Make CloudEventAttributesProvider a FunctionalInterface

Related to #422 and #606

spring-cloud-function-context/src/main/java/org/springframework/cloud/function/cloudevent/CloudEventAttributesProvider.java

@@ -19,48 +19,14 @@ package org.springframework.cloud.function.cloudevent;
 import java.util.Map;
 
 import org.springframework.messaging.Message;
-import org.springframework.messaging.MessageHeaders;
 
 /**
  *
  * @author Oleg Zhurakousky
  * @since 3.1
  */
+@FunctionalInterface
 public interface CloudEventAttributesProvider {
-
-	/**
-	 * Will construct instance of {@link CloudEventAttributes} setting its required attributes.
-	 *
-	 * @param ce_id value for Cloud Event 'id' attribute
-	 * @param ce_specversion value for Cloud Event 'specversion' attribute
-	 * @param ce_source value for Cloud Event 'source' attribute
-	 * @param ce_type value for Cloud Event 'type' attribute
-	 * @return instance of {@link CloudEventAttributes}
-	 */
-	CloudEventAttributes get(String ce_id, String ce_specversion, String ce_source, String ce_type);
-
-	/**
-	 * Will construct instance of {@link CloudEventAttributes}
-	 * Should default/generate cloud event ID and SPECVERSION.
-	 *
-	 * @param ce_source value for Cloud Event 'source' attribute
-	 * @param ce_type value for Cloud Event 'type' attribute
-	 * @return instance of {@link CloudEventAttributes}
-	 */
-	CloudEventAttributes get(String ce_source, String ce_type);
-
-
-	/**
-	 * Will construct instance of {@link CloudEventAttributes} from {@link MessageHeaders}.
-	 *
-	 * Should copy Cloud Event related headers into an instance of {@link CloudEventAttributes}
-	 * NOTE: Certain headers must not be copied.
-	 *
-	 * @param headers instance of {@link MessageHeaders}
-	 * @return modifiable instance of {@link CloudEventAttributes}
-	 */
-	RequiredAttributeAccessor get(MessageHeaders headers);
-
 	/**
 	 *
 	 * @param inputMessage input message used to invoke user functionality (e.g., function)

spring-cloud-function-context/src/main/java/org/springframework/cloud/function/cloudevent/CloudEventMessageUtils.java

@@ -16,9 +16,13 @@
 
 package org.springframework.cloud.function.cloudevent;
 
+import java.util.HashMap;
 import java.util.Map;
+import java.util.UUID;
 
 import org.springframework.messaging.Message;
+import org.springframework.messaging.MessageHeaders;
+import org.springframework.util.Assert;
 import org.springframework.util.MimeType;
 import org.springframework.util.MimeTypeUtils;
 
@@ -155,4 +159,52 @@ public final class CloudEventMessageUtils {
 				&& headers.containsKey(CE_SPECVERSION)
 				&& headers.containsKey(CE_TYPE));
 	}
+
+
+	/**
+	 * Will construct instance of {@link CloudEventAttributes} setting its required attributes.
+	 *
+	 * @param ce_id value for Cloud Event 'id' attribute
+	 * @param ce_specversion value for Cloud Event 'specversion' attribute
+	 * @param ce_source value for Cloud Event 'source' attribute
+	 * @param ce_type value for Cloud Event 'type' attribute
+	 * @return instance of {@link CloudEventAttributes}
+	 */
+	public static CloudEventAttributes get(String ce_id, String ce_specversion, String ce_source, String ce_type) {
+		Assert.hasText(ce_id, "'ce_id' must not be null or empty");
+		Assert.hasText(ce_specversion, "'ce_specversion' must not be null or empty");
+		Assert.hasText(ce_source, "'ce_source' must not be null or empty");
+		Assert.hasText(ce_type, "'ce_type' must not be null or empty");
+		Map<String, Object> requiredAttributes = new HashMap<>();
+		requiredAttributes.put(CloudEventMessageUtils.CE_ID, ce_id);
+		requiredAttributes.put(CloudEventMessageUtils.CE_SPECVERSION, ce_specversion);
+		requiredAttributes.put(CloudEventMessageUtils.CE_SOURCE, ce_source);
+		requiredAttributes.put(CloudEventMessageUtils.CE_TYPE, ce_type);
+		return new CloudEventAttributes(requiredAttributes);
+	}
+
+	/**
+	 * Will construct instance of {@link CloudEventAttributes}
+	 * Should default/generate cloud event ID and SPECVERSION.
+	 *
+	 * @param ce_source value for Cloud Event 'source' attribute
+	 * @param ce_type value for Cloud Event 'type' attribute
+	 * @return instance of {@link CloudEventAttributes}
+	 */
+	public static CloudEventAttributes get(String ce_source, String ce_type) {
+		return get(UUID.randomUUID().toString(), "1.0", ce_source, ce_type);
+	}
+
+	/**
+	 * Will construct instance of {@link CloudEventAttributes} from {@link MessageHeaders}.
+	 *
+	 * Should copy Cloud Event related headers into an instance of {@link CloudEventAttributes}
+	 * NOTE: Certain headers must not be copied.
+	 *
+	 * @param headers instance of {@link MessageHeaders}
+	 * @return modifiable instance of {@link CloudEventAttributes}
+	 */
+	public static RequiredAttributeAccessor get(MessageHeaders headers) {
+		return new RequiredAttributeAccessor(headers);
+	}
 }

