/web_customer_tracker?useSSL=false
spring.datasource.username=springstudent
spring.datasource.password=springstudent
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.jpa.hibernate.ddl-auto=create-drop
spring.jpa.hibernate.show-sql=true
spring.jpa.hibernate.dialect=org.hibernate.dialect.MySQL5Dialect

Spring 启动自动配置会选择数据源属性并为您创建数据源。此外，JPA 配置将使用 hibernate 完成，并且将为您创建 EntityManager/SessionFactory，您可以在需要时 Autowiring 。您可以放弃 @Configuration 类，然后直接在代码中 Autowiring 数据源/ session 工厂。

确保您的实体位于使用类 @EnableAutoConfiguration 的子包中，以便它可以选择它们。还考虑使用 @SpringBootApplication 作为 @EnableAutoConfiguration 和 @ComponentScan 的便捷注释替代方案

如果你真的想自己配置数据源，那么排除 Spring boot 自动配置。

@EnableAutoConfiguration(exclude = {DataSourceAutoConfiguration.class, HibernateJpaAutoConfiguration.class})