How to setup Spring Data JPA repositories without component scanning - spring

For performance reasons I'm switching from component scanning to explicitly declaring my beans. So basically I want to remove #EnableJpaRepositories as it scans for repositories.
My repositories are standard interfaces extending JpaRepository. How can I declare my repositories?

You can create individual repository instances by declaring a JpaRepositoryFactoryBean manually:
#Configuration
class Config {
#Bean
public JpaRepositoryFactoryBean userRepository() {
JpaRepositoryFactoryBean factory = new JpaRepositoryFactoryBean();
factory.setRepositoryInterface(UserRepository.class);
return factory;
}
}
This will cause Spring to call getObject() to obtain the repository proxy from the factory and potentially inject it into clients.
However, I'd argue that - if not configured blatantly wrong - the overhead of scanning for repositories is neglectable, esp. compared to the time initializing an EntityManagerFactory takes.

I agree with #Oliver. However, in time API of Spring Data JPA apparently has changed and in the current version (2.2.3) the snippet should look more like below:
#Configuration
class Config {
#Bean
// assuming userId is String
public JpaRepositoryFactoryBean<UserRepository, User, String> userRepository() {
JpaRepositoryFactoryBean factory = new JpaRepositoryFactoryBean(UserRepository.class);
return factory;
}
}

If you only want to configure a concrete repository bean you can directly use the factory to create it like this:
#Configuration
public class NotificationConfig {
#Bean
public NotificationRepository notificationRepository(EntityManager entityManager) {
JpaRepositoryFactory jpaRepositoryFactory=new JpaRepositoryFactory(entityManager);
return jpaRepositoryFactory.getRepository(NotificationRepository.class);
}
}

Related

Programmatic RedissonClient in Spring boot project

I am trying to implement Hibernate second level caching in a Spring boot project using Redisson.
I have followed this blog as a reference
https://pavankjadda.medium.com/implement-hibernate-2nd-level-cache-with-redis-spring-boot-and-spring-data-jpa-7cdbf5632883
Also i am trying to initialize the RedissionClient programmatically and not through declaratively /through a config file
Created a spring bean to be initialized which should create the RedissonClient instance.
#Configuration
#Lazy(value = false)
public class RedissonConfig {
#Bean
public RedissonClient redissionClient() {
Config config = new Config();
config.useSingleServer().setAddress("redis://127.0.0.1:6379");
return Redisson.create(config);
}
}
However this bean is never intialized and i get the following error while application startup.
Caused by: org.hibernate.cache.CacheException: Unable to locate Redisson configuration
at org.redisson.hibernate.RedissonRegionFactory.createRedissonClient(RedissonRegionFactory.java:107) ~[redisson-hibernate-53-3.12.1.jar:3.12.1]
at org.redisson.hibernate.RedissonRegionFactory.prepareForUse(RedissonRegionFactory.java:83) ~[redisson-hibernate-53-3.12.1.jar:3.12.1]
It seems Spring boot Hibernate still trying to load the Redisson config through a config file.
is it possible to load the Redission config in spring boot programmatically ?
Best Regards,
Saurav
I just did exactly this, here is how:
you need a custom RegionFactory that is similar to the JndiRedissonRegionFactory but gets its RedissonClient injected somehow.
an instance of this Class, fully configured, is put into the hibernate-properties map. Hibernates internal code is flexible: if the value of hibernate.cache.region.factory_class is a string it is treated as a FQDN. If it is an instance of Class<?>, it will be instantiated. If it is an Object, it will be used.
Spring offers a rather simple way to customize hibernate properties with a bean:
#AutoConfiguration(after = RedissonAutoConfiguration.class, before = JpaAutoConfiguration.class)
#ConditionalOnProperty("spring.jpa.properties.hibernate.cache.use_second_level_cache")
public class HibernateCacheAutoConfiguration {
#Bean
public HibernatePropertiesCustomizer setRegionFactory(RedissonClient redisson) {
return hibernateProperties -> hibernateProperties.put(AvailableSettings.CACHE_REGION_FACTORY, new SpringBootRedissonRegionFactory(redisson));
}
}
My RegionFactory is really simple:
#AllArgsConstructor
public class SpringBootRedissonRegionFactory extends RedissonRegionFactory {
private RedissonClient redissonClient;
#Override
protected RedissonClient createRedissonClient(Map properties) {
return redissonClient;
}
#Override
protected void releaseFromUse() {
}
}
I used the redisson-starter to get a RedissonClient, hence the reference to RedissonAutoConfiguration, but you could just create an instance by hand.
It is possible, but then you need to provide a custom implementation of RegionFactory to Hibernate, which can extends RedissonRegionFactory but uses your own client instance.

