Fix DataSourceUtils inconsistent exception handling

Align IllegalStateException with SQLException handling and propagate
the original exception.

See gh-28669

Co-authored-by: Christoph Mies <chr.mi@web.de>

spring-jdbc/src/main/java/org/springframework/jdbc/CannotGetJdbcConnectionException.java

@@ -48,4 +48,7 @@ public class CannotGetJdbcConnectionException extends DataAccessResourceFailureE
 		super(msg, ex);
 	}
 
+	public CannotGetJdbcConnectionException(String msg, IllegalStateException ex) {
+		super(msg, ex);
+	}
 }

spring-jdbc/src/main/java/org/springframework/jdbc/datasource/DataSourceUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -83,7 +83,7 @@ public abstract class DataSourceUtils {
 			throw new CannotGetJdbcConnectionException("Failed to obtain JDBC Connection", ex);
 		}
 		catch (IllegalStateException ex) {
-			throw new CannotGetJdbcConnectionException("Failed to obtain JDBC Connection: " + ex.getMessage());
+			throw new CannotGetJdbcConnectionException("Failed to obtain JDBC Connection", ex);
 		}
 	}
 

spring-jdbc/src/test/java/org/springframework/jdbc/datasource/DataSourceUtilsTests.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2002-2022 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
+ *
+ *      https://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.jdbc.datasource;
+
+import java.sql.SQLException;
+
+import javax.sql.DataSource;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.jdbc.CannotGetJdbcConnectionException;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.mockito.BDDMockito.when;
+import static org.mockito.Mockito.mock;
+
+/**
+ * @author Kevin Schoenfeld
+ * @see org.springframework.jdbc.datasource.DataSourceUtilsTests
+ * @since 21.06.2022
+ */
+
+class DataSourceUtilsTests {
+
+	@Test
+	void testConnectionNotAcquiredExceptionIsPropagated() throws SQLException {
+		final DataSource dataSource = mock(DataSource.class);
+		when(dataSource.getConnection()).thenReturn(null);
+
+		assertThatThrownBy(() -> DataSourceUtils.getConnection(dataSource))
+				.isInstanceOf(CannotGetJdbcConnectionException.class)
+				.hasMessageStartingWith("Failed to obtain JDBC Connection")
+				.hasCauseInstanceOf(IllegalStateException.class);
+	}
+
+	@Test
+	void testConnectionSQLExceptionIsPropagated() throws SQLException {
+		final DataSource dataSource = mock(DataSource.class);
+		when(dataSource.getConnection()).thenThrow(new SQLException("my dummy exception"));
+
+		assertThatThrownBy(() -> DataSourceUtils.getConnection(dataSource))
+				.isInstanceOf(CannotGetJdbcConnectionException.class)
+				.hasMessageStartingWith("Failed to obtain JDBC Connection")
+				.hasCauseInstanceOf(SQLException.class);
+	}
+}