Introduce withoutTransaction factory method on TransactionOperations

Closes gh-23198

spring-tx/src/main/java/org/springframework/transaction/support/TransactionOperations.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -44,4 +44,23 @@ public interface TransactionOperations {
 	@Nullable
 	<T> T execute(TransactionCallback<T> action) throws TransactionException;
 
+
+	/**
+	 * Return an implementation of the {@code TransactionOperations} interface which
+	 * executes a given {@link TransactionCallback} without an actual transaction.
+	 * <p>Useful for testing: The behavior is equivalent to running with a
+	 * transaction manager with no actual transaction (PROPAGATION_SUPPORTS)
+	 * and no synchronization (SYNCHRONIZATION_NEVER).
+	 * <p>For a {@link TransactionOperations} implementation with actual
+	 * transaction processing, use {@link TransactionTemplate} with an appropriate
+	 * {@link org.springframework.transaction.PlatformTransactionManager}.
+	 * @since 5.2
+	 * @see org.springframework.transaction.TransactionDefinition#PROPAGATION_SUPPORTS
+	 * @see AbstractPlatformTransactionManager#SYNCHRONIZATION_NEVER
+	 * @see TransactionTemplate
+	 */
+	static TransactionOperations withoutTransaction() {
+		return WithoutTransactionOperations.INSTANCE;
+	};
+
 }

spring-tx/src/main/java/org/springframework/transaction/support/WithoutTransactionOperations.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2002-2019 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.transaction.support;
+
+import org.springframework.lang.Nullable;
+import org.springframework.transaction.TransactionException;
+
+/**
+ * A {@link TransactionOperations} implementation which executes a given
+ * {@link TransactionCallback} without an actual transaction.
+ *
+ * @author Juergen Hoeller
+ * @since 5.2
+ * @see TransactionOperations#withoutTransaction()
+ */
+final class WithoutTransactionOperations implements TransactionOperations {
+
+	static final WithoutTransactionOperations INSTANCE = new WithoutTransactionOperations();
+
+	private WithoutTransactionOperations() {
+	}
+
+	@Override
+	@Nullable
+	public <T> T execute(TransactionCallback<T> action) throws TransactionException {
+		return action.doInTransaction(new SimpleTransactionStatus(false));
+	}
+
+}