Spring Boot configuration for non-beans [duplicate]

This question already has answers here:
Injecting beans into a class outside the Spring managed context
(8 answers)
Closed 3 years ago.
Introduction
I have some business logic properties in the application.yml file.
They are loaded into the application via a #ConfigurationProperties annotated class.
How could I use these properties in a class which is not a Spring Bean? It cannot be a singleton, because many objects of it must be created during run-time.
Example
application.yml
business.foo: 2
BusinessProperties.java
#ConfigurationProperties("business")
#Getter // lombok
#Setter // lombok
public class BusinessProperties {
private int foo;
}
TypicalBean.java
#Component
public class TypicalBean {
private final BusinessProperties properties;
#Autowired
public TypicalBean(BusinessProperties properties) {
this.properties = properties;
}
#PostConstruct
public void printFoo() {
System.out.println("Foo: " + properties.getFoo()); // "Foo: 2"
}
}
NonBean.java
public class NonBean {
public void printFoo() {
System.out.println("Foo: ???"); // How to access the property?
}
}
Is there some way to create a non-singleton class, which can have access to configuration (or even other Spring beans) but otherwise works the same as a regular java class? Meaning that I can control its creation, it is collected by the garbage collector if not used anymore, etc.
You can still define the NonBean.class as a Component with Scope.Prototype
#Component
#Scope(value = BeanDefinition.SCOPE_PROTOTYPE)
public class NonBean {
#Autowired
public TypicalBean(BusinessProperties properties) {
this.properties = properties;
}
public void printFoo() {
System.out.println("Foo: " + properties.getFoo());
}
}
The trick is how you create an instance of NonBean.class. In the code where you'll be creating an instance of NonBean.class, use Spring's ObjectFactory<T>
private final ObjectFactory<NonBean> nonBeanFactory;
...
NonBean nonBean = nonBeanFactory.getObject();
The instantiated nonBean object will have been autowired.
All spring-beans creates by SpringApplicationContext. Bean - it's simple POJO-object, but created by Spring and saved in his container. If you want to get access to bean from outside of container - see this:
Getting Spring Application Context
Spring beans are really meant to be used within the application context but you might be able to achieve what you want by autowiring the properties to a static field in a Spring bean.
#Component
public class BusinessPropertiesUtils {
public static BusinessProperties INSTANCE;
#Autowired
public setBusinessProperties(BusinessProperties properties) {
this.INSTANCE = properties;
}
}
And then:
public class NonBean {
public void printFoo() {
System.out.println("Foo: " + BusinessPropertiesUtils.INSTANCE.getFoo());
}
}
PS: this is very hacky and definitely not the "Spring way".
You can configure beans with the prototype scope, which will give you a new instance of the bean every time it's requested.
From the Spring documentation:
In contrast to the other scopes, Spring does not manage the complete lifecycle of a prototype bean. The container instantiates, configures, and otherwise assembles a prototype object and hands it to the client, with no further record of that prototype instance.
...
In some respects, the Spring container’s role in regard to a prototype-scoped bean is a replacement for the Java new operator. All lifecycle management past that point must be handled by the client.
Example of how you can convert the TypicalBean class to a prototype scoped bean:
#Component
#Scope("prototype")
public class TypicalBean {
...
}
Another alternative is to manually instantiate the bean class (or any POJO) and injecting the dependencies (configuration, spring beans, etc.) through the constructor or setter methods, if you have them available or can get them from the Spring Context.
new TypicalBean(properties);

How to configure springboot to wrap DataSource during integration tests?

