Added DriverClassNameProvider used for providing jdbc driver class based on jdbc url

Uses known databases from org.flywaydb.core.internal.util.jdbc.DriverDataSource

Fixes gh-824, fixes gh-809

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

@@ -20,12 +20,15 @@ import org.springframework.beans.factory.BeanClassLoaderAware;
 import org.springframework.beans.factory.BeanCreationException;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 import org.springframework.util.StringUtils;
 
 /**
  * Base class for configuration of a database pool.
  * 
  * @author Dave Syer
+ * @author Maciej Walkowiak
  * @since 1.1.0
  */
 @ConfigurationProperties(prefix = DataSourceAutoConfiguration.CONFIGURATION_PREFIX)
@@ -53,6 +56,8 @@ public class DataSourceProperties implements BeanClassLoaderAware, InitializingB
 
 	private EmbeddedDatabaseConnection embeddedDatabaseConnection = EmbeddedDatabaseConnection.NONE;
 
+	private DriverClassNameProvider driverClassNameProvider = new DriverClassNameProvider();
+
 	@Override
 	public void setBeanClassLoader(ClassLoader classLoader) {
 		this.classLoader = classLoader;
@@ -64,11 +69,22 @@ public class DataSourceProperties implements BeanClassLoaderAware, InitializingB
 				.get(this.classLoader);
 	}
 
-	public String getDriverClassName() {
+	protected String getDriverClassName() {
 		if (StringUtils.hasText(this.driverClassName)) {
+			Assert.state(ClassUtils.isPresent(this.driverClassName, null),
+					"Cannot load driver class: " + this.driverClassName);
 			return this.driverClassName;
 		}
-		String driverClassName = this.embeddedDatabaseConnection.getDriverClassName();
+		String driverClassName = null;
+
+		if (StringUtils.hasText(this.url)) {
+			driverClassName = this.driverClassNameProvider.getDriverClassName(this.url);
+		}
+
+		if (!StringUtils.hasText(driverClassName)) {
+			driverClassName = this.embeddedDatabaseConnection.getDriverClassName();
+		}
+
 		if (!StringUtils.hasText(driverClassName)) {
 			throw new BeanCreationException(
 					"Cannot determine embedded database driver class for database type "
@@ -173,5 +189,4 @@ public class DataSourceProperties implements BeanClassLoaderAware, InitializingB
 	public ClassLoader getClassLoader() {
 		return this.classLoader;
 	}
-
 }

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

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2012-2014 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.HashMap;
+import java.util.Map;
+
+import org.springframework.util.Assert;
+
+/**
+ * Provides JDBC driver class name for given JDBC URL.
+ *
+ * @author Maciej Walkowiak
+ * @since 1.1.0
+ */
+class DriverClassNameProvider {
+
+	private static final String JDBC_URL_PREFIX = "jdbc";
+
+	private static final Map<String, String> driverMap = new HashMap<String, String>() {
+		{
+			put("db2", "com.ibm.db2.jcc.DB2Driver");
+			put("derby", "org.apache.derby.jdbc.EmbeddedDriver");
+			put("h2", "org.h2.Driver");
+			put("hsqldb", "org.hsqldb.jdbcDriver");
+			put("sqlite", "org.sqlite.JDBC");
+			put("mysql", "com.mysql.jdbc.Driver");
+			put("mariadb", "org.mariadb.jdbc.Driver");
+			put("google", "com.google.appengine.api.rdbms.AppEngineDriver");
+			put("oracle", "oracle.jdbc.OracleDriver");
+			put("postgresql", "org.postgresql.Driver");
+			put("jtds", "net.sourceforge.jtds.jdbc.Driver");
+			put("sqlserver", "com.microsoft.sqlserver.jdbc.SQLServerDriver");
+
+		}
+	};
+
+	/**
+	 * Used to find JDBC driver class name based on given JDBC URL
+	 *
+	 * @param jdbcUrl JDBC URL
+	 * @return driver class name or null if not found
+	 */
+	String getDriverClassName(final String jdbcUrl) {
+		Assert.notNull(jdbcUrl, "JDBC URL cannot be null");
+
+		if (!jdbcUrl.startsWith(JDBC_URL_PREFIX)) {
+			throw new IllegalArgumentException("JDBC URL should start with '"
+					+ JDBC_URL_PREFIX + "'");
+		}
+
+		String urlWithoutPrefix = jdbcUrl.substring(JDBC_URL_PREFIX.length());
+		String result = null;
+
+		for (Map.Entry<String, String> driver : driverMap.entrySet()) {
+			if (urlWithoutPrefix.startsWith(":" + driver.getKey() + ":")) {
+				result = driver.getValue();
+
+				break;
+			}
+		}
+
+		return result;
+	}
+
+}

