Add HttpServiceClient and registrar

See gh-35244

spring-web/src/main/java/org/springframework/web/service/registry/AbstractHttpServiceRegistrar.java

@@ -18,6 +18,7 @@ package org.springframework.web.service.registry;
 
 import java.util.Arrays;
 import java.util.Objects;
+import java.util.stream.Stream;
 
 import org.jspecify.annotations.Nullable;
 
@@ -186,7 +187,8 @@ public abstract class AbstractHttpServiceRegistrar implements
 	protected abstract void registerHttpServices(
 			GroupRegistry registry, AnnotationMetadata importingClassMetadata);
 
-	private ClassPathScanningCandidateComponentProvider getScanner() {
+
+	protected Stream<BeanDefinition> findHttpServices(String basePackage) {
 		if (this.scanner == null) {
 			Assert.state(this.environment != null, "Environment has not been set");
 			Assert.state(this.resourceLoader != null, "ResourceLoader has not been set");
@@ -194,7 +196,7 @@ public abstract class AbstractHttpServiceRegistrar implements
 			this.scanner.setEnvironment(this.environment);
 			this.scanner.setResourceLoader(this.resourceLoader);
 		}
-		return this.scanner;
+		return this.scanner.findCandidateComponents(basePackage).stream();
 	}
 
 	private void mergeGroups(RootBeanDefinition proxyRegistryBeanDef) {
@@ -244,10 +246,15 @@ public abstract class AbstractHttpServiceRegistrar implements
 		interface GroupSpec {
 
 			/**
-			 * List HTTP Service types to create proxies for.
+			 * Register HTTP Service types to create proxies for.
 			 */
 			GroupSpec register(Class<?>... serviceTypes);
 
+			/**
+			 * Register HTTP Service types using fully qualified type names.
+			 */
+			GroupSpec registerTypeNames(String... serviceTypes);
+
 			/**
 			 * Detect HTTP Service types in the given packages, looking for
 			 * interfaces with a type and/or method {@link HttpExchange} annotation.
@@ -258,7 +265,6 @@ public abstract class AbstractHttpServiceRegistrar implements
 			 * Variant of {@link #detectInBasePackages(Class[])} with a String package name.
 			 */
 			GroupSpec detectInBasePackages(String... packageNames);
-
 		}
 	}
 
@@ -288,6 +294,12 @@ public abstract class AbstractHttpServiceRegistrar implements
 				return this;
 			}
 
+			@Override
+			public GroupRegistry.GroupSpec registerTypeNames(String... serviceTypes) {
+				Arrays.stream(serviceTypes).forEach(this::registerServiceTypeName);
+				return this;
+			}
+
 			@Override
 			public GroupRegistry.GroupSpec detectInBasePackages(Class<?>... packageClasses) {
 				Arrays.stream(packageClasses).map(Class::getPackageName).forEach(this::detectInBasePackage);
@@ -301,7 +313,7 @@ public abstract class AbstractHttpServiceRegistrar implements
 			}
 
 			private void detectInBasePackage(String packageName) {
-				getScanner().findCandidateComponents(packageName).stream()
+				findHttpServices(packageName)
 						.map(BeanDefinition::getBeanClassName)
 						.filter(Objects::nonNull)
 						.forEach(this::registerServiceTypeName);

spring-web/src/main/java/org/springframework/web/service/registry/HttpServiceClient.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2002-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.service.registry;
+
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+import org.springframework.core.annotation.AliasFor;
+
+/**
+ * Annotation to mark an HTTP Service interface as a candidate client proxy creation.
+ * Supported by extensions of {@link HttpServiceClientRegistrarSupport}.
+ *
+ * @author Rossen Stoyanchev
+ * @since 7.0
+ * @see HttpServiceClientRegistrarSupport
+ */
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+public @interface HttpServiceClient {
+
+	/**
+	 * An alias for {@link #group()}.
+	 */
+	@AliasFor("group")
+	String value() default HttpServiceGroup.DEFAULT_GROUP_NAME;
+
+	/**
+	 * The name of the HTTP Service group for this client.
+	 * <p>By default, this is {@link HttpServiceGroup#DEFAULT_GROUP_NAME}.
+	 */
+	@AliasFor("value")
+	String group() default HttpServiceGroup.DEFAULT_GROUP_NAME;
+
+}

