Polish "Make NarayanaRecoveryManagerBean conditional on missing bean"

Closes gh-9724

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/transaction/jta/NarayanaJtaConfiguration.java

 /*
- * Copyright 2012-2016 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.

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/transaction/jta/JtaAutoConfigurationTests.java

 /*
- * Copyright 2012-2016 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.
@@ -44,6 +44,7 @@ import org.junit.rules.ExpectedException;
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.NoSuchBeanDefinitionException;
 import org.springframework.boot.autoconfigure.transaction.TransactionAutoConfiguration;
+import org.springframework.boot.autoconfigure.transaction.jta.JtaAutoConfigurationTests.CustomNarayanaRecoveryManagerConfiguration.CustomNarayanaRecoveryManagerBean;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.boot.jta.XAConnectionFactoryWrapper;
 import org.springframework.boot.jta.XADataSourceWrapper;
@@ -55,6 +56,7 @@ import org.springframework.boot.jta.bitronix.PoolingConnectionFactoryBean;
 import org.springframework.boot.jta.bitronix.PoolingDataSourceBean;
 import org.springframework.boot.jta.narayana.NarayanaBeanFactoryPostProcessor;
 import org.springframework.boot.jta.narayana.NarayanaConfigurationBean;
+import org.springframework.boot.jta.narayana.NarayanaRecoveryManagerBean;
 import org.springframework.boot.test.util.EnvironmentTestUtils;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.context.annotation.Bean;
@@ -294,6 +296,16 @@ public class JtaAutoConfigurationTests {
 		assertThat(transactionManager.isRollbackOnCommitFailure()).isTrue();
 	}
 
+	@Test
+	public void narayanaRecoveryManagerBeanCanBeCustomized() {
+		this.context = new AnnotationConfigApplicationContext();
+		this.context.register(CustomNarayanaRecoveryManagerConfiguration.class,
+				JtaProperties.class, NarayanaJtaConfiguration.class);
+		this.context.refresh();
+		assertThat(this.context.getBean(NarayanaRecoveryManagerBean.class))
+				.isInstanceOf(CustomNarayanaRecoveryManagerBean.class);
+	}
+
 	@Configuration
 	@EnableConfigurationProperties(JtaProperties.class)
 	public static class JtaPropertiesConfiguration {
@@ -336,4 +348,25 @@ public class JtaAutoConfigurationTests {
 
 	}
 
+	@Configuration
+	public static class CustomNarayanaRecoveryManagerConfiguration {
+
+		@Bean
+		public NarayanaRecoveryManagerBean customRecoveryManagerBean(
+				RecoveryManagerService recoveryManagerService) {
+			return new CustomNarayanaRecoveryManagerBean(recoveryManagerService);
+		}
+
+		static final class CustomNarayanaRecoveryManagerBean
+				extends NarayanaRecoveryManagerBean {
+
+			private CustomNarayanaRecoveryManagerBean(
+					RecoveryManagerService recoveryManagerService) {
+				super(recoveryManagerService);
+			}
+
+		}
+
+	}
+
 }