Hibernate 6 With Spring Boot
Chloe Sarnoff
Spring Boot is built on the top of the spring and contains all the features of spring. And is becoming a favorite of developers these days because of its rapid production-ready environment which enables the developers to directly focus on the logic instead of struggling with the configuration and setup. Spring Boot is a microservice-based framework and making a production-ready application in it takes very little time.
JPA is an abstraction that is used to map the java object with the database. It contains different structures of the methods that are used for manipulating the table record and also provides the SQL queries for specific operations.
Extract the zip file. Now open a suitable IDE and then go to File -> New -> Project from existing sources -> Springbootapp and select pom.xml. Click on import changes on prompt and wait for the project to sync.
For database operation we have to configure the Spring application with the database also it is required to add configuration of the database before executing the Spring project. If we try to run the Spring application that contains JPA dependency with adding the configuration of the database it causes an error. Running the project without database configuration:
We start with a coverage of Hibernate 5 in a Spring environment,using it to demonstrate the approach that Spring takes towards integrating OR mappers.This section covers many issues in detail and shows different variations of DAOimplementations and transaction demarcation. Most of these patterns can be directlytranslated to all other supported ORM tools. The later sections in this chapter thencover the other ORM technologies and show brief examples.
Hibernate ORM 6.x is only supported as a JPA provider (HibernateJpaVendorAdapter).Plain SessionFactory setup with the orm.hibernate5 package is not supported anymore.We recommend Hibernate ORM 6.1/6.2 with JPA-style setup for new development projects.
To avoid tying application objects to hard-coded resource lookups, you can defineresources (such as a JDBC DataSource or a Hibernate SessionFactory) as beans in theSpring container. Application objects that need to access resources receive referencesto such predefined instances through bean references, as illustrated in the DAOdefinition in the next section.
Both LocalSessionFactoryBean and LocalSessionFactoryBuilder support backgroundbootstrapping, with Hibernate initialization running in parallel to the applicationbootstrap thread on a given bootstrap executor (such as a SimpleAsyncTaskExecutor).On LocalSessionFactoryBean, this is available through the bootstrapExecutorproperty. On the programmatic LocalSessionFactoryBuilder, there is an overloadedbuildSessionFactory method that takes a bootstrap executor argument.
As of Spring Framework 5.1, such a native Hibernate setup can also expose a JPAEntityManagerFactory for standard JPA interaction next to native Hibernate access.See Native Hibernate Setup for JPA for details.
The main advantage of this DAO style is that it depends on Hibernate API only. No importof any Spring class is required. This is appealing from a non-invasivenessperspective and may feel more natural to Hibernate developers.
You can annotate the service layer with @Transactional annotations and instruct theSpring container to find these annotations and provide transactional semantics forthese annotated methods. The following example shows how to do so:
You can demarcate transactions in a higher level of the application, on top oflower-level data access services that span any number of operations. Nor do restrictionsexist on the implementation of the surrounding business service. It needs only a SpringPlatformTransactionManager. Again, the latter can come from anywhere, but preferablyas a bean reference through a setTransactionManager(..) method. Also, theproductDAO should be set by a setProductDao(..) method. The following pair of snippets showa transaction manager and a business service definition in a Spring application contextand an example for a business method implementation:
For distributed transactions across multiple Hibernate session factories, you can combineJtaTransactionManager as a transaction strategy with multipleLocalSessionFactoryBean definitions. Each DAO then gets one specific SessionFactoryreference passed into its corresponding bean property. If all underlying JDBC datasources are transactional container ones, a business service can demarcate transactionsacross any number of DAOs and any number of session factories without special regard, aslong as it uses JtaTransactionManager as the strategy.
Both HibernateTransactionManager and JtaTransactionManager allow for properJVM-level cache handling with Hibernate, without container-specific transaction managerlookup or a JCA connector (if you do not use EJB to initiate transactions).
