I am aware of initializing the dataSource and transactionManager beans. But we have a requirement where at the time of server startup, database may not be available so we don't want to initialize these beans at the time of server startup otherwise we used to see the exception in logs.
We are using #Configuration, #EnableJpaRepositories annotation for managing the persistence context.
Can we achieve such kind of configuration in Spring where we want to initialize the dataSource bean at the time of first API request i.e. lazily?
If you are using Spring boot, can exclude as below
#EnableAutoConfiguration(exclude = {DataSourceAutoConfiguration.class, DataSourceTransactionManagerAutoConfiguration.class})
Related
TL;DR
When using MyBatis with Spring boot, is following step possible?
Create Datasource, SqlSessionFactory, SqlTransactionManager beans without mapperscan
Deploy 1 as library
import 2, create Mapper with beans declared in 1 with #Mapper annotation
Question
(First of all, apologize my poor english)
I'm creating mybatis datasource autoconfiguration library for my spring boot project.
Datasource will used at some applications, and they would have different mapper.
If mappers are already defined, creating DataSource, SqlSessionFactory and SqlTransactionManager beans with #MapperScan can bind Mapper and those beans.
But when case like this; DataSource, SqlSessionFactory, SqlTransactionManager beans declared,
and Mappers will created later, is possible binding specific beans with #Mapper annotation?
Those beans are default currently, so project would works.
But if another datasource added without mapper scan,
application initialization failed due to duplicate bean definition.
For some reasons, i prefer these done with mapper annotation(not mapper xml)
If any another advice for this design, looking forward to answer.
Thank you.
I used spring security. And, I have made below settings for my spring boot project.
spring:
main:
lazy-initialization: true
So, All spring beans are lazy initialization.
In this situation, I want to early inject only the authentication manager.
What should I do?
I think you can use #Lazy(value = false) in your #Component that uses it. As per docs:
If this annotation is not present on a #Component or #Bean definition, eager initialization will occur. If present and set to true, the #Bean or #Component will not be initialized until referenced by another bean or explicitly retrieved from the enclosing BeanFactory. If present and set to false, the bean will be instantiated on startup by bean factories that perform eager initialization of singletons.
I have created a spring mvc based application but I didn't use this #Configuration annotation. What is the purpose of using #Configuration annotation? By using this, what are we communicating to springMVC container?
Assuming your application is using xml configuration rather than AnnotationConfig so it is not loaded to ApplicationContext at all.
#Configuration is used when ApplicationContext has been initialized and bean registration.
#Configuration annotation is a core Spring annotation, and not Spring MVC. It is a core entry point to configuring Spring-based application using Java config instead of XML config.
Please, use Spring Documentation more often because it is a place where you will find answers to most of your questions. Like this one:
Indicates that a class declares one or more Bean #Bean methods and may
be processed by the Spring container to generate bean definitions and
service requests for those beans at runtime
I have a spring-boot application that uses several DataSource beans and would still like to use the EndpointAutoConfiguration from spring-boot-actuator that is loaded as part of using the #EnableAutoConfiguration annotation. This doesn't seem possible as there is a DataSource bean injected into EndpointAutoConfiguration to setup the HealthEndpoint bean. Due to the multiple instances of DataSource that exist in my application, a NoUniqueBeanDefinitionException is thrown upon application startup unless I exclude EndpointAutoConfiguration but then I must setup all the other endpoints manually (/env, /metrics, etc).
Is there a better way to do this?
You could mark one of your DataSources as #Primary or you could provide your own HealthIndicator (it's not the endpoint that wants your DataSource but that bean, which is designed to be overridden by just adding one of your own).
I have a problem with transaction in spring, because in my project datasources are created in runtime from side files and according to documentation:
I should inject to TransactionManager dataSource and made it visible for annotation #Transactional using <tx:annotation-driven transaction-manager="txManager"/>.
So my question is how can I do it when I want to use annotation?
First of all how are you creating the datasources at runtime.
if directly as Datasource=new datasource... I will suges use BeanDefinitionBuilder in Spring 3.2 to Create the Datasourcebean and then register it via BeanDefinitionRegistry.
and then get the bean from Spring context and it will be considered using the transaction.