spring-cloud-function-context/src/main/java/org/springframework/cloud/function/cloudevent/DefaultCloudEventAttributesProvider.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2019 the original author or authors.
+ * Copyright 2020-2020 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.
@@ -17,7 +17,6 @@
 package org.springframework.cloud.function.cloudevent;
 
 import java.util.Collections;
-import java.util.HashMap;
 import java.util.Map;
 import java.util.UUID;
 
@@ -27,8 +26,6 @@ import org.springframework.context.ApplicationContextAware;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.core.env.ConfigurableEnvironment;
 import org.springframework.messaging.Message;
-import org.springframework.messaging.MessageHeaders;
-import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
 /**
@@ -41,38 +38,12 @@ public class DefaultCloudEventAttributesProvider implements CloudEventAttributes
 
 	private ConfigurableApplicationContext applicationContext;
 
-	@Override
-	public CloudEventAttributes get(String ce_id, String ce_specversion, String ce_source, String ce_type) {
-		Assert.hasText(ce_id, "'ce_id' must not be null or empty");
-		Assert.hasText(ce_specversion, "'ce_specversion' must not be null or empty");
-		Assert.hasText(ce_source, "'ce_source' must not be null or empty");
-		Assert.hasText(ce_type, "'ce_type' must not be null or empty");
-		Map<String, Object> requiredAttributes = new HashMap<>();
-		requiredAttributes.put(CloudEventMessageUtils.CE_ID, ce_id);
-		requiredAttributes.put(CloudEventMessageUtils.CE_SPECVERSION, ce_specversion);
-		requiredAttributes.put(CloudEventMessageUtils.CE_SOURCE, ce_source);
-		requiredAttributes.put(CloudEventMessageUtils.CE_TYPE, ce_type);
-		return new CloudEventAttributes(requiredAttributes);
-	}
-
-	@Override
-	public CloudEventAttributes get(String ce_source, String ce_type) {
-		return this.get(UUID.randomUUID().toString(), "1.0", ce_source, ce_type);
-	}
-
-	/**
-	 * By default it will copy all the headers while exposing accessor to allow user to modify any of them.
-	 */
-	@Override
-	public RequiredAttributeAccessor get(MessageHeaders headers) {
-		return new RequiredAttributeAccessor(headers);
-	}
 
 	@Override
 	public Map<String, Object> generateDefaultCloudEventHeaders(Message<?> inputMessage, Object result) {
 		if (inputMessage.getHeaders().containsKey(CloudEventMessageUtils.CE_ID)) { // input is a cloud event
 			String applicationName = this.getApplicationName();
-			return this.get(inputMessage.getHeaders())
+			return CloudEventMessageUtils.get(inputMessage.getHeaders())
 					.setId(UUID.randomUUID().toString())
 					.setType(result.getClass().getName())
 					.setSource(applicationName);

spring-cloud-function-context/src/test/java/org/springframework/cloud/function/cloudevent/CloudEventTypeConversionTests.java

