ServiceFinder defaults to ServiceLookupIteratorProvider

.gitignore

@@ -27,6 +27,7 @@ nb-configuration.xml
 .settings/*
 .project
 .classpath
+.factorypath
 
 # Maven plugins noise
 dependency-reduced-pom.xml

core-common/src/main/java/org/glassfish/jersey/internal/OsgiRegistry.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2022 Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2024 Oracle and/or its affiliates. All rights reserved.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0, which is available at
@@ -106,7 +106,7 @@ public static synchronized OsgiRegistry getInstance() {
 
     private final class OsgiServiceFinder extends ServiceFinder.ServiceIteratorProvider {
 
-        final ServiceFinder.ServiceIteratorProvider defaultIterator = new ServiceFinder.DefaultServiceIteratorProvider();
+        final ServiceFinder.ServiceIteratorProvider defaultIterator = new ServiceFinder.ServiceReflectionIteratorProvider();
 
         @Override
         public <T> Iterator<T> createIterator(

core-common/src/main/java/org/glassfish/jersey/internal/ServiceFinder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2010, 2018 Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2010, 2024 Oracle and/or its affiliates. All rights reserved.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0, which is available at
@@ -31,10 +31,12 @@
 import java.util.Iterator;
 import java.util.List;
 import java.util.NoSuchElementException;
+import java.util.ServiceLoader;
 import java.util.Set;
 import java.util.TreeSet;
 import java.util.logging.Level;
 import java.util.logging.Logger;
+import java.util.stream.Collectors;
 
 import org.glassfish.jersey.internal.util.ReflectionHelper;
 
@@ -229,7 +231,9 @@ public static <T> ServiceFinder<T> find(final Class<T> service, final ClassLoade
      *                class loader (or, failing that the bootstrap class loader) is to
      *                be used
      * @param ignoreOnClassNotFound If a provider cannot be loaded by the class loader
-     *                              then move on to the next available provider.
+     *                              then move on to the next available provider. This value does
+     *                              not apply when the {@link ServiceIteratorProvider} is set to
+     *                              {@link ServiceLookupIteratorProvider}.
      * @throws ServiceConfigurationError If a provider-configuration file violates the specified format
      *                                   or names a provider class that cannot be found and instantiated
      * @see #find(Class)
@@ -279,7 +283,10 @@ public static <T> ServiceFinder<T> find(final Class<T> service)
      * </pre>
      * @param service The service's abstract service class
      * @param ignoreOnClassNotFound If a provider cannot be loaded by the class loader
-     *                              then move on to the next available provider.
+     *                              then move on to the next available provider. This value does
+     *                              not apply when the {@link ServiceIteratorProvider} is set to
+     *                              {@link ServiceLookupIteratorProvider}.
+     *
      * @throws ServiceConfigurationError If a provider-configuration file violates the specified format
      *                                   or names a provider class that cannot be found and instantiated
      * @see #find(Class, ClassLoader)
@@ -312,7 +319,7 @@ public static ServiceFinder<?> find(final String serviceName) throws ServiceConf
      * Register the service iterator provider to iterate on provider instances
      * or classes.
      * <p>
-     * The default implementation registered, {@link DefaultServiceIteratorProvider},
+     * The default implementation registered, {@link ServiceLookupIteratorProvider},
      * looks up provider classes in META-INF/service files.
      * <p>
      * This method must be called prior to any attempts to obtain provider
@@ -790,7 +797,7 @@ private void handleClassNotFoundException() throws ServiceConfigurationError {
      * Supports iteration of provider instances or classes.
      * <p>
      * The default implementation looks up provider classes from META-INF/services
-     * files, see {@link DefaultServiceIteratorProvider}.
+     * files, see {@link ServiceLookupIteratorProvider}.
      * This implementation may be overridden by invoking
      * {@link ServiceFinder#setIteratorProvider(org.glassfish.jersey.internal.ServiceFinder.ServiceIteratorProvider)}.
      */
@@ -806,7 +813,7 @@ private static ServiceIteratorProvider getInstance() {
                 synchronized (sipLock) {
                     result = sip;
                     if (result == null) { // Second check (with locking)
-                        sip = result = new DefaultServiceIteratorProvider();
+                        sip = result = new ServiceLookupIteratorProvider();
                     }
                 }
             }
@@ -834,7 +841,9 @@ private static void setInstance(final ServiceIteratorProvider sip) throws Securi
          *        classes.
          * @param ignoreOnClassNotFound if true ignore an instance if the
          *        corresponding provider class if cannot be found,
-         *        otherwise throw a {@link ClassNotFoundException}.
+         *        otherwise throw a {@link ClassNotFoundException}. This value does
+         *        not apply when the {@link ServiceIteratorProvider} is set to
+         *        {@link ServiceLookupIteratorProvider}.
          * @return the provider instance iterator.
          */
         public abstract <T> Iterator<T> createIterator(Class<T> service,
@@ -851,6 +860,8 @@ public abstract <T> Iterator<T> createIterator(Class<T> service,
          * @param ignoreOnClassNotFound if true ignore the provider class if
          *        cannot be found,
          *        otherwise throw a {@link ClassNotFoundException}.
+         *        This value does not apply when the {@link ServiceIteratorProvider}
+         *        is set to {@link ServiceLookupIteratorProvider}.
          * @return the provider class iterator.
          */
         public abstract <T> Iterator<Class<T>> createClassIterator(Class<T> service,
@@ -860,13 +871,10 @@ public abstract <T> Iterator<Class<T>> createClassIterator(Class<T> service,
     }
 
