Spring Boot Annotation Autowired doesn't work - spring

I have a problem with the #Autowired, i show u the error and the code :
Error :
Service :
Repository :
Pom :
Main :
can you help me please :)

You exclude DataSourceAutoConfiguration.class in your #SpringBootApplication(exclude = {...} annotation.
This leads to Spring not instantiating/creating any beans for a database connectivity.
From the Spring Docs:
Auto-configuration for DataSource.
Enable auto-configuration of the Spring Application Context, attempting to guess and configure beans that you are likely to need.
In this case your DataSource:
Attempts to establish a connection with the data source that this DataSource object represents.
Since Repository annotations require a database connectivity, their beans cannot be instantiated since no DataSource beans can be found.
This leads to your issues of Repository beans not being available.

Related

Is an explicit CacheManager bean definition mandatory when using Spring Boot + Spring Cache?

From documentation Spring Boot uses ConcurrentMapCacheManager as CacheManager implementation by default if we don't define own CacheManager bean definition. But I keep getting 'No qualifying bean of type 'org.springframework.cache.CacheManager' available' error eventhough spring-boot-starter-cache and #EnableCaching is there.
Any help would be greatly appreciated.
Best regards,
SetNug
Short answer... NO.
I suspect you are having problems while (integration) testing? If so, then you probably need to declare the appropriate "test slice annotation", that is #AutoConfigureCache; see Javadoc.
To demonstrate, I created a simple example with a test class contained in this module of my SO repository. You must declare the #AutoConfigureCache annotation in configuration (see here) even if your test is a #SpringBootTest.
As Spring Boot's documentation describes, all of Spring Boot's auto-configuration (which is quite extensive) can be a bit much for testing. As such, none of Spring Boot's auto-configuration is enabled by default. Therefore, you must explicitly enable what you want, or, alternatively, you can declare that you want Spring Boot's entire auto-configuration enabled, by replacing the #AutoConfigureCache annotation declaration with Spring Boot's #EnableAutoConfiguration annotation instead.
You are correct that Spring Boot will auto-configure a "Simple" caching provider (i.e. the ConcurrentMapCacheManager, or in other words, a Spring CacheManager implementation backed by a java.util.concurent.ConcurrentHashMap; see here) when no other cache provider implementation (e.g Redis) is present or explicitly declared.
However, Spring Boot auto-configuration is only in effect when your Spring Boot application is an "application", which I have shown here.
Of course, it is also true that if your #SpringBootApplication annotated class is found (in the classpath component-scan) by your test as described, then it will also enable caching without any explicit annotations, such as, no need to explicitly declare the #AutoConfigureCache test slice annotation, even.
NOTE: In my example, I deliberately did not package the source according to the suggested structure. So, if I were to replace the #AutoConfigureCache annotation declaration in my test configuration with #Import(SpringBootDefaultCachingApplication.class) and comment out this assertion from the application class, then the test would also pass. Using the #Import annotation in this way works similarly as if the test class and application class were in the same package, or the application class were in a parent package relative to the test class.
1 last tip... you can always enable Spring Boot debugging (see Baeldung's blog) to see what auto-configuration is applied while running your application, or even while running tests.

Spring boot Jpa is not working with Spring batch and spring integration

I am working with spring batch. I needed to add some jpa repositories. So previously i was using JDBCTemplate which was working fine.
But when I started working with JPA, the spring boot application could not find the repos. Which were there.
#Autowired
ClassLevelConfigRepo clcr;
I checked these things as the best practices.
Added #EnableJpaRepositories in springBoot application class.
Added #Repostiories to the repository interfaces.
extended the interfaces with JpaRepository<Account, String>
Added #Entity to the entity classes and defined the #Table and # Column annotations properly.
But I am still getting below error.
Field clcr in com.cloudtask.batchconfig.util.LhmUtility required a bean of type 'com.cloudtask.batchconfig.repo.ClassLevelConfigRepo' that could not be found.
I tried checking all the dependencies in pom.xml it was as per recommended. And I have all the tables defined properly in data base.
I was expecting the application to return the Autowired clcr object propely.
Edit 1 : spring boot application annotations
#SpringBootApplication
#ComponentScan({"com.cloudtask"})
#EnableAsync
#IntegrationComponentScan({"com.cloudtask"})
#EnableIntegrationManagement(defaultLoggingEnabled = "true")
#EnableJpaRepositories
#EntityScan
public class imclassApplication ```
When you work with Spring Data Jpa with those basic points you should also keep track of below points.
you have added spring-boot-starter-data-jpa in your pom.xml
you have added the entity and repo package below one level of the application package.
If you the package is at same level you should specify the exact package details in the annotation. in your case it should be like :
#EnableJpaRepositories("com.cloudtask.batchconfig.repo")
#EntityScan(basePackages = {"com.cloudtask.batchconfig.entity"})
Happy programming!

How to initialize the dataSource, transactionManager configuration beans later after the server startup?

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})

Spring Boot Scanning Classes from jars issue

In my sample spring boot application, i have added a dependency of a custom jar. My sample application has a support for web and jpa.
The jar which i've created contains a Spring MVC controller. Below is the sample code
#Controller
public class StartStopDefaultMessageListenerContainerController {
#Autowired(required=false)
private Map<String, DefaultMessageListenerContainer> messageListeners;
I haven't manually created a bean instance of this controller anywhere in my code.
Problem - When i start my spring boot application by running the main class, i get an error in console that prob while autowiring DefaultMessageListenerContainer.
My question here is, even though this class StartStopDefaultMessageListenerContainerController is just present in the classpath, it's bean shouldn't be created and autowiring should not happen. But spring boot is scanning the class automatically and then it tries to autowire the fields.
Is this the normal behavior of spring and is there anyway i can avoid this?
If the StartStopDefaultMessageListenerContainerController class is part of component scanning by spring container, Yes spring tries to instantiate and resolve all dependencies.
Here your problem is #Autowired on collection. Spring docs says,
Beans that are themselves defined as a collection or map type cannot be injected through #Autowired, because type matching is not properly applicable to them. Use #Resource for such beans, referring to the specific collection or map bean by unique name.
And also Refer inject-empty-map-via-spring

Multiple DataSource beans with Spring Boot Actuator's EndpointAutoConfiguration possible?

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).

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