eugenp · saajn · Sep 5, 2024 · Aug 18, 2024 · Aug 18, 2024 · Aug 21, 2024
diff --git a/microservices-modules/micronaut-configuration/pom.xml b/microservices-modules/micronaut-configuration/pom.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.baeldung.micronaut</groupId>
     <artifactId>micronaut-configuration</artifactId>

diff --git a/...ut-configuration/src/main/java/com/baeldung/micronaut/environments/ServerApplication.java b/...ut-configuration/src/main/java/com/baeldung/micronaut/environments/ServerApplication.java
@@ -0,0 +1,14 @@
+package com.baeldung.micronaut.environments;
+
+import io.micronaut.context.env.Environment;
+import io.micronaut.runtime.Micronaut;
+
+public class ServerApplication {
+
+    public static void main(String[] args) {
+        Micronaut.build(args)
+            .defaultEnvironments(Environment.DEVELOPMENT)
+            .mainClass(ServerApplication.class)
+            .start();
+    }
+}
diff --git a/...onfiguration/src/main/java/com/baeldung/micronaut/environments/services/HostResolver.java b/...onfiguration/src/main/java/com/baeldung/micronaut/environments/services/HostResolver.java
@@ -0,0 +1,28 @@
+package com.baeldung.micronaut.environments.services;
+
+import java.util.Set;
+
+import io.micronaut.context.ApplicationContext;
+import jakarta.inject.Inject;
+import jakarta.inject.Singleton;
+
+@Singleton
+public class HostResolver {
+
+    @Inject
+    ApplicationContext applicationContext;
+
+    public String getHost() {
+        // avoid this messy code by using property files
+        Set<String> activeEnvironments = applicationContext.getEnvironment()
+            .getActiveNames();
+
+        if (activeEnvironments.contains("dev") || activeEnvironments.contains("local")) {
+            return "localhost";
+        } else if (activeEnvironments.contains("production")) {
+            return "my-service.us-west-2.amazonaws.com";
+        } else {
+            throw new RuntimeException("Unsupported environment: " + activeEnvironments);
+        }
+    }
+}
diff --git a/...java/com/baeldung/micronaut/environments/services/eventsourcing/EventSourcingService.java b/...java/com/baeldung/micronaut/environments/services/eventsourcing/EventSourcingService.java
@@ -0,0 +1,8 @@
+package com.baeldung.micronaut.environments.services.eventsourcing;
+
+public interface EventSourcingService {
+
+    // this method would be void, but for the purpose of our tutorial,
+    // we have it returning something, so that we can easily test it.
+    String sendEvent(String event);
+}
diff --git a/...com/baeldung/micronaut/environments/services/eventsourcing/KafkaEventSourcingService.java b/...com/baeldung/micronaut/environments/services/eventsourcing/KafkaEventSourcingService.java
@@ -0,0 +1,14 @@
+package com.baeldung.micronaut.environments.services.eventsourcing;
+
+import io.micronaut.context.annotation.Requires;
+import jakarta.inject.Singleton;
+
+@Singleton
+@Requires(env = "production")
+public class KafkaEventSourcingService implements EventSourcingService {
+
+    @Override
+    public String sendEvent(String event) {
+        return "using kafka to send message: [" + event + "]";
+    }
+}
diff --git a/.../com/baeldung/micronaut/environments/services/eventsourcing/VoidEventSourcingService.java b/.../com/baeldung/micronaut/environments/services/eventsourcing/VoidEventSourcingService.java
@@ -0,0 +1,15 @@
+package com.baeldung.micronaut.environments.services.eventsourcing;
+
+import io.micronaut.context.annotation.Requires;
+import io.micronaut.context.env.Environment;
+import jakarta.inject.Singleton;
+
+@Singleton
+@Requires(env = Environment.DEVELOPMENT)
+public class VoidEventSourcingService implements EventSourcingService {
+
+    @Override
+    public String sendEvent(String event) {
+        return "void service. [" + event + "] was not sent";
+    }
+}
diff --git a/.../java/com/baeldung/micronaut/environments/services/logging/ConsoleLoggingServiceImpl.java b/.../java/com/baeldung/micronaut/environments/services/logging/ConsoleLoggingServiceImpl.java
@@ -0,0 +1,12 @@
+package com.baeldung.micronaut.environments.services.logging;
+
+import jakarta.inject.Singleton;