My goal is to have a have integration tests that ensures that there isn't too many database queries happening during lookups. (This helps us catch n+1 queries due to incorrect JPA configuration)
I know that the database connection is correct because there is no configuration problems during the test run whenever MyDataSourceWrapperConfiguration is not included in the test. However, once it is added, the circular dependency happens. (see error below) I believe #Primary is necessary in order for the JPA/JDBC code to use the correct DataSource instance.
MyDataSourceWrapper is a custom class that tracks the number of queries that have happened for a given transaction, but it delegates the real database work to the DataSource passed in via constructor.
Error:
The dependencies of some of the beans in the application context form a cycle:
org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration
┌─────┐
| databaseQueryCounterProxyDataSource defined in me.testsupport.database.MyDataSourceWrapperConfiguration
↑ ↓
| dataSource defined in org.springframework.boot.autoconfigure.jdbc.DataSourceConfiguration$Tomcat
↑ ↓
| dataSourceInitializer
└─────┘
My Configuration:
#Configuration
public class MyDataSourceWrapperConfiguration {
#Primary
#Bean
DataSource databaseQueryCounterProxyDataSource(final DataSource delegate) {
return MyDataSourceWrapper(delegate);
}
}
My Test:
#ActiveProfiles({ "it" })
#RunWith(SpringJUnit4ClassRunner.class)
#SpringApplicationConfiguration({ DatabaseConnectionConfiguration.class, DatabaseQueryCounterConfiguration.class })
#EnableAutoConfiguration
public class EngApplicationRepositoryIT {
#Rule
public MyDatabaseQueryCounter databaseQueryCounter = new MyDatabaseQueryCounter ();
#Rule
public ErrorCollector errorCollector = new ErrorCollector();
#Autowired
MyRepository repository;
#Test
public void test() {
this.repository.loadData();
this.errorCollector.checkThat(this.databaseQueryCounter.getSelectCounts(), is(lessThan(10)));
}
}
UPDATE: This original question was for springboot 1.5. The accepted answer reflects that, however, the answer from #rajadilipkolli works for springboot 2.x
In your case you will get 2 DataSource instances which is probably not what you want. Instead use BeanPostProcessor which is the component actually designed for this. See also the Spring Reference Guide.
Create and register a BeanPostProcessor which does the wrapping.
public class DataSourceWrapper implements BeanPostProcessor {
public Object postProcessBeforeInitialization(Object bean, String beanName) {
if (bean instanceof DataSource) {
return new MyDataSourceWrapper((DataSource)bean);
}
return bean;
}
public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
return bean;
}
}
Then just register that as a #Bean instead of your MyDataSourceWrapper.
Tip: Instead of rolling your own wrapping DataSource you might be interested in datasource-proxy combined with datasource-assert which has counter etc. support already (saves you maintaining your own components).
Starting from spring boot 2.0.0.M3 using BeanPostProcessor wont work.
As a work around create your own bean like below
#Bean
public DataSource customDataSource(DataSourceProperties properties) {
log.info("Inside Proxy Creation");
final HikariDataSource dataSource = (HikariDataSource) properties
.initializeDataSourceBuilder().type(HikariDataSource.class).build();
if (properties.getName() != null) {
dataSource.setPoolName(properties.getName());
}
return ProxyDataSourceBuilder.create(dataSource).countQuery().name("MyDS")
.logSlowQueryToSysOut(1, TimeUnit.MINUTES).build();
}
Another way is to use datasource-proxy version of datasource-decorator starter
Following solution works for me using Spring Boot 2.0.6.
It uses explicit binding instead of annotation #ConfigurationProperties(prefix = "spring.datasource.hikari").
#Configuration
public class DataSourceConfig {
private final Environment env;
#Autowired
public DataSourceConfig(Environment env) {
this.env = env;
}
#Primary
#Bean
public MyDataSourceWrapper primaryDataSource(DataSourceProperties properties) {
DataSource dataSource = properties.initializeDataSourceBuilder().build();
Binder binder = Binder.get(env);
binder.bind("spring.datasource.hikari", Bindable.ofInstance(dataSource).withExistingValue(dataSource));
return new MyDataSourceWrapper(dataSource);
}
}
You can actually still use BeanPostProcessor in Spring Boot 2, but it needs to return the correct type (the actual type of the declared Bean). To do this you need to create a proxy of the correct type which redirects DataSource methods to your interceptor and all the other methods to the original bean.
For example code see the Spring Boot issue and discussion at https://github.com/spring-projects/spring-boot/issues/12592.

