Added support for input Collection param

Added support for function parameter type Collection
Updated both Jackson and Gson mappers
Defined a new toObject() operation on JsonMapper and deprecated the old

Resolves #210

spring-cloud-function-context/src/main/java/org/springframework/cloud/function/json/GsonMapper.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2017 the original author or authors.
+ * Copyright 2016-2018 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.
@@ -15,16 +15,13 @@
  */
 package org.springframework.cloud.function.json;
 
-import java.util.ArrayList;
-import java.util.List;
+import java.lang.reflect.Type;
 
 import com.google.gson.Gson;
 
-import org.springframework.cloud.function.json.JsonMapper;
-import org.springframework.core.ResolvableType;
-
 /**
  * @author Dave Syer
+ * @author Oleg Zhurakousky
  *
  */
 public class GsonMapper implements JsonMapper {
@@ -36,13 +33,7 @@ public class GsonMapper implements JsonMapper {
 	}
 
 	@Override
-	public <T> List<T> toList(String json, Class<T> type) {
-		return gson.fromJson(json,
-				ResolvableType.forClassWithGenerics(ArrayList.class, type).getType());
-	}
-
-	@Override
-	public <T> T toSingle(String json, Class<T> type) {
+	public <T> T toObject(String json, Type type) {
 		return gson.fromJson(json, type);
 	}
 

spring-cloud-function-context/src/main/java/org/springframework/cloud/function/json/JacksonMapper.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2017 the original author or authors.
+ * Copyright 2016-2018 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.
@@ -15,17 +15,15 @@
  */
 package org.springframework.cloud.function.json;
 
-import java.util.ArrayList;
-import java.util.List;
+import java.lang.reflect.Type;
 
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
-
-import org.springframework.cloud.function.json.JsonMapper;
+import com.fasterxml.jackson.databind.type.TypeFactory;
 
 /**
  * @author Dave Syer
- *
+ * @author Oleg Zhurakousky
  */
 public class JacksonMapper implements JsonMapper {
 
@@ -36,23 +34,12 @@ public class JacksonMapper implements JsonMapper {
 	}
 
 	@Override
-	public <T> List<T> toList(String json, Class<T> type) {
+	public <T> T toObject(String json, Type type) {
 		try {
-			return mapper.readValue(json, mapper.getTypeFactory()
-					.constructCollectionLikeType(ArrayList.class, type));
+			return mapper.readValue(json, TypeFactory.defaultInstance().constructType(type));
 		}
 		catch (Exception e) {
-			throw new IllegalArgumentException("Cannot convert JSON", e);
-		}
-	}
-
-	@Override
-	public <T> T toSingle(String json, Class<T> type) {
-		try {
-			return mapper.readValue(json, type);
-		}
-		catch (Exception e) {
-			throw new IllegalArgumentException("Cannot convert JSON", e);
+			throw new IllegalArgumentException("Cannot convert JSON " + json, e);
 		}
 	}
 

spring-cloud-function-context/src/main/java/org/springframework/cloud/function/json/JsonMapper.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2017 the original author or authors.
+ * Copyright 2016-2018 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.
@@ -15,17 +15,41 @@
  */
 package org.springframework.cloud.function.json;
 
+import java.lang.reflect.Type;
+import java.util.ArrayList;
 import java.util.List;
 
+import org.springframework.core.ResolvableType;
+
 /**
  * @author Dave Syer
- *
+ * @author Oleg Zhurakousky
  */
 public interface JsonMapper {
 
-	<T> List<T> toList(String json, Class<T> type);
+	/**
+	 * @deprecated in favor of {@link #toObject(String, Type)}
+	 */
+	@Deprecated
+	default <T> List<T> toList(String json, Class<T> type) {
+		Type actualType = (json.startsWith("[") && !List.class.isAssignableFrom(type))
+				? ResolvableType.forClassWithGenerics(ArrayList.class, (Class<?>) type)
+						.getType()
+				: type;
+		return toObject(json, actualType);
+	}
 
-	<T> T toSingle(String json, Class<T> type);
+	/**
+	 * @since 2.0
+	 */
+	<T> T toObject(String json, Type type);
+
+	/**
+	 * @deprecated in favor of {@link #toObject(String, Type)}
+	 */
+	default <T> T toSingle(String json, Class<T> type) {
+		return toObject(json, type);
+	}
 
