where Spring framework transactional implementation? - spring

How can i find the implementations of transactional annotion of springframework?
I only found the code below:
This is decompiled.class file.
package org.springframework.transaction.annotation;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Inherited;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import org.springframework.core.annotation.AliasFor;
#Target({ElementType.TYPE, ElementType.METHOD})
#Retention(RetentionPolicy.RUNTIME)
#Inherited
#Documented
public #interface Transactional {
#AliasFor("transactionManager")
String value() default "";
#AliasFor("value")
String transactionManager() default "";
Propagation propagation() default Propagation.REQUIRED;
Isolation isolation() default Isolation.DEFAULT;
int timeout() default -1;
boolean readOnly() default false;
Class<? extends Throwable>[] rollbackFor() default {};
String[] rollbackForClassName() default {};
Class<? extends Throwable>[] noRollbackFor() default {};
String[] noRollbackForClassName() default {};
}
Some description but not see how exactly it implemented:
You can place the #Transactional annotation before an interface definition, a method on an interface, a class definition, or a public method on a class. However, the mere presence of the #Transactional annotation is not enough to activate the transactional behavior. The #Transactional annotation is simply metadata that can be consumed by some runtime infrastructure that is #Transactional -aware and that can use the metadata to configure the appropriate beans with transactional behavior. In the preceding example, the <tx:annotation-driven/> element switches on the transactional behavior.

Behind the scenes reflection is player, You can see the implementation of TransactionAnnotationParser.java interface (Strategy interface for parsing known transaction annotation types. AnnotationTransactionAttributeSource delegates to such parsers for supporting specific annotation types such as Spring's own Transactional, JTA 1.2's Transactional or EJB3's TransactionAttribute.),
Based on implementation SpringTransactionAnnotationParser is one of strategy implementation for parsing Spring's Transactional annotation its parse the transaction.
If you need to deep dive into this then you need to go through with spring-tx module

Related

Dependency injection does not work in RestClientBuilderListener

I followed the rest client guide in Quarkus web site. It works fine. But when registering a global provider using the ServiceLoader pattern, as described in the specification, the CDI beans injection did not work, they are all null. I downloaded the example and simply added the following classes:
package org.acme.rest.client;
import org.eclipse.microprofile.rest.client.ext.ResponseExceptionMapper;
import javax.enterprise.context.ApplicationScoped;
import javax.ws.rs.core.Response;
#ApplicationScoped
public class MyExceptionMapper implements ResponseExceptionMapper<Exception> {
#Override
public Exception toThrowable (Response response) {
return new Exception();
}
}
package org.acme.rest.client;
import org.eclipse.microprofile.rest.client.RestClientBuilder;
import org.eclipse.microprofile.rest.client.spi.RestClientBuilderListener;
import javax.enterprise.context.ApplicationScoped;
import javax.inject.Inject;
#ApplicationScoped
public class MyListener implements RestClientBuilderListener {
#Inject MyExceptionMapper myExceptionMapper;
#Override
public void onNewBuilder (RestClientBuilder builder) {
builder.register(myExceptionMapper);
}
}
I also added the file META-INF/services/org.eclipse.microprofile.rest.client.spi.RestClientBuilderListener with the content org.acme.rest.client.MyListener. The MyListener onNewBuilder method is invoked, but the injected provider MyExceptionMapper is null. How to register a global provider in Quarkus client?
Implementation of RestClientBuilderListener are not CDI beans - they are just objects that are created via the normal Java ServiceLoader mechanism when RestClientBuilder is being used.
So if you want to obtain CDI beans when onNewBuilder is called, you can do something like:
CDI.current().select(MyExceptionMapper.class).get()
Furthermore, you need to annotate MyExceptionMapper with #Provider, not #ApplicationScoped.

Element Cannot be Resolved as Variable error in a custom annotation for method interception

