How to configure sessionFactory and EntityManager in SpringBoot Application

Question

I have configured datasource in application.yml and added spring-boot-starter-data-jpa in my pom.xml. I am getting the following error while starting the server.

"Caused by: java.lang.IllegalStateException: EntityManagerFactory must not be null"

Full StackTrace:

Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [XXX.XXX.XXXDao]: Factory method 'XXXDao' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory': FactoryBean threw exception on object creation; nested exception is java.lang.IllegalStateException: EntityManagerFactory must not be null
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:189)
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588)
    ... 36 more
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory': FactoryBean threw exception on object creation; nested exception is java.lang.IllegalStateException: EntityManagerFactory must not be null
    at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.doGetObjectFromFactoryBean(FactoryBeanRegistrySupport.java:175)
    at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.getObjectFromFactoryBean(FactoryBeanRegistrySupport.java:127)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getObjectForBeanInstance(AbstractBeanFactory.java:1585)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:254)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:220)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:351)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:332)
    at org.springframework.orm.jpa.EntityManagerFactoryUtils.findEntityManagerFactory(EntityManagerFactoryUtils.java:143)
    at org.springframework.orm.jpa.EntityManagerFactoryAccessor.setBeanFactory(EntityManagerFactoryAccessor.java:137)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeAwareMethods(AbstractAutowireCapableBeanFactory.java:1597)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1565)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:331)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162)
    ... 37 more
Caused by: java.lang.IllegalStateException: EntityManagerFactory must not be null
    at org.springframework.util.Assert.state(Assert.java:392)
    at org.springframework.orm.jpa.vendor.HibernateJpaSessionFactoryBean.getObject(HibernateJpaSessionFactoryBean.java:46)
    at org.springframework.orm.jpa.vendor.HibernateJpaSessionFactoryBean.getObject(HibernateJpaSessionFactoryBean.java:41)
    at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.doGetObjectFromFactoryBean(FactoryBeanRegistrySupport.java:168)
    ... 66 more

My pom.xml,

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

    <parent>
       <groupId>org.springframework.boot</groupId>
       <artifactId>spring-boot-starter-parent</artifactId>
       <version>1.3.2.RELEASE</version>
   </parent>

 <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-orm</artifactId>
    </dependency>

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

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

    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-web</artifactId>
    </dependency>

    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
    </dependency>

    <!-- helps in serialization -->
    <dependency>
        <groupId>com.fasterxml.jackson.datatype</groupId>
        <artifactId>jackson-datatype-jdk8</artifactId>
    </dependency>

    <dependency>
        <groupId>com.fasterxml.jackson.datatype</groupId>
        <artifactId>jackson-datatype-jsr310</artifactId>
    </dependency>

My application.yml

spring:
  profiles: default
  jmx.enabled: false

---

spring:
  datasource:
    url: jdbc:mysql://localhost/databaseName
    username: root
    password: password
    driver-class-name: com.mysql.jdbc.Driver
    testOnBorrow: true
    validationQuery: SELECT 1
  jpa:
    hibernate:
      ddl-auto: validate
    properties:
      hibernate:
        current_session_context_class: org.springframework.orm.hibernate4.SpringSessionContext
example:
  scheduledJob: 
    enabled: true
  pushing:
    data:
      dir: /tmp/

Answer 1

Check if you have @SpringBootApplication or @EnableAutoConfiguration (added by @SpringBootApplication).

This will enable auto-configuration which will instantiate automatically the necessary beans for you based on the contents of your classpath. Therefore check also the classpath to see that you added all the necessary dependencies. SpringBoot helps you in adding these dependencies by providing starters which contain multiple dependencies. In your case this one - spring-boot-starter-data-jpa - which you already added

Available starters

If this still doesn't work then is something missing from the configuration (application.yml)

You can try setting one of the following keys:

spring.jpa.database= # Target database to operate on, auto-detected by default. Can be alternatively set using the "databasePlatform" property.
spring.jpa.database-platform= # Name of the target database to operate on, auto-detected by default. Can be alternatively set using the "Database" enum.

There is a reference with common settings here.

NOTE: at any time you can define your own beans which will override the ones added by auto-configuration.

Answer 2

You should add mysql dependency in pom.xml, because you are given data source driver as mysql

<dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
    </dependency>

Here example Spring boot with mysql. And spring boot one of feature is AutoConfiguration.