Does spring boot need persistence xml?

Does spring boot need persistence xml?

67.8 Use a traditional persistence. Spring doesn’t require the use of XML to configure the JPA provider, and Spring Boot assumes you want to take advantage of that feature. If you prefer to use persistence.

What is a persistence xml?

persistence. xml defines one or more persistence units. The jar-file element specifies JAR files that are visible to the packaged persistence unit that contain managed persistence classes, while the class element explicitly names managed persistence classes.

Where is persistence xml created?

2 Answers. Create a persistence. xml file that resides in the META-INF folder.

Is persistence XML needed?

The Java Persistence XML configuration file allows you to define a Persistence Unit configuration that you can later bootstrap using Java EE or Spring. Knowing all the persistence. xml file configuration options is very important as it allows you to address a great variety of mapping requirements.

Why do we need persistence xml?

The persistence. xml configuration file is used to configure a given JPA Persistence Unit. The Persistence Unit defines all the metadata required to bootstrap an EntityManagerFactory , like entity mappings, data source, and transaction settings, as well as JPA provider configuration properties.

What is considered optional while you define a persistence unit?

A JPA Persistence Unit is a logical grouping of user defined persistable classes (entity classes, embeddable classes and mapped superclasses) with related settings. Defining a persistence unit is optional when using ObjectDB, but required by JPA.

What is the use of Contains EntityManager methods?

The contains() method can be used to determine whether an entity instance is managed in the current persistence context. The contains method returns true: If the entity has been retrieved from the database, and has not been removed or detached.

How do I create an entitymanagerfactory in JPA without persistence?

With plain JPA, assuming that you have a PersistenceProvider implementation (e.g. Hibernate), you can use the PersistenceProvider#createContainerEntityManagerFactory (PersistenceUnitInfo info, Map map) method to bootstrap an EntityManagerFactory without needing a persistence.xml.

Why does createentitymanagerfactory() short circuit and return null?

Double-checked that the necessary JARs are included in Eclipse’s Build Path Libraries, which Google suggested may be a possible cause for a createEntityManagerFactory() call to short-circuit and return null (instead of just throwing an exception or logging a message) Might be due to a possible error whilst configuringHibernate connection?

Is it possible to get an entity manager from a context?

You can also get an EntityManager using PersistenceContext or Autowired annotation, but be aware that it will not be thread-safe. Thanks for contributing an answer to Stack Overflow!

What is the use of afterpropertiesset() in entity manager?

The call to LocalContainerEntityManagerFactoryBean.afterPropertiesSet () is essential since otherwise the factory never gets built, and then getObject () returns null and you are chasing after NullPointerException s all day long. >:- (