Initial Commit

Migrating the existing structure from the following location:
https://github.com/spring-cloud-stream-app-starters/stream-applications/tree/restructuring

functions/function/payload-converter-function/src/main/java/functions/ByteArrayTextToString.java

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+/*
+ * Copyright 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.
+ * 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 functions;
+
+import java.util.function.Function;
+
+import org.springframework.messaging.Message;
+import org.springframework.messaging.MessageHeaders;
+import org.springframework.messaging.support.MessageBuilder;
+import org.springframework.util.MimeTypeUtils;
+
+/**
+ *
+ * @author Christian Tzolov
+ */
+public class ByteArrayTextToString implements Function<Message<?>, Message<?>> {
+
+	@Override
+	public Message<?> apply(Message<?> message) {
+
+		if (message.getPayload() instanceof byte[]) {
+			final MessageHeaders headers = message.getHeaders();
+			String contentType = headers.containsKey(MessageHeaders.CONTENT_TYPE)
+					? headers.get(MessageHeaders.CONTENT_TYPE).toString()
+					: MimeTypeUtils.APPLICATION_JSON_VALUE;
+
+			if (contentType.contains("text") || contentType.contains("json") || contentType.contains("x-spring-tuple")) {
+				message = MessageBuilder.withPayload(new String(((byte[]) message.getPayload())))
+						.copyHeaders(message.getHeaders())
+						.build();
+			}
+		}
+
+		return message;
+	}
+}
+

functions/function/payload-converter-function/src/test/java/functions/ByteArrayTextToStringTests.java

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+/*
+ * Copyright (c) 2011-2020 Pivotal Software Inc, All Rights Reserved.
+ *
+ * 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 functions;
+
+import java.util.Collections;
+import java.util.function.Function;
+
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.messaging.Message;
+import org.springframework.messaging.MessageHeaders;
+import org.springframework.messaging.support.GenericMessage;
+import org.springframework.util.MimeTypeUtils;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class ByteArrayTextToStringTests {
+
+	private static final String MESSAGE = "hello world";
+	private static Function<Message<?>, Message<?>> converter;
+
+	@BeforeAll
+	static void before() {
+		converter = new ByteArrayTextToString();
+	}
+
+	@Test
+	public void testDefaultNoContentType() {
+		Message<?> converted = converter.apply(new GenericMessage<>(MESSAGE.getBytes()));
+		assertThat(converted).isNotNull().extracting(Message::getPayload).isEqualTo(MESSAGE);
+
+		converted = converter.apply(new GenericMessage<>(MESSAGE)); // String
+		assertThat(converted).isNotNull().extracting(Message::getPayload).isEqualTo(MESSAGE);
+	}
+
+	@Test
+	public void testApplicationJsonContentType() {
+		Message<?> converted = converter.apply(new GenericMessage<>(MESSAGE.getBytes(),
+				Collections.singletonMap(MessageHeaders.CONTENT_TYPE, MimeTypeUtils.APPLICATION_JSON_VALUE)));
+		assertThat(converted).isNotNull().extracting(Message::getPayload).isEqualTo("hello world");
+	}
+
+	@Test
+	public void testPlainTextContentType() {
+		Message<?> converted = converter.apply(new GenericMessage<>(MESSAGE.getBytes(),
+				Collections.singletonMap(MessageHeaders.CONTENT_TYPE, MimeTypeUtils.TEXT_PLAIN_VALUE)));
+		assertThat(converted).isNotNull().extracting(Message::getPayload).isEqualTo(MESSAGE);
+	}
+
+	@Test
+	public void testOctetContentType() {
+		Message<?> converted = converter.apply(new GenericMessage<>(MESSAGE.getBytes(),
+				Collections.singletonMap(MessageHeaders.CONTENT_TYPE, MimeTypeUtils.APPLICATION_OCTET_STREAM_VALUE)));
+		assertThat(converted).isNotNull().extracting(Message::getPayload).isEqualTo(MESSAGE.getBytes());
+	}
+
+	@Test
+	public void testRandomNonTextContentType() {
+		Message<?> converted = converter.apply(new GenericMessage<>(MESSAGE.getBytes(),
+				Collections.singletonMap(MessageHeaders.CONTENT_TYPE, "Random Content Type")));
+		assertThat(converted).isNotNull().extracting(Message::getPayload).isEqualTo(MESSAGE.getBytes());
+	}
+
+}