@@ -45,8 +45,7 @@ public class CloudEventTypeConversionTests {
 	@Test
 	public void testFromMessageBinaryPayloadMatchesType() {
 		SmartCompositeMessageConverter messageConverter = this.configure(DummyConfiguration.class);
-		CloudEventAttributesProvider ceAttrProvider = new DefaultCloudEventAttributesProvider();
+		CloudEventAttributes ceAttributes = CloudEventMessageUtils
-		CloudEventAttributes ceAttributes = ceAttrProvider
 				.get(UUID.randomUUID().toString(), "1.0", "https://spring.io/", "org.springframework");
 		ceAttributes.setDataContentType("text/plain");
 		Message<String> message = MessageBuilder.withPayload("Hello Ricky").copyHeaders(ceAttributes).build();
@@ -58,8 +57,7 @@ public class CloudEventTypeConversionTests {
 	@Test
 	public void testFromMessageBinaryPayloadDoesNotMatchType() {
 		SmartCompositeMessageConverter messageConverter = this.configure(DummyConfiguration.class);
-		CloudEventAttributesProvider ceAttrProvider = new DefaultCloudEventAttributesProvider();
+		CloudEventAttributes ceAttributes = CloudEventMessageUtils
-		CloudEventAttributes ceAttributes = ceAttrProvider
 				.get(UUID.randomUUID().toString(), "1.0", "https://spring.io/", "org.springframework");
 		Message<byte[]> message = MessageBuilder.withPayload("Hello Ricky".getBytes())
 				.copyHeaders(ceAttributes)
@@ -70,12 +68,10 @@ public class CloudEventTypeConversionTests {
 		assertThat(converted).isEqualTo("Hello Ricky");
 	}
 
-	@Test // JsonMessageConverter does some special things between byte[] and String so
+	@Test // JsonMessageConverter does some special things between byte[] and String so this works
-			// this works
 	public void testFromMessageBinaryPayloadNoDataContentTypeToString() {
 		SmartCompositeMessageConverter messageConverter = this.configure(DummyConfiguration.class);
-		CloudEventAttributesProvider ceAttrProvider = new DefaultCloudEventAttributesProvider();
+		CloudEventAttributes ceAttributes = CloudEventMessageUtils
-		CloudEventAttributes ceAttributes = ceAttrProvider
 				.get(UUID.randomUUID().toString(), "1.0", "https://spring.io/", "org.springframework");
 		Message<byte[]> message = MessageBuilder.withPayload("Hello Ricky".getBytes())
 				.copyHeaders(ceAttributes)
@@ -89,8 +85,7 @@ public class CloudEventTypeConversionTests {
 	@Test // Unlike the previous test the type here is POJO so no special treatement
 	public void testFromMessageBinaryPayloadNoDataContentTypeToPOJO() {
 		SmartCompositeMessageConverter messageConverter = this.configure(DummyConfiguration.class);
-		CloudEventAttributesProvider ceAttrProvider = new DefaultCloudEventAttributesProvider();
+		CloudEventAttributes ceAttributes = CloudEventMessageUtils.get("https://spring.io/", "org.springframework");
-		CloudEventAttributes ceAttributes = ceAttrProvider.get("https://spring.io/", "org.springframework");
 		Message<byte[]> message = MessageBuilder.withPayload("Hello Ricky".getBytes())
 				.copyHeaders(ceAttributes)
 				.setHeader(MessageHeaders.CONTENT_TYPE,
@@ -103,8 +98,7 @@ public class CloudEventTypeConversionTests {
 	@Test // will fall on default CT which is json
 	public void testFromMessageBinaryPayloadNoDataContentTypeToPOJOThatWorks() {
 		SmartCompositeMessageConverter messageConverter = this.configure(DummyConfiguration.class);
-		CloudEventAttributesProvider ceAttrProvider = new DefaultCloudEventAttributesProvider();
+		CloudEventAttributes ceAttributes = CloudEventMessageUtils.get("https://spring.io/", "org.springframework");
-		CloudEventAttributes ceAttributes = ceAttrProvider.get("https://spring.io/", "org.springframework");
 		Message<byte[]> message = MessageBuilder.withPayload("{\"name\":\"Ricky\"}".getBytes())
 				.copyHeaders(ceAttributes)
 				.setHeader(MessageHeaders.CONTENT_TYPE,

spring-cloud-function-samples/function-sample-cloudevent/src/main/java/io/spring/cloudevent/CloudeventDemoApplication.java

