Support injectable loggers

docs/src/main/asciidoc/logging.adoc

@@ -51,6 +51,32 @@ public class ExampleResource {
 
 NOTE: If you use JBoss Logging but one of your libraries uses a different logging API, you may need to configure a link:#logging-adapters[Logging Adapter].
 
+You can also inject a configured `org.jboss.logging.Logger` instance in your beans and resource classes.
+
+[source, java]
+----
+import org.jboss.logging.Logger;
+
+@ApplicationScoped
+class SimpleBean {
+
+   @Inject
+   Logger log; <1>
+
+   @LoggerName("foo")
+   Logger fooLog; <2>
+
+   public void ping() {
+     log.info("Simple!");
+     fooLog.info("Goes to _foo_ logger!");
+   }
+}
+----
+<1> The FQCN of the declaring class is used as a logger name, i.e. `org.jboss.logging.Logger.getLogger(SimpleBean.class)` will be used.
+<2> In this case, the name _foo_ is used as a logger name, i.e. `org.jboss.logging.Logger.getLogger("foo")` will be used.
+
+NOTE: The logger instances are cached internally. Therefore, a logger injected e.g. into a `@RequestScoped` bean is shared for all bean instances to avoid possible performance penalty associated with logger instantiation.
+
 === What about Apache Log4j ?
 
 link:https://logging.apache.org/log4j/2.x/[Log4j] is a logging implementation: it contains a logging backend and a logging facade.

extensions/arc/deployment/src/main/java/io/quarkus/arc/deployment/ArcProcessor.java

@@ -54,6 +54,7 @@
 import io.quarkus.arc.runtime.BeanContainer;
 import io.quarkus.arc.runtime.LaunchModeProducer;
 import io.quarkus.arc.runtime.LifecycleEventRunner;
+import io.quarkus.arc.runtime.LoggerProducer;
 import io.quarkus.bootstrap.BootstrapDebug;
 import io.quarkus.deployment.Capabilities;
 import io.quarkus.deployment.Capability;
@@ -509,6 +510,11 @@ AdditionalBeanBuildItem launchMode() {
         return new AdditionalBeanBuildItem(LaunchModeProducer.class);
     }
 
+    @BuildStep
+    AdditionalBeanBuildItem loggerProducer() {
+        return new AdditionalBeanBuildItem(LoggerProducer.class);
+    }
+
     @BuildStep
     CustomScopeAnnotationsBuildItem exposeCustomScopeNames(List<ContextRegistrarBuildItem> contextBuildItems) {
         Set<DotName> names = new HashSet<>();

extensions/arc/deployment/src/test/java/io/quarkus/arc/test/log/InjectedLoggerTest.java

@@ -0,0 +1,82 @@
+package io.quarkus.arc.test.log;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import javax.enterprise.context.ApplicationScoped;
+import javax.enterprise.context.Dependent;
+import javax.inject.Inject;
+
+import org.jboss.logging.Logger;
+import org.jboss.shrinkwrap.api.ShrinkWrap;
+import org.jboss.shrinkwrap.api.spec.JavaArchive;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import io.quarkus.arc.log.LoggerName;
+import io.quarkus.test.QuarkusUnitTest;
+
+public class InjectedLoggerTest {
+
+    @RegisterExtension
+    static final QuarkusUnitTest config = new QuarkusUnitTest()
+            .setArchiveProducer(() -> ShrinkWrap.create(JavaArchive.class)
+                    .addClasses(SimpleBean.class));
+
+    @Inject
+    SimpleBean simpleBean;
+
+    @Inject
+    AnotherSimpleBean anotherSimpleBean;
+
+    @Test
+    public void testInjectedLogger() {
+        assertEquals(SimpleBean.class.getName(), simpleBean.getLog().getName());
+        assertEquals("shared", simpleBean.getSharedLog().getName());
+        assertEquals(AnotherSimpleBean.class.getName(), anotherSimpleBean.getLog().getName());
+        assertEquals(simpleBean.getSharedLog(), anotherSimpleBean.getSharedLog());
+    }
+
+    @ApplicationScoped
+    static class SimpleBean {
+
+        @Inject
+        Logger log;
+
+        @LoggerName("shared")
+        Logger sharedLog;
+
+        public Logger getLog() {
+            log.info("Someone is here!");
+            return log;
+        }
+
+        public Logger getSharedLog() {
+            return sharedLog;
+        }
+
+    }
+
+    @Dependent
+    static class AnotherSimpleBean {
+
+        private final Logger log;
+
+        @LoggerName("shared")
+        Logger sharedLog;
+
+        public AnotherSimpleBean(Logger log) {
+            this.log = log;
+        }
+
+        public Logger getLog() {
+            return log;
+        }
+
+        public Logger getSharedLog() {
+            sharedLog.info("Yet another someone is here!");
+            return sharedLog;
+        }
+
+    }
+
+}

extensions/arc/runtime/src/main/java/io/quarkus/arc/log/LoggerName.java

@@ -0,0 +1,48 @@
+package io.quarkus.arc.log;
+
+import static java.lang.annotation.ElementType.FIELD;
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.PARAMETER;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import javax.enterprise.util.AnnotationLiteral;
+import javax.enterprise.util.Nonbinding;
+import javax.inject.Qualifier;
+
+@Qualifier
+@Retention(RUNTIME)
+@Target({ FIELD, PARAMETER, METHOD })
+public @interface LoggerName {
+
+    /**
+     * The logger name must not be empty.
+     * 
+     * @return the logger name
+     */
+    @Nonbinding
+    String value();
+
+    /**
+     * Supports inline instantiation of this qualifier.
+     */
+    public static final class Literal extends AnnotationLiteral<LoggerName> implements LoggerName {
+
+        private static final long serialVersionUID = 1L;
+
+        private final String value;
+
+        public Literal(String value) {
+            this.value = value;
+        }
+
+        @Override
+        public String value() {
+            return value;
+        }
+
+    }
+
+}

extensions/arc/runtime/src/main/java/io/quarkus/arc/runtime/LoggerProducer.java

@@ -0,0 +1,49 @@
+package io.quarkus.arc.runtime;
+
+import java.lang.annotation.Annotation;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+
+import javax.annotation.PreDestroy;
+import javax.enterprise.context.Dependent;
+import javax.enterprise.inject.Produces;
+import javax.enterprise.inject.spi.InjectionPoint;
+import javax.inject.Singleton;
+
+import org.jboss.logging.Logger;
+
+import io.quarkus.arc.log.LoggerName;
+
+@Singleton
+public class LoggerProducer {
+
+    private final ConcurrentMap<String, Logger> loggers = new ConcurrentHashMap<>();
+
+    @Dependent
+    @Produces
+    Logger getSimpleLogger(InjectionPoint injectionPoint) {
+        return loggers.computeIfAbsent(injectionPoint.getMember().getDeclaringClass().getName(), Logger::getLogger);
+    }
+
+    @LoggerName("")
+    @Dependent
+    @Produces
+    Logger getLoggerWithCustomName(InjectionPoint injectionPoint) {
+        String name = null;
+        for (Annotation qualifier : injectionPoint.getQualifiers()) {
+            if (qualifier.annotationType().equals(LoggerName.class)) {
+                name = ((LoggerName) qualifier).value();
+            }
+        }
+        if (name == null || name.isEmpty()) {
+            throw new IllegalStateException("Unable to derive the logger name at " + injectionPoint);
+        }
+        return loggers.computeIfAbsent(name, Logger::getLogger);
+    }
+
+    @PreDestroy
+    void destroy() {
+        loggers.clear();
+    }
+
+}