HibernateTransactionManager can export the Hibernate JDBC Connection to plain JDBCaccess code for a specific DataSource. This ability allows for high-leveltransaction demarcation with mixed Hibernate and JDBC data access completely withoutJTA, provided you access only one database. HibernateTransactionManager automaticallyexposes the Hibernate transaction as a JDBC transaction if you have set up the passed-inSessionFactory with a DataSource through the dataSource property of theLocalSessionFactoryBean class. Alternatively, you can specify explicitly theDataSource for which the transactions are supposed to be exposed through thedataSource property of the HibernateTransactionManager class.
For JTA-style lazy retrieval of actual resource connections, Spring provides acorresponding DataSource proxy class for the target connection pool: seeLazyConnectionDataSourceProxy.This is particularly useful for Hibernate read-only transactions which can oftenbe processed from a local cache rather than hitting the database.
In some JTA environments with very strict XADataSource implementations (currentlysome WebLogic Server and WebSphere versions), when Hibernate is configured withoutregard to the JTA transaction manager for that environment, spurious warnings orexceptions can show up in the application server log. These warnings or exceptionsindicate that the connection being accessed is no longer valid or JDBC access is nolonger valid, possibly because the transaction is no longer active. As an example,here is an actual exception from WebLogic:
Pass your Spring JtaTransactionManager bean to your Hibernate setup. The easiestway is a bean reference into the jtaTransactionManager property for yourLocalSessionFactoryBean bean (see Hibernate Transaction Setup).Spring then makes the corresponding JTA strategies available to Hibernate.
In some environments, this Connection.close() call then triggers the warning orerror, as the application server no longer considers the Connection to be usable,because the transaction has already been committed.
The move to Spring Boot 3 will upgrade a number of dependencies and might require work on your end.You can review dependency management for 2.7.x with dependency management for 3.0.x to asses how your project is affected.
You may also use dependencies that are not managed by Spring Boot (e.g. Spring Cloud).As your project defines an explicit version for those, you need first to identify the compatible version before upgrading.
Spring Boot 3.0 uses Spring Security 6.0.The Spring Security team have released Spring Security 5.8 to simplify upgrading to Spring Security 6.0.Before upgrading to Spring Boot 3.0, consider upgrading your Spring Boot 2.7 application to Spring Security 5.8.The Spring Security team have produced a migration guide that will help you to do so. From there, you can follow the 5.8 to 6.0 migration guide when upgrading to Spring Boot 3.0.
Whenever Spring Boot depends on a Jakarta EE specification, Spring Boot 3.0 has upgraded to the version that is included in Jakarta EE 10.For example, Spring Boot 3.0 uses the Servlet 6.0 and JPA 3.1 specifications.
@ConstructorBinding is no longer needed at the type level on @ConfigurationProperties classes and should be removed.When a class or record has multiple constructors, it may still be used on a constructor to indicate which one should be used for property binding.
If you were relying on autowiring of a dependency into the constructor of a @ConfigurationProperties class, you must now annotate it with @Autowired to prevent it being identified as a target for property binding.
Spring Boot 2.7 introduced a new META-INF/spring/org.springframework.boot.autoconfigure.AutoConfiguration.imports file for registering auto-configurations, while maintaining backwards compatibility with registration in spring.factories.With this release, support for registering auto-configurations in spring.factories using the org.springframework.boot.autoconfigure.EnableAutoConfiguration key has been removed in favor of the imports file. Other entries in spring.factories under other keys are unaffected.
Libraries targeting both Spring Boot 3.x and 2.x can safely list their auto-configuration classes in both spring.factories and AutoConfiguration.imports. Spring Boot 2.7, which supports both locations, will de-duplicate any entries that are listed twice.
As of Spring Framework 6.0, the trailing slash matching configuration option has been deprecated and its default value set to false.This means that previously, the following controller would match both "GET /some/greeting" and "GET /some/greeting/":
Previously, the server.max-http-header-size was treated inconsistently across the four supported embedded web servers.When using Jetty, Netty, or Undertow it would configure the max HTTP request header size.When using Tomcat it would configure the max HTTP request and response header sizes.
To address this inconsistency, server.max-http-header-size has been deprecated and a replacement, server.max-http-request-header-size, has been introduced.Both properties now only apply to the request header size, irrespective of the underlying web server.
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