Add support for spring.cloud.function.scan.packages in functional

Fixes gh-372

spring-cloud-function-context/src/main/java/org/springframework/cloud/function/context/config/ContextFunctionCatalogInitializer.java

@@ -16,12 +16,17 @@
 
 package org.springframework.cloud.function.context.config;
 
+import java.util.function.Consumer;
+import java.util.function.Function;
+import java.util.function.Supplier;
+
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.google.gson.Gson;
 
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.BeanCreationException;
 import org.springframework.beans.factory.ObjectProvider;
+import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.config.BeanPostProcessor;
 import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
@@ -36,9 +41,12 @@ import org.springframework.cloud.function.context.catalog.InMemoryFunctionCatalo
 import org.springframework.cloud.function.json.JsonMapper;
 import org.springframework.context.ApplicationContextInitializer;
 import org.springframework.context.annotation.AnnotationConfigUtils;
+import org.springframework.context.annotation.ClassPathBeanDefinitionScanner;
 import org.springframework.context.support.GenericApplicationContext;
 import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
+import org.springframework.core.io.ClassPathResource;
 import org.springframework.core.type.classreading.MetadataReaderFactory;
+import org.springframework.core.type.filter.AssignableTypeFilter;
 import org.springframework.format.support.DefaultFormattingConversionService;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
@@ -155,6 +163,26 @@ public class ContextFunctionCatalogInitializer
 
 			}
 
+			String basePackage = this.context.getEnvironment()
+					.getProperty("spring.cloud.function.scan.packages", "functions");
+			if (new ClassPathResource(basePackage.replace(".", "/")).exists()) {
+				ClassPathBeanDefinitionScanner scanner = new ClassPathBeanDefinitionScanner(
+						this.context, false, this.context.getEnvironment(), this.context);
+				scanner.addIncludeFilter(new AssignableTypeFilter(Function.class));
+				scanner.addIncludeFilter(new AssignableTypeFilter(Supplier.class));
+				scanner.addIncludeFilter(new AssignableTypeFilter(Consumer.class));
+				for (BeanDefinition bean : scanner.findCandidateComponents(basePackage)) {
+					String name = bean.getBeanClassName();
+					Class<?> type = ClassUtils.resolveClassName(name,
+							this.context.getClassLoader());
+					this.context.registerBeanDefinition(name, bean);
+					this.context.registerBean("registration_" + name,
+							FunctionRegistration.class,
+							() -> new FunctionRegistration<>(this.context.getBean(name),
+									name).type(type));
+				}
+			}
+
 			if (this.context.getBeanFactory().getBeanNamesForType(FunctionCatalog.class,
 					false, false).length == 0) {
 				this.context.registerBean(InMemoryFunctionCatalog.class,

spring-cloud-function-context/src/test/java/org/springframework/cloud/function/context/config/ContextFunctionCatalogInitializerTests.java

@@ -40,6 +40,7 @@ import org.springframework.cloud.function.context.FunctionCatalog;
 import org.springframework.cloud.function.context.FunctionRegistration;
 import org.springframework.cloud.function.context.FunctionType;
 import org.springframework.cloud.function.context.catalog.FunctionInspector;
+import org.springframework.cloud.function.context.scan.TestFunction;
 import org.springframework.context.ApplicationContextInitializer;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.support.GenericApplicationContext;
@@ -162,8 +163,23 @@ public class ContextFunctionCatalogInitializerTests {
 		assertThat(function.apply(Flux.just("foo")).blockFirst()).isEqualTo("FOO");
 		assertThat(bean).isNotSameAs(function);
 		assertThat(this.inspector.getRegistration(function)).isNotNull();
-		assertThat(this.inspector.getRegistration(function).getType()).isEqualTo(
-				FunctionType.from(String.class).to(String.class));
+		assertThat(this.inspector.getRegistration(function).getType())
+				.isEqualTo(FunctionType.from(String.class).to(String.class));
+	}
+
+	@Test
+	public void scanFunction() {
+		create(EmptyConfiguration.class,
+				"spring.cloud.function.scan.packages=org.springframework.cloud.function.context.scan");
+		Object bean = this.context.getBean(TestFunction.class.getName());
+		assertThat(bean).isInstanceOf(Function.class);
+		Function<Flux<String>, Flux<String>> function = this.catalog
+				.lookup(Function.class, TestFunction.class.getName());
+		assertThat(function.apply(Flux.just("foo")).blockFirst()).isEqualTo("FOO");
+		assertThat(bean).isNotSameAs(function);
+		assertThat(this.inspector.getRegistration(function)).isNotNull();
+		assertThat(this.inspector.getRegistration(function).getType())
+				.isEqualTo(FunctionType.from(String.class).to(String.class));
 	}
 
 	@Test

spring-cloud-function-context/src/test/java/org/springframework/cloud/function/context/scan/TestFunction.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2019-2019 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.cloud.function.context.scan;
+
+import java.util.function.Function;
+
+/**
+ * @author Dave Syer
+ *
+ */
+public class TestFunction implements Function<String, String> {
+
+	@Override
+	public String apply(String t) {
+		return t.toUpperCase();
+	}
+
+}