+
+@Singleton
+public class ConsoleLoggingServiceImpl implements LoggingService {
+
+    @Override
+    public String log(String message) {
+        return "logging to console: [" + message + "]";
+    }
+}
diff --git a/...ain/java/com/baeldung/micronaut/environments/services/logging/FileLoggingServiceImpl.java b/...ain/java/com/baeldung/micronaut/environments/services/logging/FileLoggingServiceImpl.java
@@ -0,0 +1,16 @@
+package com.baeldung.micronaut.environments.services.logging;
+
+import io.micronaut.context.annotation.Replaces;
+import io.micronaut.context.annotation.Requires;
+import jakarta.inject.Singleton;
+
+@Singleton
+@Requires(env = { "production", "canary-production" })
+@Replaces(LoggingService.class)
+public class FileLoggingServiceImpl implements LoggingService {
+
+    @Override
+    public String log(String message) {
+        return "logging to some file: [" + message + "]";
+    }
+}
diff --git a/...on/src/main/java/com/baeldung/micronaut/environments/services/logging/LoggingService.java b/...on/src/main/java/com/baeldung/micronaut/environments/services/logging/LoggingService.java
@@ -0,0 +1,8 @@
+package com.baeldung.micronaut.environments.services.logging;
+
+public interface LoggingService {
+
+    // this method would be void, but for the purpose of our tutorial,
+    // we have it returning something, so that we can easily test it.
+    String log(String message);
+}
diff --git a/microservices-modules/micronaut-configuration/src/main/resources/application-dev.yml b/microservices-modules/micronaut-configuration/src/main/resources/application-dev.yml
@@ -0,0 +1,3 @@
+service:
+  test:
+    property: 'something-in-dev'
diff --git a/...ng/micronaut/environments/services/eventsourcing/DevEnvironmentEventSourcingUnitTest.java b/...ng/micronaut/environments/services/eventsourcing/DevEnvironmentEventSourcingUnitTest.java
@@ -0,0 +1,39 @@
+package com.baeldung.micronaut.environments.services.eventsourcing;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.jupiter.api.Test;
+
+import io.micronaut.context.ApplicationContext;
+import io.micronaut.context.annotation.Property;
+import io.micronaut.test.extensions.junit5.annotation.MicronautTest;
+import jakarta.inject.Inject;
+
+@MicronautTest(environments = { "dev" })
+public class DevEnvironmentEventSourcingUnitTest {
+
+    @Inject
+    EventSourcingService eventSourcingService;
+    @Inject
+    ApplicationContext applicationContext;
+    @Property(name = "service.test.property")
+    String testProperty;
+
+    @Test
+    public void whenEnvironmentIsSetToDev_thenActiveEnvironmentsAreTestAndDev() {
+        assertThat(applicationContext.getEnvironment()
+            .getActiveNames()).containsExactlyInAnyOrder("test", "dev");
+    }
+
+    @Test
+    public void whenEnvironmentIsSetToDev_thenTestPropertyGetsValueFromDev() {
+        assertThat(testProperty).isEqualTo("something-in-dev");
+    }
+
+    @Test
+    public void givenEnvironmentIsSetToDev_whenSendEvent_thenVoidServiceIsUsed() {
+        String devEvent = eventSourcingService.sendEvent("something");
+
+        assertThat(devEvent).isEqualTo("void service. [something] was not sent");
+    }
+}
diff --git a/...icronaut/environments/services/eventsourcing/InvalidEnvironmentEventSourcingUnitTest.java b/...icronaut/environments/services/eventsourcing/InvalidEnvironmentEventSourcingUnitTest.java
@@ -0,0 +1,38 @@
+package com.baeldung.micronaut.environments.services.eventsourcing;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+import org.junit.jupiter.api.Test;
+
+import com.baeldung.micronaut.environments.ServerApplication;
+
+import io.micronaut.context.ApplicationContext;
+import io.micronaut.context.exceptions.NoSuchBeanException;
+import io.micronaut.runtime.Micronaut;
+
+public class InvalidEnvironmentEventSourcingUnitTest {
+
+    @Test
+    public void whenEnvironmentIsNotSet_thenEventSourcingServiceBeanIsNotCreated() {
+        ApplicationContext applicationContext = Micronaut.run(ServerApplication.class);
+        applicationContext.start();
+
+        assertThat(applicationContext.getEnvironment()
+            .getActiveNames()).containsExactly("test");
