This version is still in development and is not considered stable yet. For the latest stable version, please use Spring Data Neo4j 7.3.5! |
Creating Repository Instances
This section covers how to create instances and bean definitions for the defined repository interfaces.
Java Configuration
Use the store-specific @EnableNeo4jRepositories
annotation on a Java configuration class to define a configuration for repository activation.
For an introduction to Java-based configuration of the Spring container, see JavaConfig in the Spring reference documentation.
A sample configuration to enable Spring Data repositories resembles the following:
@Configuration
@EnableJpaRepositories("com.acme.repositories")
class ApplicationConfiguration {
@Bean
EntityManagerFactory entityManagerFactory() {
// …
}
}
The preceding example uses the JPA-specific annotation, which you would change according to the store module you actually use. The same applies to the definition of the EntityManagerFactory bean. See the sections covering the store-specific configuration.
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XML Configuration
Each Spring Data module includes a repositories
element that lets you define a base package that Spring scans for you, as shown in the following example:
<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns:beans="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://www.springframework.org/schema/data/jpa"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/data/jpa
https://www.springframework.org/schema/data/jpa/spring-jpa.xsd">
<jpa:repositories base-package="com.acme.repositories" />
</beans:beans>
In the preceding example, Spring is instructed to scan com.acme.repositories
and all its sub-packages for interfaces extending Repository
or one of its sub-interfaces.
For each interface found, the infrastructure registers the persistence technology-specific FactoryBean
to create the appropriate proxies that handle invocations of the query methods.
Each bean is registered under a bean name that is derived from the interface name, so an interface of UserRepository
would be registered under userRepository
.
Bean names for nested repository interfaces are prefixed with their enclosing type name.
The base package attribute allows wildcards so that you can define a pattern of scanned packages.
Using Filters
By default, the infrastructure picks up every interface that extends the persistence technology-specific Repository
sub-interface located under the configured base package and creates a bean instance for it.
However, you might want more fine-grained control over which interfaces have bean instances created for them.
To do so, use filter elements inside the repository declaration.
The semantics are exactly equivalent to the elements in Spring’s component filters.
For details, see the Spring reference documentation for these elements.
For example, to exclude certain interfaces from instantiation as repository beans, you could use the following configuration:
-
Java
-
XML
@Configuration
@EnableNeo4jRepositories(basePackages = "com.acme.repositories",
includeFilters = { @Filter(type = FilterType.REGEX, pattern = ".*SomeRepository") },
excludeFilters = { @Filter(type = FilterType.REGEX, pattern = ".*SomeOtherRepository") })
class ApplicationConfiguration {
@Bean
EntityManagerFactory entityManagerFactory() {
// …
}
}
<repositories base-package="com.acme.repositories">
<context:include-filter type="regex" expression=".*SomeRepository" />
<context:exclude-filter type="regex" expression=".*SomeOtherRepository" />
</repositories>
The preceding example includes all interfaces ending with SomeRepository
and excludes those ending with SomeOtherRepository
from being instantiated.
Standalone Usage
You can also use the repository infrastructure outside of a Spring container — for example, in CDI environments.You still need some Spring libraries in your classpath, but, generally, you can set up repositories programmatically as well.The Spring Data modules that provide repository support ship with a persistence technology-specific RepositoryFactory
that you can use, as follows:
RepositoryFactorySupport factory = … // Instantiate factory here
UserRepository repository = factory.getRepository(UserRepository.class);