Fix JMS health indicator

This commit improves the JMS health indicator to identify a broken broker
that uses failover. An attempt to start the connection is a good way to
make sure that it is effectively available.

Closes gh-6818

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/health/JmsHealthIndicator.java

 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2016 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.
@@ -37,6 +37,7 @@ public class JmsHealthIndicator extends AbstractHealthIndicator {
 	protected void doHealthCheck(Health.Builder builder) throws Exception {
 		Connection connection = this.connectionFactory.createConnection();
 		try {
+			connection.start();
 			builder.up().withDetail("provider",
 					connection.getMetaData().getJMSProviderName());
 		}

spring-boot-actuator/src/test/java/org/springframework/boot/actuate/health/JmsHealthIndicatorTests.java

 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2016 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.
@@ -22,6 +22,7 @@ import javax.jms.ConnectionMetaData;
 import javax.jms.JMSException;
 
 import org.junit.Test;
+import org.mockito.Mockito;
 
 import static org.junit.Assert.assertEquals;
 import static org.mockito.BDDMockito.given;
@@ -78,4 +79,21 @@ public class JmsHealthIndicatorTests {
 		verify(connection, times(1)).close();
 	}
 
+	@Test
+	public void jmsBrokerUsesFailover() throws JMSException {
+		ConnectionFactory connectionFactory = mock(ConnectionFactory.class);
+		ConnectionMetaData connectionMetaData = mock(ConnectionMetaData.class);
+		given(connectionMetaData.getJMSProviderName()).willReturn("JMS test provider");
+		Connection connection = mock(Connection.class);
+		given(connection.getMetaData()).willReturn(connectionMetaData);
+		Mockito.doThrow(new JMSException("Could not start", "123"))
+				.when(connection).start();
+		given(connectionFactory.createConnection())
+				.willReturn(connection);
+		JmsHealthIndicator indicator = new JmsHealthIndicator(connectionFactory);
+		Health health = indicator.health();
+		assertEquals(Status.DOWN, health.getStatus());
+		assertEquals(null, health.getDetails().get("provider"));
+	}
+
 }