+        assertThatThrownBy(() -> applicationContext.getBean(EventSourcingService.class)).isInstanceOf(NoSuchBeanException.class)
+            .hasMessageContaining("None of the required environments [production] are active: [test]");
+    }
+
+    @Test
+    public void whenEnvironmentIsNotSet_thenTestPropertyGetsValueFromDeductedEnvironment() {
+        ApplicationContext applicationContext = Micronaut.run(ServerApplication.class);
+        applicationContext.start();
+
+        assertThat(applicationContext.getEnvironment()
+            .getActiveNames()).containsExactly("test");
+        assertThat(applicationContext.getProperty("service.test.property", String.class)).isNotEmpty();
+        assertThat(applicationContext.getProperty("service.test.property", String.class)
+            .get()).isEqualTo("something-in-test");
+    }
+}
diff --git a/...ronaut/environments/services/eventsourcing/MultipleEnvironmentsEventSourcingUnitTest.java b/...ronaut/environments/services/eventsourcing/MultipleEnvironmentsEventSourcingUnitTest.java
@@ -0,0 +1,48 @@
+package com.baeldung.micronaut.environments.services.eventsourcing;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+import org.junit.jupiter.api.Test;
+
+import io.micronaut.context.ApplicationContext;
+import io.micronaut.context.exceptions.NonUniqueBeanException;
+
+public class MultipleEnvironmentsEventSourcingUnitTest {
+
+    @Test
+    public void whenEnvironmentIsSetToBothProductionAndDev_thenEventSourcingServiceBeanHasConflict() {
+        ApplicationContext applicationContext = ApplicationContext.builder("dev", "production")
+            .build();
+        applicationContext.start();
+
+        assertThat(applicationContext.getEnvironment()
+            .getActiveNames()).containsExactly("test", "dev", "production");
+        assertThatThrownBy(() -> applicationContext.getBean(EventSourcingService.class)).isInstanceOf(NonUniqueBeanException.class)
+            .hasMessageStartingWith("Multiple possible bean candidates found: [");
+    }
+
+    @Test
+    public void whenEnvironmentIsSetToBothProductionAndDev_thenTestPropertyGetsValueBasedOnPriority() {
+        ApplicationContext applicationContext = ApplicationContext.builder("dev", "production")
+            .build();
+        applicationContext.start();
+
+        assertThat(applicationContext.getEnvironment()
+            .getActiveNames()).containsExactly("test", "dev", "production");
+        assertThat(applicationContext.getProperty("service.test.property", String.class)).isNotEmpty();
+        assertThat(applicationContext.getProperty("service.test.property", String.class)
+            .get()).isEqualTo("something-in-dev");
+    }
+
+    @Test
+    public void whenEnvironmentIsSetToBothProductionAndDev_thenMissingPropertyIsEmpty() {
+        ApplicationContext applicationContext = ApplicationContext.builder("dev", "production")
+            .build();
+        applicationContext.start();
+
+        assertThat(applicationContext.getEnvironment()
+            .getActiveNames()).containsExactly("test", "dev", "production");
+        assertThat(applicationContext.getProperty("service.dummy.property", String.class)).isEmpty();
+    }
+}
diff --git a/...onaut/environments/services/eventsourcing/ProductionEnvironmentEventSourcingUnitTest.java b/...onaut/environments/services/eventsourcing/ProductionEnvironmentEventSourcingUnitTest.java
@@ -0,0 +1,31 @@
+package com.baeldung.micronaut.environments.services.eventsourcing;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.jupiter.api.Test;
+
+import io.micronaut.context.ApplicationContext;
+import io.micronaut.test.extensions.junit5.annotation.MicronautTest;
+import jakarta.inject.Inject;
+
+@MicronautTest(environments = { "production" })
+public class ProductionEnvironmentEventSourcingUnitTest {
+
+    @Inject
+    EventSourcingService eventSourcingService;
+    @Inject
+    ApplicationContext applicationContext;
+
+    @Test
+    public void whenEnvironmentIsSetToProduction_thenActiveEnvironmentsAreTestAndProduction() {
+        assertThat(applicationContext.getEnvironment()