Autowire specific implementations of persistence layer in Spring with Java based configuration

In a Spring MVC proyect I'm using Spring Data in the persistence layer so I have a bunch of repositories to access the data. I also have a layer for services so I have things like UserService or AuthorityService that use that repositories.
The problem is that I've been asked to create an interface to be able to change the implementation of the persistence layer (using DAOs for example) without have to touch a single line in the services. How can I specify in an Autowired of that interface what implementation to use? I´m using Java based config and I don't see how to inject it.
I also have a problem with the name of these new interfaces. Normally I would use a name like UserService but Spring use Service for the service layer so, What name is suitable for this type of interface?
You could mark the new implementation of the DAO as #Primary. Indicates that a bean should be given preference when multiple candidates are qualified to autowire a single-valued dependency. If exactly one 'primary' bean exists among the candidates, it will be the autowired value.
#Component
public class FooService {
private FooRepository fooRepository;
#Autowired
public FooService(FooRepository fooRepository) {
this.fooRepository = fooRepository;
}
}
#Component
public class JdbcFooRepository {
public JdbcFooService(DataSource dataSource) {
// ...
}
}
#Primary
#Component
public class HibernateFooRepository {
public HibernateFooService(SessionFactory sessionFactory) {
// ...
}
}
Because HibernateFooRepository is marked with #Primary, it will be injected preferentially over the jdbc-based variant assuming both are present as beans within the same Spring application context, which is often the case when component-scanning is applied liberally.
This annotation is semantically equivalent to the element's primary attribute in Spring XML.
I didn't completely follow your second question.

Spring Bean Extensions

I have a Spring MVC project with a generic application context xml file. This file defines the generic configuration of my applciation such as the base property file for i18n and data source to connect to the database and so on. While i define this context file i also want to define the session factory which will have base configurations such as the data source to use, the second level caching (eh-cache) and so on. But this will not contain the list of entity beans that my application would load. I want to keep the mapping of the entity beans only in separate file and load them based on need.
Is there a possibility to extend the session factory that i had defined in the base file and only add the additional entity beans? I will eventually have several spring configuration files which will load a separate set of entities. can this be achieved?
There are several posibilities.
You can use PropertyPlaceHolderConfigurer to externalize the entity list to a property file. (You can use SPEL in the property file).
You can use an abstract bean definition and use it as parent in other sessionFactory beans, then you can import thems based on a Enviroment PropertySource.
Note that Hibernate SessionFactory is inmutable after building it and SessionFactoryBean build SessionFactory in afterPropertiesSet method so the work of setting up the SessionFactoryBean that you want must be done by some BeanFactoryPostProcessor
EDIT
After reading your comment, I think that you could declare a EntityClassHolder bean and use the Autowire collections facility to get all entities in a EntityClassFactoryBean that you can inject in a single SessionFactoryBean. But i don't sure if that is that you want to do:
public class EntityClassHolder {
List<Class<?>> entityClasses;
public List<Class<?>> getEntityClasses() {
return entityClasses;
}
public void setEntityClasses(List<Class<?>> entityClasses) {
this.entityClasses = entityClasses;
}
}
public class EntityClassFactoryBean extends AbstractFactoryBean<List<Class<?>>> {
#Autowired
List<EntityClassHolder> list;
#Override
public Class<?> getObjectType() {
return List.class;
}
#Override
protected List<Class<?>> createInstance() throws Exception {
ArrayList<Class<?>> classList = new ArrayList<Class<?>>();
for (EntityClassHolder ech : list) {
classList.addAll(ech.getEntityClasses());
}
return classList;
}
}
Now, if you have several applicatonContext-xxx.xml for example, the SessionFactory will be configured with entity classes definied in EntityClassHolder beans when you load one of them.

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