     /**
-     * The default service iterator provider that looks up provider classes in
+     * The service iterator provider that looks up provider classes in
      * META-INF/services files.
-     * <p>
-     * This class may utilized if a {@link ServiceIteratorProvider} needs to
-     * reuse the default implementation.
      */
-    public static final class DefaultServiceIteratorProvider extends ServiceIteratorProvider {
+    public static final class ServiceReflectionIteratorProvider extends ServiceIteratorProvider {
 
         @Override
         public <T> Iterator<T> createIterator(final Class<T> service, final String serviceName,
@@ -880,4 +888,41 @@ public <T> Iterator<Class<T>> createClassIterator(final Class<T> service, final
             return new LazyClassIterator<T>(service, serviceName, loader, ignoreOnClassNotFound);
         }
     }
+
+    /**
+     * The service iterator provider that looks up provider classes in
+     * META-INF/services files using {@link ServiceLoader}.
+     */
+    public static final class ServiceLookupIteratorProvider extends ServiceIteratorProvider {
+
+        @Override
+        public <T> Iterator<T> createIterator(final Class<T> service, final String serviceName,
+                                              final ClassLoader loader, final boolean ignoreOnClassNotFound) {
+            Class<T> clazz = fixGenericService(service, serviceName, loader, ignoreOnClassNotFound);
+            return ServiceLoader.load(clazz, loader).iterator();
+        }
+
+        @Override
+        public <T> Iterator<Class<T>> createClassIterator(final Class<T> service, final String serviceName,
+                                                          final ClassLoader loader, final boolean ignoreOnClassNotFound) {
+            Class<T> clazz = fixGenericService(service, serviceName, loader, ignoreOnClassNotFound);
+            List<Class<T>> classes = ServiceLoader.load(clazz, loader).stream()
+                    .map(provider -> (Class<T>) provider.type())
+                    .collect(Collectors.toList());
+            return classes.iterator();
+        }
+
+        private <T> Class<T> fixGenericService(final Class<T> service, final String serviceName,
+                final ClassLoader loader, final boolean ignoreOnClassNotFound) {
+            Class<T> clazz = service;
+            if (Object.class == service) {
+                try {
+                    clazz = (Class<T>) ReflectionHelper.classForNameWithExceptionPEA(serviceName, loader).run();
+                } catch (Exception e) {
+                    // Ignore it. Later, the service implementation will not be loaded.
+                }
+            }
+            return clazz;
+        }
+    }
 }

core-server/src/test/java/org/glassfish/jersey/server/internal/ServiceExample.java

@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2024 Oracle and/or its affiliates. All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0, which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the
+ * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
+ * version 2 with the GNU Classpath Exception, which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ */
+
+package org.glassfish.jersey.server.internal;
+
+public interface ServiceExample {}

core-server/src/test/java/org/glassfish/jersey/server/internal/ServiceFinderTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014, 2022 Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2014, 2024 Oracle and/or its affiliates. All rights reserved.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0, which is available at
@@ -16,29 +16,127 @@
 
 package org.glassfish.jersey.server.internal;
 
+import static org.glassfish.jersey.server.JarUtils.createJarFile;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.fail;
+
+import jakarta.ws.rs.container.DynamicFeature;
+import jakarta.ws.rs.core.Configurable;
+
 import java.io.IOException;
 import java.lang.reflect.Method;
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.Iterator;
 import java.util.Map;
 import java.util.Set;
 
 import org.glassfish.jersey.internal.ServiceFinder;
+import org.glassfish.jersey.internal.ServiceFinder.ServiceIteratorProvider;
+import org.glassfish.jersey.internal.ServiceFinder.ServiceLookupIteratorProvider;
+import org.glassfish.jersey.internal.ServiceFinder.ServiceReflectionIteratorProvider;
 import org.glassfish.jersey.server.JarUtils;
-
+import org.glassfish.jersey.server.JaxRsFeatureRegistrationTest.DynamicFeatureImpl;
+import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.Test;
-import static org.glassfish.jersey.server.JarUtils.createJarFile;
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertTrue;
 
