How can we do incremental migration of Spring app to Micronaut ? I am looking for away to migrate Spring Beans to Micronaut. I tried to consume a Micronaut bean from a Spring app following the docs but it is not wokring
My example test: https://github.com/luistrigueiros/micronaut-expose-spring-beans/blob/master/src/test/groovy/example/ConsumeBeanSpec.groovy
import groovy.util.logging.Slf4j
import org.springframework.test.context.ContextConfiguration
import spock.lang.Specification
import javax.inject.Inject
@Slf4j
@ContextConfiguration(classes = [Config])
class ConsumeBeanSpec extends Specification {
@Inject
ConsumerBean consumerBean
def "should be able to do something"(){
expect:
consumerBean.doSomething()
}
}
The current stack trace error: ... 36 common frames omitted Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'example.ExposedBean' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {} at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1509) at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1104) at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1065) at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:815) at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:721) ... 54 common frames omitted
java.lang.IllegalStateException: Failed to load ApplicationContext
at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:125)
at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:108)
at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:117)
at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:83)
at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:246)
at org.spockframework.spring.SpringTestContextManager.prepareTestInstance(SpringTestContextManager.java:49)
at org.spockframework.spring.SpringInterceptor.interceptSetupMethod(SpringInterceptor.java:42)
at org.spockframework.runtime.extension.AbstractMethodInterceptor.intercept(AbstractMethodInterceptor.java:28)
at org.spockframework.runtime.extension.MethodInvocation.proceed(MethodInvocation.java:87)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'consumerBean' defined in file [C:\tools\micronaut.io\study\micronaut-expose-spring-beans\out\production\classes\example\ConsumerBean.class]: Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'example.ExposedBean' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {} at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:729) at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:192) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1274) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1131) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:541)
I have sent a PR to https://github.com/luistrigueiros/micronaut-expose-spring-beans/pull/1 which allows your test to pass.
As the javadocs at https://docs.micronaut.io/1.0.0.M1/api/io/micronaut/spring/beans/MicronautBeanProcessor.html, MicronautBeanProcessor only processes singleton beans.
That is imposed at https://github.com/micronaut-projects/micronaut-core/blob/0108642b11d0c6d7f11bcffc85b357e823c98d42/spring/src/main/java/io/micronaut/spring/beans/MicronautBeanProcessor.java#L109.
The javadoc is clear about that. We will add some clarity about that in the user guide.