/*
* Copyright 2016-2019 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.cloud.task.batch.listener.support;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.support.MessageBuilder;
import org.springframework.util.Assert;
/**
* Utility class that sends batch job listener payloads to the notification channel.
*
* @param <P> payload type
* @author Glenn Renfro
*/
public class MessagePublisher<P> {
private final MessageChannel listenerEventsChannel;
public MessagePublisher(MessageChannel listenerEventsChannel) {
Assert.notNull(listenerEventsChannel, "listenerEventsChannel must not be null");
this.listenerEventsChannel = listenerEventsChannel;
}
public final void publish(P payload) {
if (payload instanceof Message) {
this.publishMessage((Message<?>) payload);
}
else {
Message<P> message = MessageBuilder.withPayload(payload).build();
this.listenerEventsChannel.send(message);
}
}
private void publishMessage(Message<?> message) {
this.listenerEventsChannel.send(message);
}
public void publishWithThrowableHeader(P payload, String header) {
Message<P> message = MessageBuilder.withPayload(payload)
.setHeader(BatchJobHeaders.BATCH_EXCEPTION, header).build();
publishMessage(message);
}
}
