没有名为“Transaction Manager”的bean可用

Question

当我试图使用spring代码创建关系时，我得到了事务管理器错误。我正在我的项目中使用Mysql和Neo4j数据库。我尝试了不同的解决方法，但都解决不了。

noSuchBeanDefinitionException：没有名为“Transaction Manager”的bean可用：没有为限定符“Transaction Manager”找到匹配的PlatformTransactionManager bean-既没有限定符匹配，也没有bean名称匹配！

pom.xml文件如下所示

 <?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 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.10.RELEASE</version>
    </parent>

    <dependencies>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>1.5.10.RELEASE</version>
        </dependency>

        <!-- For Neo4J Graph Database -->
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-neo4j</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

        <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.9-rc</version>
        </dependency>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-thymeleaf</artifactId>
    <version>1.5.10.RELEASE</version>
</dependency>
 <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
    </dependency>

    </dependencies>

    <properties>
        <java.version>1.8</java.version>
        <thymeleaf.version>3.0.2.RELEASE</thymeleaf.version>
        <thymeleaf-layout-dialect.version>2.1.1</thymeleaf-layout-dialect.version>
    </properties>
</project>

    @SpringBootApplication
    @EnableTransactionManagement
    @EntityScan("projectone.entities")
    public class Application {

        public static void main(String[] args) {
            //For Starting application
            ApplicationContext applicationContext=SpringApplication.run(Application.class, args);

        }
    }

@Configuration
@EnableJpaRepositories(basePackages = {"projectone.mysql"},
        entityManagerFactoryRef = "dbEntityManager",
        transactionManagerRef = "dbTransactionManager")
@EnableTransactionManagement
public class DatabaseConfiguration {

     @Autowired


 private Environment env;
        @Bean
        @Primary
        public LocalContainerEntityManagerFactoryBean dbEntityManager() {
            LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
            em.setDataSource(dbDatasource());
            em.setPackagesToScan(new String[]{"projectone.mysql"});
            em.setPersistenceUnitName("dbEntityManager");
            HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
            em.setJpaVendorAdapter(vendorAdapter);

            HashMap<String, Object> properties = new HashMap<>();

            properties.put("hibernate.dialect",env.getProperty("hibernate.dialect"));
            properties.put("hibernate.show-sql",env.getProperty("jdbc.show-sql"));


            em.setJpaPropertyMap(properties);
            return em;
        }
        @Primary
        @Bean
        public DataSource dbDatasource() {
            DriverManagerDataSource dataSource
                    = new DriverManagerDataSource();
            dataSource.setDriverClassName(
                    env.getProperty("spring.datasource.driverClassName"));
            dataSource.setUrl(env.getProperty("spring.datasource.url"));
            dataSource.setUsername(env.getProperty("spring.datasource.username"));
            dataSource.setPassword(env.getProperty("spring.datasource.password"));
            return dataSource;
        }
        @Primary
        @Bean
        public PlatformTransactionManager dbTransactionManager() {
            JpaTransactionManager transactionManager
                    = new JpaTransactionManager();
            transactionManager.setEntityManagerFactory(
                    dbEntityManager().getObject());
            return transactionManager;
        }

}

如果我只使用@SpringBootApplication注释，那么我将得到以下异常：它正在抛出

    org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'mappingController': Unsatisfied dependency expressed through field 'branchService'; 
nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'branchServiceImplementaion': Unsatisfied dependency expressed through field 'branchRepository'; 

nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'branchRepository': Unsatisfied dependency expressed through method 'setSession' parameter 0; 

nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.data.neo4j.transaction.SharedSessionCreator#0': Cannot resolve reference to bean 'sessionFactory' while setting constructor argument; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in class path resource [org/springframework/boot/autoconfigure/data/neo4j/Neo4jDataAutoConfiguration.class]: Bean instantiation via factory method failed;

 nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.neo4j.ogm.session.SessionFactory]: Factory method 'sessionFactory' threw exception; nested exception is NullPointerException

Answer 1

终于发现了错误：

 @Bean
        public PlatformTransactionManager dbTransactionManager() {
            JpaTransactionManager transactionManager
                    = new JpaTransactionManager();
            transactionManager.setEntityManagerFactory(
                    dbEntityManager().getObject());
            return transactionManager;
        }

本节错误导致了上述问题。将@bean更改为@bean(Name=“TransactionManager”）就解决了这个问题。