INT-3939: Consistency for Redis Queue Gateways

JIRA: https://jira.spring.io/browse/INT-3939

Previously `RedisQueueInboundGateway` and `RedisQueueOutboundGateway` used different `RedisSerializer`s
for non-String objects.

* Change the default to the `JdkSerializationRedisSerializer` for the consistency in case of client/server scenarios.

The previous behavior with the `StringRedisSerializer` can be reinstated with `serializer` injection.

Doc Polishing.

spring-integration-redis/src/main/java/org/springframework/integration/redis/inbound/RedisQueueInboundGateway.java

@@ -25,6 +25,7 @@ import org.springframework.core.task.SimpleAsyncTaskExecutor;
 import org.springframework.data.redis.connection.RedisConnectionFactory;
 import org.springframework.data.redis.core.BoundListOperations;
 import org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.data.redis.serializer.JdkSerializationRedisSerializer;
 import org.springframework.data.redis.serializer.RedisSerializer;
 import org.springframework.data.redis.serializer.StringRedisSerializer;
 import org.springframework.integration.channel.MessagePublishingErrorHandler;
@@ -69,7 +70,7 @@ public class RedisQueueInboundGateway extends MessagingGatewaySupport implements
 
 	private volatile Executor taskExecutor;
 
-	private volatile RedisSerializer<?> serializer = new StringRedisSerializer();
+	private volatile RedisSerializer<?> serializer = new JdkSerializationRedisSerializer();
 
 	private volatile long receiveTimeout = DEFAULT_RECEIVE_TIMEOUT;
 
@@ -84,7 +85,7 @@ public class RedisQueueInboundGateway extends MessagingGatewaySupport implements
 	private volatile Runnable stopCallback;
 
 	/**
-	 * @param queueName         Must not be an empty String
+	 * @param queueName Must not be an empty String
 	 * @param connectionFactory Must not be null
 	 */
 	public RedisQueueInboundGateway(String queueName, RedisConnectionFactory connectionFactory) {

spring-integration-redis/src/main/java/org/springframework/integration/redis/outbound/RedisQueueOutboundGateway.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014 the original author or authors
+ * Copyright 2014-2016 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.
@@ -84,7 +84,7 @@ public class RedisQueueOutboundGateway extends AbstractReplyProducingMessageHand
 
 	@Override
 	public String getComponentType() {
-		return "redis:queue-outbound-gatewway";
+		return "redis:queue-outbound-gateway";
 	}
 
 	@Override
@@ -111,7 +111,7 @@ public class RedisQueueOutboundGateway extends AbstractReplyProducingMessageHand
 
 		BoundListOperations<String, Object> boundListOperations = template.boundListOps(uuid + QUEUE_NAME_SUFFIX);
 		byte[] reply = (byte[]) boundListOperations.rightPop(this.receiveTimeout, TimeUnit.MILLISECONDS);
-		if(reply != null && reply.length > 0) {
+		if (reply != null && reply.length > 0) {
 			Object replyMessage = this.serializer.deserialize(reply);
 			if (replyMessage == null) {
 				return null;

spring-integration-redis/src/test/java/org/springframework/integration/redis/config/RedisQueueGatewayIntegrationTests-context.xml

@@ -28,20 +28,15 @@
 									  queue="#{redisQueue.toString()}"
 									  reply-timeout="1000"
 									  requires-reply="true"
-									  reply-channel="outputChannel"
-									  serializer="serializer"/>
-
-
-	<bean id="serializer" class="org.springframework.data.redis.serializer.StringRedisSerializer"/>
+									  reply-channel="outputChannel"/>
 
 	<int-redis:queue-inbound-gateway id="inboundGateway"
 									 queue="#{redisQueue.toString()}"
 									 request-channel="requestChannel"
-									 serializer="serializer"
 									 reply-timeout="20001"
 									 receive-timeout="100"
 									 request-timeout="20000"/>
 
-	<int:service-activator input-channel="requestChannel" expression="payload.toUpperCase()"/>
+	<int:service-activator input-channel="requestChannel" expression="payload + 1"/>
 
 </beans>

spring-integration-redis/src/test/java/org/springframework/integration/redis/config/RedisQueueGatewayIntegrationTests.java

@@ -78,10 +78,10 @@ public class RedisQueueGatewayIntegrationTests extends RedisAvailableTests {
 	@Test
 	@RedisAvailable
 	public void testRequestWithReply() throws Exception {
-		this.sendChannel.send(new GenericMessage<String>("test1"));
+		this.sendChannel.send(new GenericMessage<Integer>(1));
 		Message<?> receive = this.outputChannel.receive(10000);
 		assertNotNull(receive);
-		assertEquals("test1".toUpperCase(), receive.getPayload());
+		assertEquals(2, receive.getPayload());
 	}
 
 	@Test
@@ -124,10 +124,10 @@ public class RedisQueueGatewayIntegrationTests extends RedisAvailableTests {
 		this.inboundGateway.setExtractPayload(false);
 		this.outboundGateway.setSerializer(new JdkSerializationRedisSerializer());
 		this.outboundGateway.setExtractPayload(false);
-		this.sendChannel.send(new GenericMessage<String>("test1"));
+		this.sendChannel.send(new GenericMessage<Integer>(2));
 		Message<?> receive = this.outputChannel.receive(10000);
 		assertNotNull(receive);
-		assertEquals("test1".toUpperCase(), receive.getPayload());
+		assertEquals(3, receive.getPayload());
 		this.inboundGateway.setSerializer(new StringRedisSerializer());
 		this.inboundGateway.setExtractPayload(true);
 		this.outboundGateway.setSerializer(new StringRedisSerializer());

src/reference/asciidoc/redis.adoc

@@ -732,7 +732,8 @@ Mutually exclusive with 'redis-template' attribute.
 <8> The `RedisSerializer` bean reference.
 Can be an empty string, which means 'no serializer'.
 In this case the raw `byte[]` from the inbound Redis message is sent to the `channel` as the `Message` payload.
-By default it is a `StringRedisSerializer`.
+By default it is a `JdkSerializationRedisSerializer`. (Note that in releases before _version 4.3_, it was a
+`StringRedisSerializer` by default; to restore that behavior provide a reference to a `StringRedisSerializer`).
 
 
 <9> The timeout in milliseconds to wait until the receive message will be get or not.

src/reference/asciidoc/whats-new.adoc

@@ -80,12 +80,20 @@ See <<content-type-conversion-outbound>> for more information.
 
 ==== Redis Changes
 
+===== List Push/Pop Direction
+
 Previously, the queue channel adapters always used the Redis List in a fixed direction,
 pushing to the left end and reading from the right end.
 It is now possible to configure the reading and writing direction using `rightPop` and `leftPush` options for the
 `RedisQueueMessageDrivenEndpoint` and `RedisQueueOutboundChannelAdapter` respectively.
 See <<redis-queue-inbound-channel-adapter>> and <<redis-queue-outbound-channel-adapter>> for more information.
 
+===== Queue Inbound Gateway Default Serializer
+
+The default serializer in the inbound gateway has been changed to a `JdkSerializationRedisSerializer` for compatibility
+with the outbound gateway.
+See <<redis-queue-inbound-gateway>> for more information.
+
 ==== HTTP Changes
 
 Previously, with requests that had a body (such as `POST`) that had no `content-type` header, the body was ignored.