Take care registering DataSourceInitializer

The DataSourceInitializer is instantiated early by the
DataSourceInitializerPostProcessor, so it has to live in
isolation (in its own @Configuration) to prevent early
instantiation of the DataSourceAutoConfiguration.

Fixes gh-1166

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

@@ -58,17 +58,6 @@ public class DataSourceAutoConfiguration {
 
 	public static final String CONFIGURATION_PREFIX = "spring.datasource";
 
-	@Autowired
-	private DataSourceProperties properties;
-
-	@Autowired(required = false)
-	private DataSource dataSource;
-
-	@Bean
-	public DataSourceInitializer dataSourceAutoConfigurationInitializer() {
-		return new DataSourceInitializer();
-	}
-
 	/**
 	 * Determines if the {@code dataSource} being used by Spring was created from
 	 * {@link EmbeddedDataSourceConfiguration}.
@@ -93,6 +82,16 @@ public class DataSourceAutoConfiguration {
 
 	}
 
+	@Configuration
+	@ConditionalOnMissingBean(DataSourceInitializer.class)
+	protected static class DataSourceInitializerConfiguration {
+
+		@Bean
+		public DataSourceInitializer dataSourceInitializer() {
+			return new DataSourceInitializer();
+		}
+	}
+
 	@Conditional(DataSourceAutoConfiguration.NonEmbeddedDatabaseCondition.class)
 	@ConditionalOnMissingBean(DataSource.class)
 	protected static class NonEmbeddedConfiguration {

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

@@ -24,8 +24,13 @@ import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 import org.springframework.boot.autoconfigure.PropertyPlaceholderAutoConfiguration;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.boot.test.EnvironmentTestUtils;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Primary;
 import org.springframework.jdbc.core.JdbcOperations;
 import org.springframework.jdbc.core.JdbcTemplate;
 import org.springframework.util.ClassUtils;
@@ -67,6 +72,19 @@ public class DataSourceInitializerTests {
 		assertEquals(0, this.context.getBeanNamesForType(DataSource.class).length);
 	}
 
+	@Test
+	public void testTwoDataSources() throws Exception {
+		EnvironmentTestUtils.addEnvironment(this.context,
+				"datasource.one.url=jdbc:hsqldb:mem:/one",
+				"datasource.one.driverClassName=org.hsqldb.Driver",
+				"datasource.two.url=jdbc:hsqldb:mem:/two",
+				"datasource.two.driverClassName=org.hsqldb.Driver");
+		this.context.register(TwoDataSources.class, DataSourceInitializer.class,
+				PropertyPlaceholderAutoConfiguration.class, DataSourceProperties.class);
+		this.context.refresh();
+		assertEquals(2, this.context.getBeanNamesForType(DataSource.class).length);
+	}
+
 	@Test
 	public void testDataSourceInitialized() throws Exception {
 		EnvironmentTestUtils.addEnvironment(this.context,
@@ -125,4 +143,23 @@ public class DataSourceInitializerTests {
 				template.queryForObject("SELECT COUNT(*) from SPAM", Integer.class));
 	}
 
+	@Configuration
+	@EnableConfigurationProperties
+	protected static class TwoDataSources {
+
+		@Bean
+		@Primary
+		@ConfigurationProperties(prefix = "datasource.one")
+		public DataSource oneDataSource() {
+			return DataSourceBuilder.create().build();
+		}
+
+		@Bean
+		@ConfigurationProperties(prefix = "datasource.two")
+		public DataSource twoDataSource() {
+			return DataSourceBuilder.create().build();
+		}
+
+	}
+
 }