Add warning log

Author: backpaper0

doma-spring-boot-autoconfigure/src/main/java/org/seasar/doma/boot/autoconfigure/DomaAutoConfiguration.java

@@ -17,6 +17,8 @@
 
 import javax.sql.DataSource;
 
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import org.seasar.doma.boot.DomaPersistenceExceptionTranslator;
 import org.seasar.doma.boot.TryLookupEntityListenerProvider;
 import org.seasar.doma.boot.autoconfigure.DomaProperties.DialectType;
@@ -65,6 +67,8 @@
 @AutoConfigureAfter(DataSourceAutoConfiguration.class)
 public class DomaAutoConfiguration {
 
+	private static final Log logger = LogFactory.getLog(DomaAutoConfiguration.class);
+
 	@Autowired
 	private DomaProperties domaProperties;
 
@@ -100,6 +104,10 @@ public Dialect dialect(Environment environment) {
 				break;
 			}
 		}
+		if (logger.isWarnEnabled()) {
+			logger.warn(
+					"StandardDialect was selected because no explicit configuration and it is not possible to guess from 'spring.datasource.url property'");
+		}
 		return new StandardDialect();
 	}