 	String toString(Object value);
 

spring-cloud-function-context/src/test/java/org/springframework/cloud/function/util/JsonMapperTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2017 the original author or authors.
+ * Copyright 2016-2018 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.
@@ -29,11 +29,13 @@ import org.junit.runners.Parameterized.Parameters;
 import org.springframework.cloud.function.json.GsonMapper;
 import org.springframework.cloud.function.json.JacksonMapper;
 import org.springframework.cloud.function.json.JsonMapper;
+import org.springframework.core.ResolvableType;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
  * @author Dave Syer
+ * @author Oleg Zhurakousky
  *
  */
 @RunWith(Parameterized.class)
@@ -54,8 +56,8 @@ public class JsonMapperTests {
 	@Test
 	public void vanillaArray() {
 		String json = "[{\"value\":\"foo\"},{\"value\":\"foo\"}]";
-		List<Foo> list = mapper.toList(json,
-				Foo.class);
+		List<Foo> list = mapper.toObject(json,
+				ResolvableType.forClassWithGenerics(List.class, Foo.class).getType());
 		assertThat(list).hasSize(2);
 		assertThat(list.get(0).getValue()).isEqualTo("foo");
 		assertThat(mapper.toString(list)).isEqualTo(json);
@@ -63,34 +65,36 @@ public class JsonMapperTests {
 
 	@Test
 	public void intArray() {
-		List<Integer> list = mapper.toList("[123,456]", Integer.class);
+		List<Integer> list = mapper.toObject("[123,456]",
+				ResolvableType.forClassWithGenerics(List.class, Integer.class).getType());
 		assertThat(list).hasSize(2);
 		assertThat(list.get(0)).isEqualTo(123);
 	}
 
 	@Test
 	public void emptyArray() {
-		List<Foo> list = mapper.toList("[]", Foo.class);
+		List<Foo> list = mapper.toObject("[]",
+				ResolvableType.forClassWithGenerics(List.class, Foo.class).getType());
 		assertThat(list).hasSize(0);
 	}
 
 	@Test
 	public void vanillaObject() {
 		String json = "{\"value\":\"foo\"}";
-		Foo foo = mapper.toSingle(json, Foo.class);
+		Foo foo = mapper.toObject(json, Foo.class);
 		assertThat(foo.getValue()).isEqualTo("foo");
 		assertThat(mapper.toString(foo)).isEqualTo(json);
 	}
 
 	@Test
 	public void intValue() {
-		int foo = mapper.toSingle("123", Integer.class);
+		int foo = mapper.toObject("123", Integer.class);
 		assertThat(foo).isEqualTo(123);
 	}
 
 	@Test
 	public void empty() {
-		Foo foo = mapper.toSingle("{}", Foo.class);
+		Foo foo = mapper.toObject("{}", Foo.class);
 		assertThat(foo.getValue()).isNull();
 	}
 

spring-cloud-function-web/src/main/java/org/springframework/cloud/function/web/RequestProcessor.java

@@ -16,6 +16,7 @@
 
 package org.springframework.cloud.function.web;
 
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
@@ -36,6 +37,7 @@ import org.springframework.cloud.function.context.message.MessageUtils;
 import org.springframework.cloud.function.core.FluxWrapper;
 import org.springframework.cloud.function.json.JsonMapper;
 import org.springframework.cloud.function.web.util.HeaderUtils;
+import org.springframework.core.ResolvableType;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
@@ -72,12 +74,15 @@ public class RequestProcessor {
 		this.converter = converter;
 	}
 
-	public static FunctionWrapper wrapper(Function<? extends Publisher<?>, ? extends Publisher<?>> function,
-			Consumer<? extends Publisher<?>> consumer, Supplier<? extends Publisher<?>> supplier) {
+	public static FunctionWrapper wrapper(
+			Function<? extends Publisher<?>, ? extends Publisher<?>> function,
+			Consumer<? extends Publisher<?>> consumer,
+			Supplier<? extends Publisher<?>> supplier) {
 		return new FunctionWrapper(function, consumer, supplier);
 	}
 
-	public static FunctionWrapper wrapper(Function<? extends Publisher<?>, ? extends Publisher<?>> function) {
+	public static FunctionWrapper wrapper(
+			Function<? extends Publisher<?>, ? extends Publisher<?>> function) {
 		return new FunctionWrapper(function, null, null);
 	}
 
@@ -94,21 +99,24 @@ public class RequestProcessor {
 
 	public Mono<ResponseEntity<?>> post(FunctionWrapper wrapper, String body,
 			boolean stream) {
-		Mono<ResponseEntity<?>> responseEntityMono;
 		Object function = wrapper.handler();
+		Class<?> inputType = inspector.getInputType(function);
 
