Spy.java

/*
 * Copyright 2015 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
 *
 *      http://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.cloud.stream.binder;

/**
 * Represents an out-of-band connection to the underlying middleware,
 * so that tests can check that some messages actually do (or do not)
 * transit through it.
 *
 * @author Eric Bottard
 */
public interface Spy {

	Object receive(boolean expectNull) throws Exception;
}