org.springframework.data.redis.listener.KeyspaceEventMessageListener Maven / Gradle / Ivy
/*
* Copyright 2015-2018 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.data.redis.listener;
import java.util.Properties;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.data.redis.connection.Message;
import org.springframework.data.redis.connection.MessageListener;
import org.springframework.data.redis.connection.RedisConnection;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.ObjectUtils;
import org.springframework.util.StringUtils;
/**
* Base {@link MessageListener} implementation for listening to Redis keyspace notifications.
*
* @author Christoph Strobl
* @author Mark Paluch
* @since 1.7
*/
public abstract class KeyspaceEventMessageListener implements MessageListener, InitializingBean, DisposableBean {
private static final Topic TOPIC_ALL_KEYEVENTS = new PatternTopic("__keyevent@*");
private final RedisMessageListenerContainer listenerContainer;
private String keyspaceNotificationsConfigParameter = "EA";
/**
* Creates new {@link KeyspaceEventMessageListener}.
*
* @param listenerContainer must not be {@literal null}.
*/
public KeyspaceEventMessageListener(RedisMessageListenerContainer listenerContainer) {
Assert.notNull(listenerContainer, "RedisMessageListenerContainer to run in must not be null!");
this.listenerContainer = listenerContainer;
}
/*
* (non-Javadoc)
* @see org.springframework.data.redis.connection.MessageListener#onMessage(org.springframework.data.redis.connection.Message, byte[])
*/
@Override
public void onMessage(Message message, @Nullable byte[] pattern) {
if (message == null || ObjectUtils.isEmpty(message.getChannel()) || ObjectUtils.isEmpty(message.getBody())) {
return;
}
doHandleMessage(message);
}
/**
* Handle the actual message
*
* @param message never {@literal null}.
*/
protected abstract void doHandleMessage(Message message);
/**
* Initialize the message listener by writing requried redis config for {@literal notify-keyspace-events} and
* registering the listener within the container.
*/
public void init() {
if (StringUtils.hasText(keyspaceNotificationsConfigParameter)) {
RedisConnection connection = listenerContainer.getConnectionFactory().getConnection();
try {
Properties config = connection.getConfig("notify-keyspace-events");
if (!StringUtils.hasText(config.getProperty("notify-keyspace-events"))) {
connection.setConfig("notify-keyspace-events", keyspaceNotificationsConfigParameter);
}
} finally {
connection.close();
}
}
doRegister(listenerContainer);
}
/**
* Register instance within the container.
*
* @param container never {@literal null}.
*/
protected void doRegister(RedisMessageListenerContainer container) {
listenerContainer.addMessageListener(this, TOPIC_ALL_KEYEVENTS);
}
/*
* (non-Javadoc)
* @see org.springframework.beans.factory.DisposableBean#destroy()
*/
@Override
public void destroy() throws Exception {
listenerContainer.removeMessageListener(this);
}
/**
* Set the configuration string to use for {@literal notify-keyspace-events}.
*
* @param keyspaceNotificationsConfigParameter can be {@literal null}.
* @since 1.8
*/
public void setKeyspaceNotificationsConfigParameter(String keyspaceNotificationsConfigParameter) {
this.keyspaceNotificationsConfigParameter = keyspaceNotificationsConfigParameter;
}
/*
* (non-Javadoc)
* @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet()
*/
@Override
public void afterPropertiesSet() throws Exception {
init();
}
}