Add support for auto-configuration of Commons DBCP2

Closes gh-1292
Closes gh-1477

spring-boot-autoconfigure/pom.xml

@@ -75,6 +75,11 @@
 			<artifactId>activemq-pool</artifactId>
 			<optional>true</optional>
 		</dependency>
+		<dependency>
+			<groupId>org.apache.commons</groupId>
+			<artifactId>commons-dbcp2</artifactId>
+			<optional>true</optional>
+		</dependency>
 		<dependency>
 			<groupId>org.apache.solr</groupId>
 			<artifactId>solr-solrj</artifactId>

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

@@ -43,7 +43,8 @@ public class DataSourceBuilder {
 	private static final String[] DATA_SOURCE_TYPE_NAMES = new String[] {
 			"org.apache.tomcat.jdbc.pool.DataSource",
 			"com.zaxxer.hikari.HikariDataSource",
-			"org.apache.commons.dbcp.BasicDataSource" };
+			"org.apache.commons.dbcp.BasicDataSource",
+			"org.apache.commons.dbcp2.BasicDataSource" };
 
 	private Class<? extends DataSource> type;
 

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

@@ -45,9 +45,11 @@ import org.springframework.jdbc.core.namedparam.NamedParameterJdbcOperations;
 
 import com.zaxxer.hikari.HikariDataSource;
 
+import static org.hamcrest.Matchers.instanceOf;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 
 /**
@@ -70,8 +72,8 @@ public class DataSourceAutoConfigurationTests {
 	@After
 	public void restore() {
 		EmbeddedDatabaseConnection.override = null;
-		if (context != null) {
-			context.close();
+		if (this.context != null) {
+			this.context.close();
 		}
 	}
 
@@ -119,28 +121,26 @@ public class DataSourceAutoConfigurationTests {
 
 	@Test
 	public void testHikariIsFallback() throws Exception {
-		EnvironmentTestUtils.addEnvironment(this.context,
-				"spring.datasource.driverClassName:org.hsqldb.jdbcDriver",
-				"spring.datasource.url:jdbc:hsqldb:mem:testdb");
-		this.context.setClassLoader(new URLClassLoader(new URL[0], getClass()
-				.getClassLoader()) {
-			@Override
-			protected Class<?> loadClass(String name, boolean resolve)
-					throws ClassNotFoundException {
-				if (name.startsWith("org.apache.tomcat")) {
-					throw new ClassNotFoundException();
-				}
-				return super.loadClass(name, resolve);
-			}
-		});
-		this.context.register(DataSourceAutoConfiguration.class,
-				PropertyPlaceholderAutoConfiguration.class);
-		this.context.refresh();
-		DataSource bean = this.context.getBean(DataSource.class);
-		HikariDataSource pool = (HikariDataSource) bean;
+		HikariDataSource pool = testDataSourceFallback(HikariDataSource.class,
+				"org.apache.tomcat");
 		assertEquals("jdbc:hsqldb:mem:testdb", pool.getJdbcUrl());
 	}
 
+	@Test
+	public void commonsDbcpIsFallback() throws Exception {
+		BasicDataSource dataSource = testDataSourceFallback(BasicDataSource.class,
+				"org.apache.tomcat", "com.zaxxer.hikari");
+		assertEquals("jdbc:hsqldb:mem:testdb", dataSource.getUrl());
+	}
+
+	@Test
+	public void commonsDbcp2IsFallback() throws Exception {
+		org.apache.commons.dbcp2.BasicDataSource dataSource = testDataSourceFallback(
+				org.apache.commons.dbcp2.BasicDataSource.class, "org.apache.tomcat",
+				"com.zaxxer.hikari", "org.apache.commons.dbcp.");
+		assertEquals("jdbc:hsqldb:mem:testdb", dataSource.getUrl());
+	}
+
 	@Test
 	public void testEmbeddedTypeDefaultsUsername() throws Exception {
 		EnvironmentTestUtils.addEnvironment(this.context,
@@ -215,6 +215,34 @@ public class DataSourceAutoConfigurationTests {
 		assertNotNull(this.context.getBean(NamedParameterJdbcOperations.class));
 	}
 
+	@SuppressWarnings("unchecked")
+	private <T extends DataSource> T testDataSourceFallback(Class<T> expectedType,
+			final String... hiddenPackages) {
+		EnvironmentTestUtils.addEnvironment(this.context,
+				"spring.datasource.driverClassName:org.hsqldb.jdbcDriver",
+				"spring.datasource.url:jdbc:hsqldb:mem:testdb");
+		this.context.setClassLoader(new URLClassLoader(new URL[0], getClass()
+				.getClassLoader()) {
+			@Override
+			protected Class<?> loadClass(String name, boolean resolve)
+					throws ClassNotFoundException {
+				for (String hiddenPackage : hiddenPackages) {
+					if (name.startsWith(hiddenPackage)) {
+						throw new ClassNotFoundException();
+					}
+				}
+				return super.loadClass(name, resolve);
+			}
+		});
+		this.context.register(DataSourceAutoConfiguration.class,
+				PropertyPlaceholderAutoConfiguration.class);
+		this.context.refresh();
+		DataSource bean = this.context.getBean(DataSource.class);
+
+		assertThat(bean, instanceOf(expectedType));
+		return (T) bean;
+	}
+
 	@Configuration
 	static class TestDataSourceConfiguration {
 

spring-boot-dependencies/pom.xml

@@ -54,6 +54,7 @@
 		<commons-beanutils.version>1.9.2</commons-beanutils.version>
 		<commons-collections.version>3.2.1</commons-collections.version>
 		<commons-dbcp.version>1.4</commons-dbcp.version>
+		<commons-dbcp2.version>2.0.1</commons-dbcp2.version>
 		<commons-digester.version>2.1</commons-digester.version>
 		<commons-pool.version>1.6</commons-pool.version>
 		<commons-pool2.version>2.2</commons-pool2.version>
@@ -484,6 +485,11 @@
 				<artifactId>commons-collections</artifactId>
 				<version>${commons-collections.version}</version>
 			</dependency>
+			<dependency>
+				<groupId>org.apache.commons</groupId>
+				<artifactId>commons-dbcp2</artifactId>
+				<version>${commons-dbcp2.version}</version>
+			</dependency>
 			<dependency>
 				<groupId>commons-dbcp</groupId>
 				<artifactId>commons-dbcp</artifactId>

spring-boot-docs/src/main/asciidoc/spring-boot-features.adoc

@@ -1249,7 +1249,9 @@ Production database connections can also be auto-configured using a pooling
 
 * We prefer the Tomcat pooling `DataSource` for its performance and concurrency, so if
   that is available we always choose it.
-* If commons-dbcp is available we will use that, but we don't recommend it in production.
+* If HikariCP is available we will use it
+* If Commons DBCP is available we will use it, but we don't recommend it in production.
+* Lastly, if Commons DBCP2 is available we will use it
 
 If you use the `spring-boot-starter-jdbc` or `spring-boot-starter-data-jpa`
 ``starter POMs'' you will automcatically get a dependency to `tomcat-jdbc`.