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

@@ -95,6 +95,8 @@ public class DataSourceAutoConfigurationTests {
 
 	@Test(expected = BeanCreationException.class)
 	public void testBadUrl() throws Exception {
+		EnvironmentTestUtils.addEnvironment(this.context,
+				"spring.datasource.url:jdbc:not-going-to-work");
 		EmbeddedDatabaseConnection.override = EmbeddedDatabaseConnection.NONE;
 		this.context.register(DataSourceAutoConfiguration.class,
 				PropertyPlaceholderAutoConfiguration.class);
@@ -104,6 +106,9 @@ public class DataSourceAutoConfigurationTests {
 
 	@Test(expected = BeanCreationException.class)
 	public void testBadDriverClass() throws Exception {
+		EnvironmentTestUtils.addEnvironment(this.context,
+				"spring.datasource.driverClassName:org.none.jdbcDriver",
+				"spring.datasource.url:jdbc:hsqldb:mem:testdb");
 		EmbeddedDatabaseConnection.override = EmbeddedDatabaseConnection.NONE;
 		this.context.register(DataSourceAutoConfiguration.class,
 				PropertyPlaceholderAutoConfiguration.class);

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

@@ -0,0 +1,31 @@
+package org.springframework.boot.autoconfigure.jdbc;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * Tests for {@link DataSourceProperties}.
+ *
+ * @author Maciej Walkowiak
+ */
+public class DataSourcePropertiesTests {
+
+	@Test
+	public void correctDriverClassNameFromJdbcUrlWhenDriverClassNameNotDefined() {
+		DataSourceProperties configuration = new DataSourceProperties();
+		configuration.setUrl("jdbc:mysql://mydb");
+		String driverClassName = configuration.getDriverClassName();
+		assertEquals(driverClassName, "com.mysql.jdbc.Driver");
+	}
+
+	@Test
+	public void driverClassNameFromDriverClassNamePropertyWhenDefined() {
+		DataSourceProperties configuration = new DataSourceProperties();
+		configuration.setUrl("jdbc:mysql://mydb");
+		configuration.setDriverClassName("my.driver.ClassName");
+		String driverClassName = configuration.getDriverClassName();
+		assertEquals(driverClassName, "my.driver.ClassName");
+	}
+
+}

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

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2012-2014 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 org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+/**
+ * Tests for {@link DriverClassNameProvider}.
+ *
+ * @author Maciej Walkowiak
+ */
+public class DriverClassNameProviderTest {
+    private DriverClassNameProvider driverClassNameProvider = new DriverClassNameProvider();
+
+    @Test
+    public void testGettingClassNameForKnownDatabase() {
+        String driverClassName = driverClassNameProvider.getDriverClassName("jdbc:postgresql://hostname/dbname");
+
+        assertEquals("org.postgresql.Driver", driverClassName);
+    }
+
+    @Test
+    public void testReturnsNullForUnknownDatabase() {
+        String driverClassName = driverClassNameProvider.getDriverClassName("jdbc:unknowndb://hostname/dbname");
+
+        assertNull(driverClassName);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testFailureOnNullJdbcUrl() {
+        driverClassNameProvider.getDriverClassName(null);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testFailureOnMalformedJdbcUrl() {
+        driverClassNameProvider.getDriverClassName("malformed:url");
+    }
+}