+            .getActiveNames()).containsExactlyInAnyOrder("test", "production");
+    }
+
+    @Test
+    public void givenEnvironmentIsSetToProduction_whenSendEvent_thenKafkaServiceIsUsed() {
+        String devEvent = eventSourcingService.sendEvent("something");
+
+        assertThat(devEvent).isEqualTo("using kafka to send message: [something]");
+    }
+}
diff --git a/...dung/micronaut/environments/services/hostresolver/DevEnvironmentHostResolverUnitTest.java b/...dung/micronaut/environments/services/hostresolver/DevEnvironmentHostResolverUnitTest.java
@@ -0,0 +1,33 @@
+package com.baeldung.micronaut.environments.services.hostresolver;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.jupiter.api.Test;
+
+import com.baeldung.micronaut.environments.services.HostResolver;
+
+import io.micronaut.context.ApplicationContext;
+import io.micronaut.test.extensions.junit5.annotation.MicronautTest;
+import jakarta.inject.Inject;
+
+@MicronautTest(environments = { "dev" })
+public class DevEnvironmentHostResolverUnitTest {
+
+    @Inject
+    HostResolver hostResolver;
+    @Inject
+    ApplicationContext applicationContext;
+
+    @Test
+    public void whenEnvironmentIsSetToDev_thenActiveEnvironmentsAreTestAndDev() {
+        assertThat(applicationContext.getEnvironment()
+            .getActiveNames()).containsExactlyInAnyOrder("test", "dev");
+    }
+
+    @Test
+    public void givenEnvironmentIsSetToDev_whenGetHost_thenTheResolverReturnsLocalhost() {
+        String devHost = hostResolver.getHost();
+
+        assertThat(devHost).isEqualTo("localhost");
+    }
+}
diff --git a/.../micronaut/environments/services/hostresolver/InvalidEnvironmentHostResolverUnitTest.java b/.../micronaut/environments/services/hostresolver/InvalidEnvironmentHostResolverUnitTest.java
@@ -0,0 +1,33 @@
+package com.baeldung.micronaut.environments.services.hostresolver;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+import org.junit.jupiter.api.Test;
+
+import com.baeldung.micronaut.environments.services.HostResolver;
+
+import io.micronaut.context.ApplicationContext;
+import io.micronaut.test.extensions.junit5.annotation.MicronautTest;
+import jakarta.inject.Inject;
+
+@MicronautTest(environments = { "no-mans-land" })
+public class InvalidEnvironmentHostResolverUnitTest {
+
+    @Inject
+    HostResolver hostResolver;
+    @Inject
+    ApplicationContext applicationContext;
+
+    @Test
+    public void whenEnvironmentIsSetToIrrelevant_thenActiveEnvironmentsAreTheExpectedOnes() {
+        assertThat(applicationContext.getEnvironment()
+            .getActiveNames()).containsExactlyInAnyOrder("test", "no-mans-land");
+    }
+
+    @Test
+    public void givenEnvironmentIsSetToIrrelevant_whenGetHost_throwsUnsupportedEnvironmentException() {
+        assertThatThrownBy(() -> hostResolver.getHost()).isInstanceOf(RuntimeException.class)
+            .hasMessageContaining("Unsupported environment: ");
+    }
+}
diff --git a/...ng/micronaut/environments/services/hostresolver/LocalEnvironmentHostResolverUnitTest.java b/...ng/micronaut/environments/services/hostresolver/LocalEnvironmentHostResolverUnitTest.java
@@ -0,0 +1,33 @@
+package com.baeldung.micronaut.environments.services.hostresolver;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.jupiter.api.Test;
+
+import com.baeldung.micronaut.environments.services.HostResolver;
+
+import io.micronaut.context.ApplicationContext;
+import io.micronaut.test.extensions.junit5.annotation.MicronautTest;
+import jakarta.inject.Inject;
+
+@MicronautTest(environments = { "local" })
+public class LocalEnvironmentHostResolverUnitTest {
+
+    @Inject
+    HostResolver hostResolver;
+    @Inject
+    ApplicationContext applicationContext;
+
+    @Test
+    public void whenEnvironmentIsSetToLocal_thenActiveEnvironmentsAreTestAndLocal() {
+        assertThat(applicationContext.getEnvironment()
+            .getActiveNames()).containsExactlyInAnyOrder("test", "local");
+    }
+
+    @Test
+    public void givenEnvironmentIsSetToLocal_whenGetHost_thenTheResolverReturnsLocalhost() {
+        String localHost = hostResolver.getHost();
+
+        assertThat(localHost).isEqualTo("localhost");
+    }
+}