Add auto-configuration for reactive Redis

This commit provides an auto-configuration for reactive Redis and a
starter that provides Lettuce as Jedis doesn't support reactive
operations.

There are no support for reactive redis repositories at the moment so
only a `ReactiveRedisTemplate` is auto-configured if necessary.

Closes gh-8053

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/data/redis/RedisReactiveAutoConfiguration.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright 2012-2017 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.boot.autoconfigure.data.redis;
+
+import reactor.core.publisher.Flux;
+
+import org.springframework.boot.autoconfigure.AutoConfigureAfter;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.io.ResourceLoader;
+import org.springframework.data.redis.connection.ReactiveRedisConnectionFactory;
+import org.springframework.data.redis.core.ReactiveRedisTemplate;
+import org.springframework.data.redis.serializer.JdkSerializationRedisSerializer;
+import org.springframework.data.redis.serializer.RedisSerializationContext;
+
+/**
+ * {@link EnableAutoConfiguration Auto-configuration} for Spring Data's reactive Redis
+ * support.
+ *
+ * @author Mark Paluch
+ * @author Stephane Nicoll
+ * @since 2.0.0
+ */
+@Configuration
+@ConditionalOnClass({ ReactiveRedisConnectionFactory.class, ReactiveRedisTemplate.class,
+		Flux.class })
+@AutoConfigureAfter(RedisAutoConfiguration.class)
+public class RedisReactiveAutoConfiguration {
+
+	@Bean
+	@ConditionalOnMissingBean(name = "reactiveRedisTemplate")
+	@ConditionalOnBean(ReactiveRedisConnectionFactory.class)
+	public ReactiveRedisTemplate<Object, Object> reactiveRedisTemplate(
+			ReactiveRedisConnectionFactory reactiveRedisConnectionFactory,
+			ResourceLoader resourceLoader) {
+
+		JdkSerializationRedisSerializer jdkSerializer =
+				new JdkSerializationRedisSerializer(resourceLoader.getClassLoader());
+
+		RedisSerializationContext<Object, Object> serializationContext =
+				RedisSerializationContext.newSerializationContext()
+						.key(jdkSerializer)
+						.value(jdkSerializer)
+						.hashKey(jdkSerializer)
+						.hashValue(jdkSerializer).build();
+		return new ReactiveRedisTemplate<>(reactiveRedisConnectionFactory,
+				serializationContext);
+	}
+
+}

spring-boot-autoconfigure/src/main/resources/META-INF/spring.factories

@@ -49,6 +49,7 @@ org.springframework.boot.autoconfigure.data.neo4j.Neo4jDataAutoConfiguration,\
 org.springframework.boot.autoconfigure.data.neo4j.Neo4jRepositoriesAutoConfiguration,\
 org.springframework.boot.autoconfigure.data.solr.SolrRepositoriesAutoConfiguration,\
 org.springframework.boot.autoconfigure.data.redis.RedisAutoConfiguration,\
+org.springframework.boot.autoconfigure.data.redis.RedisReactiveAutoConfiguration,\
 org.springframework.boot.autoconfigure.data.redis.RedisRepositoriesAutoConfiguration,\
 org.springframework.boot.autoconfigure.data.rest.RepositoryRestMvcAutoConfiguration,\
 org.springframework.boot.autoconfigure.data.web.SpringDataWebAutoConfiguration,\

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/redis/RedisReactiveAutoConfigurationTests.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright 2012-2017 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.boot.autoconfigure.data.redis;
+
+import java.util.Map;
+
+import org.junit.After;
+import org.junit.Test;
+
+import org.springframework.boot.test.util.EnvironmentTestUtils;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.data.redis.core.ReactiveRedisTemplate;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link RedisReactiveAutoConfiguration}.
+ *
+ * @author Stephane Nicoll
+ */
+public class RedisReactiveAutoConfigurationTests {
+
+	private AnnotationConfigApplicationContext context;
+
+	@After
+	public void close() {
+		if (this.context != null) {
+			this.context.close();
+		}
+	}
+
+	@Test
+	public void testDefaultRedisConfiguration() {
+		load();
+		Map<String, ReactiveRedisTemplate> beans = this.context.getBeansOfType(
+				ReactiveRedisTemplate.class);
+		assertThat(beans).containsOnlyKeys("reactiveRedisTemplate");
+	}
+
+
+	private void load(String... environment) {
+		AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext();
+		EnvironmentTestUtils.addEnvironment(ctx, environment);
+		ctx.register(RedisAutoConfiguration.class, RedisReactiveAutoConfiguration.class);
+		ctx.refresh();
+		this.context = ctx;
+	}
+
+}