Fix Elasticsearch template condition if no client is defined

This commit makes sure to backoff if a Client bean is not available.

Closes gh-10143

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/data/elasticsearch/ElasticsearchDataAutoConfiguration.java

 /*
- * Copyright 2012-2015 the original author or authors.
+ * 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.
@@ -20,6 +20,7 @@ import org.elasticsearch.client.Client;
 
 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;
@@ -49,6 +50,7 @@ public class ElasticsearchDataAutoConfiguration {
 
 	@Bean
 	@ConditionalOnMissingBean
+	@ConditionalOnBean(Client.class)
 	public ElasticsearchTemplate elasticsearchTemplate(Client client,
 			ElasticsearchConverter converter) {
 		try {

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/elasticsearch/ElasticsearchDataAutoConfigurationTests.java

@@ -46,6 +46,14 @@ public class ElasticsearchDataAutoConfigurationTests {
 		}
 	}
 
+	@Test
+	public void templateBackOffWithNoClient() {
+		this.context = new AnnotationConfigApplicationContext(
+				ElasticsearchDataAutoConfiguration.class);
+		assertThat(this.context.getBeanNamesForType(ElasticsearchTemplate.class))
+				.isEmpty();
+	}
+
 	@Test
 	public void templateExists() {
 		load("spring.data.elasticsearch.properties.path.data:target/data",