New to Spring and AOP programming. Working on a spring AOP tutorial to write aspects that intercept method calls. Would like to enable time logging.
As instructed by the tutorial I created a custom annotation for logging and an aspect to define what should be done when this annotation is called.
The code below is the TrackTime annotation:
package com.in28minutes.springboot.tutorial.basics.example.aop;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
#Target(ElementType.METHOD)
#Retention(RetentionPolicy.RUNTIME)
public #interface TrackTime {}
However Eclipse is displaying the errors –
“Element Cannot be Resolved as Variable/Retention Cannot be resolved to a variable”
I then created an aspect called MethodExecutionCalculationAspect with the ‘TrackTime’ annotation.
#Around("#annotation(com.in28minutes.springboot.tutorial.
basics.example.aop.TrackTime)")
MethodExecutionCalculationAspect
package com.in28minutes.springboot.tutorial.basics.example.aop;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.Configuration;
#Aspect
#Configuration
public class MethodExecutionCalculationAspect {
private Logger logger = LoggerFactory.getLogger(this.getClass());
#Around("#annotation
(com.in28minutes.springboot.tutorial.basics.example.aop.TrackTime)")
public void around(ProceedingJoinPoint joinPoint) throws Throwable {
long startTime = System.currentTimeMillis();
joinPoint.proceed();
long timeTaken = System.currentTimeMillis() - startTime;
logger.info("Time Taken by {} is {}", joinPoint, timeTaken);
}
}
#Around uses an around advice. It intercepts the method call and uses joinPoint.proceed() to execute the method.
#annotation(com.in28minutes.springboot.tutorial.basics.example.aop.TrackTime) is the pointcut to define interception based on an annotation — #annotation
followed by the complete type name of the annotation.
Once I correct the annotation and the advice, I’m hoping to use the annotation on methods for time tracking. as shown below:
#Service
public class Business1 {
#TrackTime
public String calculateSomething(){
Any help would be appreciated.
Information about the project is as follows:
SpringBootTutorialBasicsAplication.java:
The Spring Boot application class generated with Spring Initializer. This class acts as the launching point for the application.
• pom.xml: Contains all the dependencies needed to build this project using Spring Boot Starter AOP.
• Business1.java, Business2.java, Dao1.java, Dao2.java: Business classes are dependent on DAO classes.
• We would write aspects to intercept calls to these business and DAO classes.
• AfterAopAspect.java: Implements a few After advices.
• UserAccessAspect.java: Implements a Before advice to do an access check.
• BusinessAopSpringBootTest.java: The unit test that invokes the business methods.
• Maven 3.0+ is your build tool
• Eclipse.
• JDK 1.8+
Your TrackTime is missing imports for RetentionPolicy and Target.
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

Spring boot cannot find beans

i have a Spring Boot project which has some external packages i need to import as Beans in the main application.
So i have my main application in com.package.app package and some classes (among which some repositories) in com.package.commons package.
In order to take these beans i have my main class annotated as follows:
#SpringBootApplication
#ComponentScan({ "com.package.commons" ,"com.package.app"})
#EnableScheduling
#EnableAsync
public class EmanagerApplication extends SpringBootServletInitializer{
public static void main(String[] args) {
SpringApplication.run(EmanagerApplication.class, args);
}
}
But when i launch the application it may occur (not always but very ofter) that the start up fails with these kind of error:
Description:
Field repository in com.package.commons.service.BrandService required a bean of type 'com.package.commons.persistence.repository.BrandRepository' that could not be found.
Action:
Consider defining a bean of type 'com.package.commons.persistence.repository.BrandRepository' in your configuration.
My BrandRepository is annotated with #Repository and the service class with #Service
The really strange thing is that if i keep launching the app at the end it stars... but there is no reason for it...
If you're using JPA, you'll also need the #EnableJpaRepositories annotation.
Also consider to use #EnableTransactionManagement to enable declarative transaction handling.
E.g. use something like the following in the same package or a parent package where you have your JPA entities and JPA repositories (untested):
import java.util.HashMap;
import java.util.Map;
import javax.sql.DataSource;
import org.springframework.beans.factory.ObjectProvider;
import org.springframework.boot.autoconfigure.orm.jpa.JpaBaseConfiguration;
import org.springframework.boot.autoconfigure.orm.jpa.JpaProperties;
import org.springframework.boot.autoconfigure.transaction.TransactionManagerCustomizers;
import org.springframework.orm.jpa.vendor.AbstractJpaVendorAdapter;
import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
import org.springframework.transaction.jta.JtaTransactionManager;
#Configuration
#EntityScan
#EnableJpaRepositories
#EnableTransactionManagement
public class HibernateConfig extends JpaBaseConfiguration {
public HibernateConfig(DataSource dataSource, JpaProperties properties, ObjectProvider<JtaTransactionManager> jtaTransactionManager,
ObjectProvider<TransactionManagerCustomizers> transactionManagerCustomizers) {
super(dataSource, properties, jtaTransactionManager, transactionManagerCustomizers);
}
#Override
protected AbstractJpaVendorAdapter createJpaVendorAdapter() {
return new HibernateJpaVendorAdapter();
}
#Override
protected Map<String, Object> getVendorProperties() {
return new HashMap<>();
}
}
And don't forget to annotate your #Service classes also with #Transactional.
If you confirm that the Application which with the startup method of this application is good, and confirm the #ComponentScan is good also. And the configuration file yaml or properties of JPA also good.
How about trying extends JPA Repository like this:
public class xxxResponsitory extends JpaRepository<T, E>{
...
}
Cause JpaRepository has already annotated with #Repository annotation, T means the type of Primary Key, I always use Integer or Long, autoboxing type. E means the main type of this repository.
Make an example:
Now we have an Entity type named User, the Primary key type of User is Long, I would write the repository like this:
public class UserRepository extends JpaRepository<Long, User>{
...
}
Don't need annotated anything, then, In the service class, #Autowried UserRepository, everything is good to run. But make sure the things that I talk at the start of my answer.
Hope this can help you.

