Merge pull request #20109 from nosan

* pr/20109:
  Polish "Create HazelCastClient if necessary"
  Create HazelCastClient if necessary

Closes gh-20109

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/hazelcast/HazelcastClientFactory.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -72,7 +72,7 @@ public class HazelcastClientFactory {
 	 */
 	public HazelcastInstance getHazelcastInstance() {
 		if (StringUtils.hasText(this.clientConfig.getInstanceName())) {
-			return HazelcastClient.getHazelcastClientByName(this.clientConfig.getInstanceName());
+			return HazelcastClient.getOrCreateHazelcastClient(this.clientConfig);
 		}
 		return HazelcastClient.newHazelcastClient(this.clientConfig);
 	}

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/hazelcast/HazelcastAutoConfigurationClientTests.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -16,6 +16,7 @@
 
 package org.springframework.boot.autoconfigure.hazelcast;
 
+import com.hazelcast.client.HazelcastClient;
 import com.hazelcast.client.config.ClientConfig;
 import com.hazelcast.client.impl.clientside.HazelcastClientProxy;
 import com.hazelcast.config.Config;
@@ -124,6 +125,16 @@ class HazelcastAutoConfigurationClientTests {
 						.getBean(HazelcastInstance.class).isInstanceOf(HazelcastClientProxy.class));
 	}
 
+	@Test
+	void clientConfigWithInstanceNameCreatesClientIfNecessary() {
+		assertThat(HazelcastClient.getHazelcastClientByName("spring-boot")).isNull();
+		this.contextRunner
+				.withPropertyValues("spring.hazelcast.config=classpath:org/springframework/"
+						+ "boot/autoconfigure/hazelcast/hazelcast-client-instance.xml")
+				.run((context) -> assertThat(context).getBean(HazelcastInstance.class)
+						.extracting(HazelcastInstance::getName).isEqualTo("spring-boot"));
+	}
+
 	private ContextConsumer<AssertableApplicationContext> assertSpecificHazelcastClient(String label) {
 		return (context) -> assertThat(context).getBean(HazelcastInstance.class).isInstanceOf(HazelcastInstance.class)
 				.has(labelEqualTo(label));

spring-boot-project/spring-boot-autoconfigure/src/test/resources/org/springframework/boot/autoconfigure/hazelcast/hazelcast-client-instance.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<hazelcast-client xmlns="http://www.hazelcast.com/schema/client-config"
+				  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+				  xsi:schemaLocation="http://www.hazelcast.com/schema/client-config hazelcast-client-config-3.12.xsd">
+
+	<instance-name>spring-boot</instance-name>
+
+</hazelcast-client>