@@ -16,11 +16,7 @@
 
 package io.spring.cloudevent;
 
-import java.text.ParseException;
-import java.text.SimpleDateFormat;
-import java.util.Collections;
 import java.util.Map;
-import java.util.UUID;
 import java.util.function.Function;
 
 import org.springframework.boot.SpringApplication;
@@ -28,8 +24,6 @@ import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.cloud.function.cloudevent.CloudEventAttributes;
 import org.springframework.cloud.function.cloudevent.CloudEventAttributesProvider;
 import org.springframework.cloud.function.cloudevent.CloudEventMessageUtils;
-import org.springframework.cloud.function.cloudevent.DefaultCloudEventAttributesProvider;
-import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.messaging.Message;
 import org.springframework.messaging.support.MessageBuilder;
@@ -96,7 +90,7 @@ public class CloudeventDemoApplication {
 			data.setVersion("2.0");
 			data.setReleaseDateAsString("01-10-2006");
 
-			CloudEventAttributes ceAttributes = ceAttrProvider.get(ceMessage.getHeaders())
+			CloudEventAttributes ceAttributes = CloudEventMessageUtils.get(ceMessage.getHeaders())
 				.setSource("https://interface21.com/")
 				.setType("com.interface21");
 

spring-cloud-function-samples/function-sample-cloudevent/src/test/java/io/spring/cloudevent/CloudeventDemoApplicationFunctionTests.java

@@ -20,8 +20,7 @@ import java.util.function.Function;
 
 import org.junit.jupiter.api.Test;
 import org.springframework.boot.SpringApplication;
-import org.springframework.cloud.function.cloudevent.CloudEventAttributesProvider;
+import org.springframework.cloud.function.cloudevent.CloudEventMessageUtils;
-import org.springframework.cloud.function.cloudevent.DefaultCloudEventAttributesProvider;
 import org.springframework.cloud.function.context.FunctionCatalog;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.messaging.Message;
@@ -39,10 +38,9 @@ public class CloudeventDemoApplicationFunctionTests {
 
 		try(ConfigurableApplicationContext context = SpringApplication.run(CloudeventDemoApplication.class)) {
 			FunctionCatalog catalog = context.getBean(FunctionCatalog.class);
-			CloudEventAttributesProvider ceAttrProvider = new DefaultCloudEventAttributesProvider();
 			Message<String> binaryCloudEventMessage = MessageBuilder
 					.withPayload("{\"releaseDate\":\"24-03-2004\", \"releaseName\":\"Spring Framework\", \"version\":\"1.0\"}")
-					.copyHeaders(ceAttrProvider.get("spring.io/spring-event", "com.example.springevent"))
+					.copyHeaders(CloudEventMessageUtils.get("spring.io/spring-event", "com.example.springevent"))
 					.build();
 
 			/*
@@ -68,10 +66,9 @@ public class CloudeventDemoApplicationFunctionTests {
 	public void demoPureFunctionProduceConsumeCloudEvent() {
 		try(ConfigurableApplicationContext context = SpringApplication.run(CloudeventDemoApplication.class)) {
 			FunctionCatalog catalog = context.getBean(FunctionCatalog.class);
-			CloudEventAttributesProvider ceAttrProvider = new DefaultCloudEventAttributesProvider();
 			Message<String> binaryCloudEventMessage = MessageBuilder
 					.withPayload("{\"releaseDate\":\"24-03-2004\", \"releaseName\":\"Spring Framework\", \"version\":\"1.0\"}")
-					.copyHeaders(ceAttrProvider.get("spring.io/spring-event", "com.example.springevent"))
+					.copyHeaders(CloudEventMessageUtils.get("spring.io/spring-event", "com.example.springevent"))
 					.build();
 