 /**
  * @author Michal Gajdos
  */
 public class ServiceFinderTest {
 
+    @AfterAll
+    public static void afterClass() {
+        // Restore the default
+        ServiceFinder.setIteratorProvider(null);
+    }
+
+    @Test
+    public void testExistingClass() {
+        ServiceIteratorProvider[] providers = new ServiceIteratorProvider[] {
+                new ServiceReflectionIteratorProvider(), new ServiceLookupIteratorProvider()};
+        for (ServiceIteratorProvider provider : providers) {
+            ServiceFinder.setIteratorProvider(provider);
+            ServiceFinder<?> serviceFinder = ServiceFinder.find(DynamicFeature.class);
+            checks(provider, serviceFinder);
+            serviceFinder = ServiceFinder.find("jakarta.ws.rs.container.DynamicFeature");
+            checks(provider, serviceFinder);
+        }
+    }
+
+    @Test
+    public void testMissingService() {
+        ServiceIteratorProvider[] providers = new ServiceIteratorProvider[] {
+                new ServiceReflectionIteratorProvider(), new ServiceLookupIteratorProvider()};
+        for (ServiceIteratorProvider provider : providers) {
+            ServiceFinder.setIteratorProvider(provider);
+            ServiceFinder<?> serviceFinder = ServiceFinder.find(Configurable.class);
+            assertFalse(serviceFinder.iterator().hasNext());
+            serviceFinder = ServiceFinder.find("jakarta.ws.rs.core.Configurable");
+            assertFalse(serviceFinder.iterator().hasNext());
+        }
+    }
+
+    @Test
+    public void testClassNotFound() {
+        ServiceIteratorProvider[] providers = new ServiceIteratorProvider[] {
+                new ServiceReflectionIteratorProvider(), new ServiceLookupIteratorProvider()};
+        for (ServiceIteratorProvider provider : providers) {
+            ServiceFinder.setIteratorProvider(provider);
+            ServiceFinder<?> serviceFinder = ServiceFinder.find("doesNotExist");
+            assertFalse(serviceFinder.iterator().hasNext());
+        }
+    }
+
+    @Test
+    public void testServiceReflectionIteratorProviderImplementationNotFound() {
+        ServiceFinder.setIteratorProvider(new ServiceReflectionIteratorProvider());
+        ServiceFinder<?> serviceFinder = ServiceFinder.find(ServiceExample.class, true);
+        assertFalse(serviceFinder.iterator().hasNext());
+        serviceFinder = ServiceFinder.find(ServiceExample.class, false);
+        try {
+            serviceFinder.iterator().hasNext();
+            fail("It is expected to fail");
+        } catch (org.glassfish.jersey.internal.ServiceConfigurationError e) {
+            // Expected
+        }
+    }
+
+    @Test
+    public void testServiceLookupIteratorProviderImplementationNotFound() {
+        ServiceFinder.setIteratorProvider(new ServiceLookupIteratorProvider());
+        ServiceFinder<?> serviceFinder = ServiceFinder.find(ServiceExample.class, true);
+        Iterator<?> iterator = serviceFinder.iterator();
+        try {
+            iterator.hasNext();
+            iterator.next();
+            fail("It is expected to fail");
+        } catch (java.util.ServiceConfigurationError e) {
+            // Expected
+        }
+        serviceFinder = ServiceFinder.find(ServiceExample.class, false);
+        iterator = serviceFinder.iterator();
+        try {
+            iterator.hasNext();
+            iterator.next();
+            fail("It is expected to fail");
+        } catch (java.util.ServiceConfigurationError e) {
+            // Expected
+        }
+    }
+
+    private void checks(ServiceIteratorProvider provider, ServiceFinder<?> serviceFinder) {
+        Iterator<?> iterator = serviceFinder.iterator();
+        assertTrue(iterator.hasNext(), "No instance found with " + provider);
+        Object dynamicFeature = iterator.next();
+        assertEquals(DynamicFeatureImpl.class, dynamicFeature.getClass());
+    }
+
     @Test
     public void testJarTopLevel() throws Exception {
         final Map<String, String> map = new HashMap<>();
@@ -49,6 +147,7 @@ public void testJarTopLevel() throws Exception {
         final String path = ServiceFinderTest.class.getResource("").getPath();
         final ClassLoader classLoader = createClassLoader(path.substring(0, path.indexOf("org")), map);
 
+        ServiceFinder.setIteratorProvider(new ServiceReflectionIteratorProvider());
         final ServiceFinder<?> finder = createServiceFinder(classLoader, "jaxrs-components");
 
         final Set<Class<?>> s = new HashSet<>();

core-server/src/test/resources/META-INF/services/org.glassfish.jersey.server.internal.ServiceExample

@@ -0,0 +1 @@
+unknown