Allow null method for getTransactionAttribute

Update MatchAlwaysTransactionAttributeSource.getTransactionAttribute
to allow a null method argument. Passing a null method is not
recommended and is not indicated as valid in the Javadoc, however,
this was allowed in previous versions of Spring.

Issue: SPR-11048

Author: Phillip Webb

spring-core/src/main/java/org/springframework/util/ClassUtils.java

@@ -778,8 +778,12 @@ public static Method getMostSpecificMethod(Method method, Class<?> targetClass)
 	 * @return {@code true} if the method can be considered as user-declared; [@code false} otherwise
 	 */
 	public static boolean isUserLevelMethod(Method method) {
-		return (method.isBridge() ||
-				(!method.isSynthetic() && !method.getDeclaringClass().getName().equals("groovy.lang.GroovyObject")));
+		Assert.notNull(method, "Method must not be null");
+		return (method.isBridge() || (!method.isSynthetic() && !isGroovyObjectMethod(method)));
+	}
+
+	private static boolean isGroovyObjectMethod(Method method) {
+		return method.getDeclaringClass().getName().equals("groovy.lang.GroovyObject");
 	}
 
 	/**

spring-tx/src/main/java/org/springframework/transaction/interceptor/MatchAlwaysTransactionAttributeSource.java

@@ -53,7 +53,7 @@ public void setTransactionAttribute(TransactionAttribute transactionAttribute) {
 
 	@Override
 	public TransactionAttribute getTransactionAttribute(Method method, Class<?> targetClass) {
-		return (ClassUtils.isUserLevelMethod(method) ? this.transactionAttribute : null);
+		return (method == null || ClassUtils.isUserLevelMethod(method) ? this.transactionAttribute : null);
 	}
 
 

spring-tx/src/test/java/org/springframework/transaction/interceptor/TransactionAttributeSourceTests.java

@@ -54,6 +54,16 @@ public void testMatchAlwaysTransactionAttributeSource() throws Exception {
 		assertTrue(TransactionDefinition.PROPAGATION_SUPPORTS == ta.getPropagationBehavior());
 	}
 
+	@Test
+	public void testMatchAlwaysTransactionAttributeSourceWithNulls() throws Exception {
+		MatchAlwaysTransactionAttributeSource tas = new MatchAlwaysTransactionAttributeSource();
+		TransactionDefinition definition = tas.getTransactionAttribute(null, null);
+		assertEquals(TransactionDefinition.PROPAGATION_REQUIRED, definition.getPropagationBehavior());
+		assertEquals(TransactionDefinition.ISOLATION_DEFAULT, definition.getIsolationLevel());
+		assertEquals(TransactionDefinition.TIMEOUT_DEFAULT, definition.getTimeout());
+		assertFalse(definition.isReadOnly());
+	}
+
 	@SuppressWarnings("unchecked")
 	@Ignore // no longer works now that setMethodMap has been parameterized
 	@Test