Prevent attempt to export MBean for DataSource retreived from JNDI

Tomcat 8's default DataSource implemention is an MBean. Previously,
when such a DataSource was consumed from JNDI and an MBeanExporter had
been auto-configured an attempt would be made to export this MBean to
the MBean server. This would fail due to Tomcat having already
registered the MBean.

This commit updates JndiDataSourceAutoConfiguration to instruct the
MBeanExporter (if there is one) not to export a DataSource MBean
that's been retrieved from JNDI. The assumption is that any MBean in
JNDI will have already been registered with the MBean server by the
same infrastructure that registered it with JNDI.

Fixes gh-2397

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jdbc/JndiDataSourceAutoConfiguration.java

 /*
- * Copyright 2012-2014 the original author or authors.
+ * Copyright 2012-2015 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.
@@ -18,6 +18,7 @@ package org.springframework.boot.autoconfigure.jdbc;
 
 import javax.sql.DataSource;
 
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.AutoConfigureBefore;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
@@ -28,12 +29,15 @@ import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseType;
 import org.springframework.jdbc.datasource.lookup.JndiDataSourceLookup;
+import org.springframework.jmx.export.MBeanExporter;
+import org.springframework.jmx.support.JmxUtils;
 
 /**
  * {@link EnableAutoConfiguration Auto-configuration} for a JNDI located
  * {@link DataSource}.
  *
  * @author Phillip Webb
+ * @author Andy Wilkinson
  * @since 1.2.0
  */
 @Configuration
@@ -44,11 +48,22 @@ import org.springframework.jdbc.datasource.lookup.JndiDataSourceLookup;
 @EnableConfigurationProperties(DataSourceProperties.class)
 public class JndiDataSourceAutoConfiguration {
 
+	@Autowired(required = false)
+	private MBeanExporter mbeanExporter;
+
 	@Bean(destroyMethod = "")
 	@ConditionalOnMissingBean
 	public DataSource dataSource(DataSourceProperties properties) {
 		JndiDataSourceLookup dataSourceLookup = new JndiDataSourceLookup();
-		return dataSourceLookup.getDataSource(properties.getJndiName());
+		DataSource dataSource = dataSourceLookup.getDataSource(properties.getJndiName());
+		excludeMBeanIfNecessary(dataSource, "dataSource");
+		return dataSource;
+	}
+
+	private void excludeMBeanIfNecessary(Object candidate, String beanName) {
+		if (this.mbeanExporter != null && JmxUtils.isMBean(candidate.getClass())) {
+			this.mbeanExporter.addExcludedBean(beanName);
+		}
 	}
 
 }

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/jdbc/JndiDataSourceAutoConfigurationTests.java

+/*
+ * Copyright 2012-2015 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.jdbc;
+
+import java.util.Set;
+
+import javax.naming.NamingException;
+import javax.sql.DataSource;
+
+import org.apache.commons.dbcp2.BasicDataSource;
+import org.junit.After;
+import org.junit.Test;
+import org.springframework.beans.DirectFieldAccessor;
+import org.springframework.boot.test.EnvironmentTestUtils;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.jmx.export.MBeanExporter;
+import org.springframework.mock.jndi.SimpleNamingContextBuilder;
+
+import static org.hamcrest.Matchers.contains;
+import static org.hamcrest.Matchers.hasSize;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Tests for {@link JndiDataSourceAutoConfiguration}
+ *
+ * @author Andy Wilkinson
+ */
+public class JndiDataSourceAutoConfigurationTests {
+
+	private AnnotationConfigApplicationContext context;
+
+	private SimpleNamingContextBuilder jndi;
+
+	@After
+	public void cleanup() {
+		if (this.jndi != null) {
+			this.jndi.clear();
+		}
+		if (this.context != null) {
+			this.context.close();
+		}
+	}
+
+	@Test
+	public void dataSourceIsAvailableFromJndi() throws IllegalStateException,
+			NamingException {
+		DataSource dataSource = new BasicDataSource();
+		this.jndi = configureJndi("foo", dataSource);
+
+		this.context = new AnnotationConfigApplicationContext();
+		EnvironmentTestUtils.addEnvironment(this.context,
+				"spring.datasource.jndi-name:foo");
+		this.context.register(JndiDataSourceAutoConfiguration.class);
+		this.context.refresh();
+
+		assertEquals(dataSource, this.context.getBean(DataSource.class));
+	}
+
+	@SuppressWarnings("unchecked")
+	@Test
+	public void mbeanDataSourceIsExcludedFromExport() throws IllegalStateException,
+			NamingException {
+		DataSource dataSource = new BasicDataSource();
+		this.jndi = configureJndi("foo", dataSource);
+
+		this.context = new AnnotationConfigApplicationContext();
+		EnvironmentTestUtils.addEnvironment(this.context,
+				"spring.datasource.jndi-name:foo");
+		this.context.register(JndiDataSourceAutoConfiguration.class,
+				MBeanExporterConfiguration.class);
+		this.context.refresh();
+
+		assertEquals(dataSource, this.context.getBean(DataSource.class));
+		MBeanExporter exporter = this.context.getBean(MBeanExporter.class);
+		Set<String> excludedBeans = (Set<String>) new DirectFieldAccessor(exporter)
+				.getPropertyValue("excludedBeans");
+		assertThat(excludedBeans, contains("dataSource"));
+	}
+
+	@SuppressWarnings("unchecked")
+	@Test
+	public void standardDataSourceIsNotExcludedFromExport() throws IllegalStateException,
+			NamingException {
+		DataSource dataSource = new org.apache.commons.dbcp.BasicDataSource();
+		this.jndi = configureJndi("foo", dataSource);
+
+		this.context = new AnnotationConfigApplicationContext();
+		EnvironmentTestUtils.addEnvironment(this.context,
+				"spring.datasource.jndi-name:foo");
+		this.context.register(JndiDataSourceAutoConfiguration.class,
+				MBeanExporterConfiguration.class);
+		this.context.refresh();
+
+		assertEquals(dataSource, this.context.getBean(DataSource.class));
+		MBeanExporter exporter = this.context.getBean(MBeanExporter.class);
+		Set<String> excludedBeans = (Set<String>) new DirectFieldAccessor(exporter)
+				.getPropertyValue("excludedBeans");
+		assertThat(excludedBeans, hasSize(0));
+	}
+
+	private SimpleNamingContextBuilder configureJndi(String name, DataSource dataSource)
+			throws IllegalStateException, NamingException {
+		SimpleNamingContextBuilder builder = SimpleNamingContextBuilder
+				.emptyActivatedContextBuilder();
+		builder.bind(name, dataSource);
+		return builder;
+	}
+
+	private static class MBeanExporterConfiguration {
+
+		@Bean
+		MBeanExporter mbeanExporter() {
+			return new MBeanExporter();
+		}
+	}
+
+}