 		Object input = null;
 		if (StringUtils.hasText(body)) {
-			Class<?> inputType = inspector.getInputType(function);
 			if (body.startsWith("[")) {
-				input = mapper.toList(body, inputType);
+				input = Collection.class.isAssignableFrom(inputType)
+						? mapper.toObject(body, inputType)
+						: mapper.toObject(body, ResolvableType
+								.forClassWithGenerics(ArrayList.class, (Class<?>) inputType)
+								.getType());
 			}
 			else {
 				if (inputType == String.class) {
 					input = body;
 				}
 				else if (body.startsWith("{")) {
-					input = mapper.toSingle(body, inputType);
+					input = mapper.toObject(body, inputType);
 				}
 				else if (body.startsWith("\"")) {
 					input = body.substring(1, body.length() - 2);
@@ -118,8 +126,8 @@ public class RequestProcessor {
 				}
 			}
 		}
-		responseEntityMono = post(wrapper, input, null, stream);
-		return responseEntityMono;
+		return post(wrapper, input, null, stream,
+				!Collection.class.isAssignableFrom(inputType));
 	}
 
 	public Mono<ResponseEntity<?>> stream(FunctionWrapper request) {
@@ -130,7 +138,8 @@ public class RequestProcessor {
 	}
 
 	private Mono<ResponseEntity<?>> post(FunctionWrapper wrapper, Object body,
-			MultiValueMap<String, String> params, boolean stream) {
+			MultiValueMap<String, String> params, boolean stream,
+			boolean shouldFluxAsIterable) {
 
 		Iterable<?> iterable = body instanceof Collection ? (List<?>) body
 				: Collections.singletonList(body);
@@ -143,7 +152,8 @@ public class RequestProcessor {
 			form.putAll(params);
 		}
 
-		Flux<?> flux = body == null ? Flux.just(form) : Flux.fromIterable(iterable);
+		Flux<?> flux = body == null ? Flux.just(form)
+				: shouldFluxAsIterable ? Flux.fromIterable(iterable) : Flux.just(body);
 		if (inspector.isMessage(function)) {
 			flux = messages(wrapper, function == null ? consumer : function, flux);
 		}
@@ -239,7 +249,8 @@ public class RequestProcessor {
 		}
 	}
 
-	private Publisher<?> value(Function<Publisher<?>, Publisher<?>> function, Publisher<String> value) {
+	private Publisher<?> value(Function<Publisher<?>, Publisher<?>> function,
+			Publisher<String> value) {
 		Flux<?> input = Flux.from(value).map(body -> converter.convert(function, body));
 		return Mono.from(function.apply(input));
 	}
@@ -259,8 +270,10 @@ public class RequestProcessor {
 		private Publisher<String> argument;
 
 		@SuppressWarnings("unchecked")
-		public FunctionWrapper(Function<? extends Publisher<?>, ? extends Publisher<?>> function,
-				Consumer<? extends Publisher<?>> consumer, Supplier<? extends Publisher<?>> supplier) {
+		public FunctionWrapper(
+				Function<? extends Publisher<?>, ? extends Publisher<?>> function,
+				Consumer<? extends Publisher<?>> consumer,
+				Supplier<? extends Publisher<?>> supplier) {
 			this.function = (Function<Publisher<?>, Publisher<?>>) function;
 			this.consumer = (Consumer<Publisher<?>>) consumer;
 			this.supplier = (Supplier<Publisher<?>>) supplier;

spring-cloud-function-web/src/test/java/org/springframework/cloud/function/test/FunctionalWithInputCollectionTests.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2012-2015 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
+ *
+ *      http://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.test;
+
+import java.util.List;
+import java.util.function.Function;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.SpringBootConfiguration;
+import org.springframework.boot.test.autoconfigure.web.reactive.AutoConfigureWebTestClient;
+import org.springframework.cloud.function.context.test.FunctionalSpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.test.web.reactive.server.WebTestClient;
+
+import reactor.core.publisher.Mono;
+
+/**
+ * @author Dave Syer
+ *
+ */
+@RunWith(SpringRunner.class)
+@FunctionalSpringBootTest("spring.main.web-application-type=reactive")
+@AutoConfigureWebTestClient
+public class FunctionalWithInputCollectionTests {
+
+	@Autowired
+	private WebTestClient client;
+
+	@Test
+	public void words() throws Exception {
+		client.post().uri("/").body(Mono.just("[\"foo\", \"bar\"]"), String.class).exchange()
+				.expectStatus().isOk().expectBody(String.class).isEqualTo("[FOO, BAR]");
+	}
+
+	@SpringBootConfiguration
+	protected static class TestConfiguration implements Function<List<String>, String> {
+		@Override
+		public String apply(List<String> value) {
+			return value.toString().toUpperCase();
+		}
+	}
+}