Are Spring JpaRepository custom-implementations automatically transactional?

everything is in the title...
I have a repository extending JpaRepository<User, Long> with additional customized methods, following the pattern described in http://docs.spring.io/spring-data/jpa/docs/1.4.3.RELEASE/reference/html/jpa.repositories.html
The Spring documentation says: CRUD methods on repository instances are transactional by default. For reading operations the transaction configuration readOnly flag is set to true, all others are configured with a plain #Transactional.
Does this applies to the custom-methods? Are there transactional?
Advanced: Where could I find the answer by myself? (i.e. which class of Spring framework is responsible for generating the dynamic-proxy and decorating the calls?)
Thank you in advance!
1) Same as Ralphs answer. They have to be annotated with #Transaction or handled by you explicitly
2) There is no "responsible" class for extending/decorating the Spring repository interfaces. YOU are the one responsible for extending them.
I'm going to add an example of a custom method that executes a custom query.
PersonRepository
public interface PostRepository extends CrudRepository<Post, Long>{
List<Post> getPostsOlderThanDate(Date date);
}
PersonRepositoryImpl
import org.springframework.data.jpa.repository.support.SimpleJpaRepository;
import javax.persistence.EntityManager;
import javax.persistence.TypedQuery;
import java.util.Date;
import java.util.List;
public class PostRepositoryImpl extends SimpleJpaRepository<Post, Long> implements PostRepository {
private EntityManager entityManager;
public PostRepositoryImpl(EntityManager em) {
super(Post.class, em);
this.entityManager = em;
}
#Transactional
#Override
public List<Post> getPostsOlderThanDate(Date date) {
String query = ""; //create query
TypedQuery<Post> typedQuery = entityManager.createQuery(query, Post.class);
return typedQuery.getResultList();
}
}
You then create your EntityManagerFactory bean (which you build with a Hibernate persistance provider, or however you set it up, it's up to you), and inject it into the constructor of the PersonRepositoryImpl bean.
<bean id="personRepository" class="com.package.PersonRepositoryImpl">
<constructor-arg ref="entityManagerFactory" />
</bean>
These would be the steps to provide some custom queries into your database.
NOTE: if you need help setting up your EntityManager just leave a comment addressed to me and I'll give you the spring config and dependencies.

Spring AOP annotation based pointcuts for ElementType.TYPE?

I have a service implementation carrying a class-wide #Transactional annotation. I also have an aspect that uses the #Around advice to retry failed transactions. I'm now trying (for type-safety reasons) to make the pointcut definition annotation based:
#Around("#annotation(TransactionRetryable)")
TransactionRetryable.java:
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.lang.annotation.ElementType;
#Retention(RetentionPolicy.RUNTIME)
#Target({ElementType.METHOD, ElementType.TYPE})
public #interface TransactionRetryable {
}
Service layer:
#Transactional
public class ... {
#Override
#TransactionRetryable
public String forceError() {
throw new RuntimeException(someNastyMessage);
}
In that form, it only applies to method, not whole classes. However, the #Transactional annotation propagates from class level to each method. Is there a way to avoid putting the #TransactionRetryable annotation above each method and simply once above the class like the #Transactional annotation? Desired form:
#Transactional
#TransactionRetryable
public class ... {
#Override
public String forceError() {
throw new RuntimeException(someNastyMessage);
}
This pointcut would advise all public methods of a class annotated with #TransactionRetryable:
#Around("execution(public * *(..)) && within(#your.package.TransactionRetryable *)")

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