spring-web/src/main/java/org/springframework/web/service/registry/HttpServiceClientRegistrarSupport.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2002-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.service.registry;
+
+
+import java.util.List;
+
+import org.springframework.beans.factory.annotation.AnnotatedBeanDefinition;
+import org.springframework.core.annotation.MergedAnnotations;
+import org.springframework.core.type.AnnotationMetadata;
+
+/**
+ * Base class for an {@link AbstractHttpServiceRegistrar} to detects and register
+ * {@link HttpServiceClient @HttpServiceClient} annotated interfaces.
+ *
+ * <p>Subclasses need to implement
+ * {@link #registerHttpServices(GroupRegistry, AnnotationMetadata)} and invoke
+ * {@link #findAndRegisterHttpServiceClients(GroupRegistry, List)}.
+ *
+ * @author Rossen Stoyanchev
+ * @since 7.0
+ */
+public abstract class HttpServiceClientRegistrarSupport extends AbstractHttpServiceRegistrar {
+
+	/**
+	 * Find all HTTP Services under the given base packages that also have an
+	 * {@link HttpServiceClient @HttpServiceClient} annotation, and register them
+	 * in the group specified on the annotation.
+	 * @param registry the registry from {@link #registerHttpServices(GroupRegistry, AnnotationMetadata)}
+	 * @param basePackages the base packages to scan
+	 */
+	protected void findAndRegisterHttpServiceClients(GroupRegistry registry, List<String> basePackages) {
+		basePackages.stream()
+				.flatMap(this::findHttpServices)
+				.filter(definition -> definition instanceof AnnotatedBeanDefinition)
+				.map(definition -> (AnnotatedBeanDefinition) definition)
+				.filter(definition -> definition.getMetadata().hasAnnotation(HttpServiceClient.class.getName()))
+				.filter(definition -> definition.getBeanClassName() != null)
+				.forEach(definition -> {
+					MergedAnnotations annotations = definition.getMetadata().getAnnotations();
+					String group = annotations.get(HttpServiceClient.class).getString("group");
+					registry.forGroup(group).registerTypeNames(definition.getBeanClassName());
+				});
+	}
+
+}

spring-web/src/test/java/org/springframework/web/service/registry/HttpServiceClientRegistrarSupportTests.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2002-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.service.registry;
+
+
+import java.util.List;
+import java.util.Map;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.core.env.StandardEnvironment;
+import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
+import org.springframework.core.type.AnnotationMetadata;
+import org.springframework.web.service.registry.client.DefaultClient;
+import org.springframework.web.service.registry.client.EchoClientA;
+import org.springframework.web.service.registry.client.EchoClientB;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Unit tests for {@link HttpServiceClientRegistrarSupport}.
+ * @author Rossen Stoyanchev
+ */
+public class HttpServiceClientRegistrarSupportTests {
+
+	private final TestGroupRegistry groupRegistry = new TestGroupRegistry();
+
+
+	@Test
+	void register() {
+		HttpServiceClientRegistrarSupport registrar = new HttpServiceClientRegistrarSupport() {
+
+			@Override
+			protected void registerHttpServices(GroupRegistry registry, AnnotationMetadata importingClassMetadata) {
+				findAndRegisterHttpServiceClients(groupRegistry, List.of(getClass().getPackage().getName() + ".client"));
+			}
+		};
+		registrar.setEnvironment(new StandardEnvironment());
+		registrar.setResourceLoader(new PathMatchingResourcePatternResolver());
+
+		registrar.registerHttpServices(groupRegistry, mock(AnnotationMetadata.class));
+
+		assertGroups(
+				TestGroup.ofListing("echo", EchoClientA.class, EchoClientB.class),
+				TestGroup.ofListing("default", DefaultClient.class));
+	}
+
+	private void assertGroups(TestGroup... expectedGroups) {
+		Map<String, TestGroup> groupMap = this.groupRegistry.groupMap();
+		assertThat(groupMap.size()).isEqualTo(expectedGroups.length);
+		for (TestGroup expected : expectedGroups) {
+			TestGroup actual = groupMap.get(expected.name());
+			assertThat(actual.httpServiceTypes()).isEqualTo(expected.httpServiceTypes());
+			assertThat(actual.clientType()).isEqualTo(expected.clientType());
+			assertThat(actual.packageNames()).isEqualTo(expected.packageNames());
+			assertThat(actual.packageClasses()).isEqualTo(expected.packageClasses());
+		}
+	}
+
+}

spring-web/src/test/java/org/springframework/web/service/registry/client/DefaultClient.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2002-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.service.registry.client;
+
+
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.service.annotation.GetExchange;
+import org.springframework.web.service.registry.HttpServiceClient;
+
+@HttpServiceClient
+public interface DefaultClient {
+
+	@GetExchange
+	String handle(@RequestParam String input);
+
+}

spring-web/src/test/java/org/springframework/web/service/registry/client/EchoClientA.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2002-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.service.registry.client;
+
+
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.service.annotation.GetExchange;
+import org.springframework.web.service.registry.HttpServiceClient;
+
+@HttpServiceClient("echo")
+public interface EchoClientA {
+
+	@GetExchange
+	String handle(@RequestParam String input);
+
+}

spring-web/src/test/java/org/springframework/web/service/registry/client/EchoClientB.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2002-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.service.registry.client;
+
+
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.service.annotation.GetExchange;
+import org.springframework.web.service.registry.HttpServiceClient;
+
+@HttpServiceClient("echo")
+public interface EchoClientB {
+
+	@GetExchange
+	String handle(@RequestParam String input);
+
+}