 			/*
@@ -88,10 +85,9 @@ public class CloudeventDemoApplicationFunctionTests {
 	public void demoPureFunctionProduceConsumeCloudEventAsPojo() {
 		try(ConfigurableApplicationContext context = SpringApplication.run(CloudeventDemoApplication.class)) {
 			FunctionCatalog catalog = context.getBean(FunctionCatalog.class);
-			CloudEventAttributesProvider ceAttrProvider = new DefaultCloudEventAttributesProvider();
 			Message<String> binaryCloudEventMessage = MessageBuilder
 					.withPayload("{\"releaseDate\":\"24-03-2004\", \"releaseName\":\"Spring Framework\", \"version\":\"1.0\"}")
-					.copyHeaders(ceAttrProvider.get("spring.io/spring-event", "com.example.springevent"))
+					.copyHeaders(CloudEventMessageUtils.get("spring.io/spring-event", "com.example.springevent"))
 					.build();
 
 			/*

spring-cloud-function-samples/function-sample-cloudevent/src/test/java/io/spring/cloudevent/CloudeventDemoApplicationRESTTests.java

@@ -35,6 +35,7 @@ import org.springframework.cloud.function.cloudevent.CloudEventJsonMessageConver
 import org.springframework.cloud.function.cloudevent.CloudEventMessageUtils;
 import org.springframework.cloud.function.cloudevent.DefaultCloudEventAttributesProvider;
 import org.springframework.cloud.function.json.JsonMapper;
+import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.http.HttpHeaders;
@@ -241,6 +242,51 @@ public class CloudeventDemoApplicationRESTTests {
 			.isEqualTo(Collections.singletonList(SpringReleaseEvent.class.getName()));
 	}
 
+	@Test
+    public void testAsStructuralPojoToPojo() throws Exception {
+        ApplicationContext context = SpringApplication.run(CloudeventDemoApplication.class);
+        JsonMapper mapper = context.getBean(JsonMapper.class);
+
+        String payload = "{\n" +
+                "    \"specversion\" : \"1.0\",\n" +
+                "    \"type\" : \"org.springframework\",\n" +
+                "    \"source\" : \"https://spring.io/\",\n" +
+                "    \"id\" : \"A234-1234-1234\",\n" +
+//                "    \"ce-datacontenttype\" : \"application/json\",\n" +
+                "    \"data\" : {\n" +
+                "        \"version\" : \"1.0\",\n" +
+                "        \"releaseName\" : \"Spring Framework\",\n" +
+                "        \"releaseDate\" : \"24-03-2004\"\n" +
+                "    }\n" +
+                "}";
+
+        System.out.println(payload);
+        HttpHeaders headers = new HttpHeaders();
+        headers.setContentType(MediaType.valueOf("application/cloudevents+json;charset=utf-8"));
+
+        RequestEntity<String> re = new RequestEntity<>(payload, headers, HttpMethod.POST, this.constructURI("/consumeAndProduceCloudEventAsPojoToPojo"));
+        ResponseEntity<String> response = testRestTemplate.exchange(re, String.class);
+
+        SpringReleaseEvent springReleaseEvent = mapper.fromJson(response.getBody(), SpringReleaseEvent.class);
+
+        assertThat(springReleaseEvent.getReleaseName()).isEqualTo("Spring Framework");
+        assertThat(springReleaseEvent.getVersion()).isEqualTo("2.0");
+
+        re = new RequestEntity<>(payload, headers, HttpMethod.POST, this.constructURI("/consumeAndProduceCloudEventAsMapToMap"));
+        response = testRestTemplate.exchange(re, String.class);
+
+        springReleaseEvent = mapper.fromJson(response.getBody(), SpringReleaseEvent.class);
+
+        assertThat(springReleaseEvent.getReleaseName()).isEqualTo("Spring Framework");
+        assertThat(springReleaseEvent.getVersion()).isEqualTo("10.0");
+
+
+//        assertThat(response.getHeaders().get(CloudEventMessageUtils.CE_SOURCE))
+//		.isEqualTo(Collections.singletonList("http://spring.io/application-application"));
+//        assertThat(response.getHeaders().get(CloudEventMessageUtils.CE_TYPE))
+//		.isEqualTo(Collections.singletonList(SpringReleaseEvent.class.getName()));
+    }
+
 	private URI constructURI(String path) throws Exception {
 		return new URI("http://localhost:" + System.getProperty("server.port") + path);
 	}