INT-8 refactored single claim check transformer into separate in/out implementations

org.springframework.integration/src/main/java/org/springframework/integration/transformer/ClaimCheckInTransformer.java

@@ -16,23 +16,27 @@
 
 package org.springframework.integration.transformer;
 
-import java.util.UUID;
-
 import org.springframework.integration.core.Message;
 import org.springframework.integration.message.MessageBuilder;
 import org.springframework.integration.store.MessageStore;
 import org.springframework.util.Assert;
 
 /**
+ * Transformer that stores a Message and returns a new Message whose payload
+ * is the id of the stored Message.
+ * 
  * @author Mark Fisher
  * @since 2.0
  */
-public class ClaimCheckTransformer extends AbstractTransformer {
+public class ClaimCheckInTransformer extends AbstractTransformer {
 
 	private final MessageStore messageStore;
 
 
-	public ClaimCheckTransformer(MessageStore messageStore) {
+	/**
+	 * Create a claim check-in transformer that will delegate to the provided MessageStore.
+	 */
+	public ClaimCheckInTransformer(MessageStore messageStore) {
 		Assert.notNull(messageStore, "MessageStore must not be null");
 		this.messageStore = messageStore;
 	}
@@ -43,29 +47,11 @@ public class ClaimCheckTransformer extends AbstractTransformer {
 		Assert.notNull(message, "message must not be null");
 		Object payload = message.getPayload();
 		Assert.notNull(payload, "payload must not be null");
-		MessageBuilder<?> responseBuilder = null;
-		if (payload instanceof UUID) {
-			Message<?> original = this.retrieveMessage((UUID) payload);
-			responseBuilder = MessageBuilder.fromMessage(original);
-		}
-		else {
-			this.storeMessage(message);
-			responseBuilder = MessageBuilder.withPayload(message.getHeaders().getId());
-		}
+		Message<?> storedMessage = this.messageStore.addMessage(message);
+		MessageBuilder<?> responseBuilder = MessageBuilder.withPayload(storedMessage.getHeaders().getId());
 		// headers on the 'current' message take precedence
 		responseBuilder.copyHeaders(message.getHeaders());
 		return responseBuilder.build();
 	}
 
-
-	private Message<?> retrieveMessage(UUID id) {
-		Message<?> result = this.messageStore.getMessage(id);
-		Assert.notNull(result, "unable to locate Message for claim check ID: " + id);
-		return result;
-	}
-
-	private void storeMessage(Message<?> message) {
-		this.messageStore.addMessage(message);
-	}
-
 }

org.springframework.integration/src/main/java/org/springframework/integration/transformer/ClaimCheckOutTransformer.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2002-2010 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.integration.transformer;
+
+import java.util.UUID;
+
+import org.springframework.integration.core.Message;
+import org.springframework.integration.message.MessageBuilder;
+import org.springframework.integration.store.MessageStore;
+import org.springframework.util.Assert;
+
+/**
+ * Transformer that accepts a Message whose payload is a UUID and retrieves the
+ * Message associated with that id from a MessageStore if available (else null).
+ * 
+ * @author Mark Fisher
+ * @since 2.0
+ */
+public class ClaimCheckOutTransformer extends AbstractTransformer {
+
+	private final MessageStore messageStore;
+
+
+	/**
+	 * Create a claim check-out transformer that will delegate to the provided MessageStore.
+	 */
+	public ClaimCheckOutTransformer(MessageStore messageStore) {
+		Assert.notNull(messageStore, "MessageStore must not be null");
+		this.messageStore = messageStore;
+	}
+
+
+	@Override
+	protected Object doTransform(Message<?> message) throws Exception {
+		Assert.notNull(message, "message must not be null");
+		Assert.isTrue(message.getPayload() instanceof UUID, "payload must be a UUID");
+		UUID id = (UUID) message.getPayload();
+		Message<?> retrievedMessage = this.messageStore.getMessage(id);
+		Assert.notNull(retrievedMessage, "unable to locate Message for ID: " + id);
+		MessageBuilder<?> responseBuilder = MessageBuilder.fromMessage(retrievedMessage);
+		// headers on the 'current' message take precedence
+		responseBuilder.copyHeaders(message.getHeaders());
+		return responseBuilder.build();
+	}
+
+}

org.springframework.integration/src/test/java/org/springframework/integration/transformer/ClaimCheckTransformerTests.java

@@ -36,7 +36,7 @@ public class ClaimCheckTransformerTests {
 	@Test
 	public void store() {
 		MessageStore store = new SimpleMessageStore(10);
-		ClaimCheckTransformer transformer = new ClaimCheckTransformer(store);
+		ClaimCheckInTransformer transformer = new ClaimCheckInTransformer(store);
 		Message<?> input = MessageBuilder.withPayload("test").build();
 		Message<?> output = transformer.transform(input);
 		assertEquals(input.getHeaders().getId(), output.getPayload());
@@ -48,7 +48,7 @@ public class ClaimCheckTransformerTests {
 		Message<?> message = MessageBuilder.withPayload("test").build();
 		UUID storedId = message.getHeaders().getId();
 		store.addMessage(message);
-		ClaimCheckTransformer transformer = new ClaimCheckTransformer(store);
+		ClaimCheckOutTransformer transformer = new ClaimCheckOutTransformer(store);
 		Message<?> input = MessageBuilder.withPayload(storedId).build();
 		Message<?> output = transformer.transform(input);
 		assertEquals("test", output.getPayload());
@@ -57,7 +57,7 @@ public class ClaimCheckTransformerTests {
 	@Test(expected = MessageTransformationException.class)
 	public void unknown() {
 		MessageStore store = new SimpleMessageStore(10);
-		ClaimCheckTransformer transformer = new ClaimCheckTransformer(store);
+		ClaimCheckOutTransformer transformer = new ClaimCheckOutTransformer(store);
 		transformer.transform(MessageBuilder.withPayload(UUID.randomUUID()).build());
 	}