5.常用技术（二）

1.发布订阅

作用：当使用银行卡消费时，银行往往会通过微信或者短信等通知用户这笔交易

1.配置监听者，需实现MessageListener接口,并注入在applicationContext.xml中

package com.ssm.chapter19.redis.listener;

import org.springframework.data.redis.connection.Message;
import org.springframework.data.redis.connection.MessageListener;
import org.springframework.data.redis.core.RedisTemplate;

public class RedisMessageListener implements MessageListener {
	
	private RedisTemplate redisTemplate;

	@Override
	public void onMessage(Message message, byte[] bytes) {
		// 配置如何获取消息
		byte[] body = message.getBody();
		// 使用值序列化器转换
		String msgBody = (String) getRedisTemplate().getValueSerializer().deserialize(body);
		System.err.println(msgBody);
		
		// 配置如何获取渠道
		byte[] channel = message.getChannel();
		// 使用字符串序列化器转换
		String channelStr = (String) getRedisTemplate().getStringSerializer().deserialize(channel);
		System.err.println(channelStr);
		// 渠道名称转换
		String bytesStr = new String(bytes);
		System.err.println(bytesStr);
	}

	public RedisTemplate getRedisTemplate() {
		return redisTemplate;
	}

	public void setRedisTemplate(RedisTemplate redisTemplate) {
		this.redisTemplate = redisTemplate;
	}
}

<bean id="redisMsgListener"
		class="com.ssm.chapter19.redis.listener.RedisMessageListener">
		<property name="redisTemplate" ref="redisTemplate" />
	</bean>

2.在applicationContext.xml中配置消息监听个容器，里面存放redis连接工厂，线程池，监听者，渠道

<?xml version='1.0' encoding='UTF-8' ?>
<!-- was: <?xml version="1.0" encoding="UTF-8"?> -->
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
	xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
	xmlns:context="http://www.springframework.org/schema/context"
	xsi:schemaLocation="http://www.springframework.org/schema/beans 
	   http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
       http://www.springframework.org/schema/aop 
       http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
       http://www.springframework.org/schema/tx 
       http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
       http://www.springframework.org/schema/context 
       http://www.springframework.org/schema/context/spring-context-4.0.xsd">
	<bean id="poolConfig" class="redis.clients.jedis.JedisPoolConfig">
		<property name="maxIdle" value="50" />
		<property name="maxTotal" value="100" />
		<property name="maxWaitMillis" value="20000" />
	</bean>

	<bean id="stringRedisSerializer"
		class="org.springframework.data.redis.serializer.StringRedisSerializer" />

	<bean id="connectionFactory"
		class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory">
		<property name="hostName" value="localhost" />
		<property name="port" value="6379" />
		<property name="poolConfig" ref="poolConfig" />
	</bean>

	<bean id="redisTemplate" class="org.springframework.data.redis.core.RedisTemplate">
		<property name="connectionFactory" ref="connectionFactory" />
		<property name="defaultSerializer" ref="stringRedisSerializer" />
		<property name="keySerializer" ref="stringRedisSerializer" />
		<property name="valueSerializer" ref="stringRedisSerializer" />
	</bean>

	<bean id="redisMsgListener"
		class="com.ssm.chapter19.redis.listener.RedisMessageListener">
		<property name="redisTemplate" ref="redisTemplate" />
	</bean>

	<bean id="topicContainer"
		class="org.springframework.data.redis.listener.RedisMessageListenerContainer"
		destroy-method="destroy">		
					<!--Redis连接工厂 -->
		<property name="connectionFactory" ref="connectionFactory" />		
					<!--线程池，等待消息任务 -->
		<property name="taskExecutor">
			<bean
				class="org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler">
				<property name="poolSize" value="2" />
			</bean>
		</property>		
					<!--消息监听Map -->
		<property name="messageListeners">
			<map>
					<!--配置监听者，key-ref和bean id定义一致 -->
				<entry key-ref="redisMsgListener">
					<!--渠道 -->
					<bean class="org.springframework.data.redis.listener.ChannelTopic">
						<constructor-arg value="chat" />
					</bean>
				</entry>
			</map>
		</property>
	</bean>
</beans>

3.发送消息

ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
		RedisTemplate redisTemplate = applicationContext.getBean(RedisTemplate.class);
		String channel = "chat";
		//向渠道chat发送消息
		redisTemplate.convertAndSend(channel, "I am lazy!!");

2.流水线(pipelined)

1. 作用：pipeline适用于批处理

2.先配置Jedis连接池，jedis是redis的客户端

private static JedisPool getPool() {
		JedisPoolConfig poolCfg = new JedisPoolConfig();
		// 最大空闲数
		poolCfg.setMaxIdle(50);
		// 最大连接数
		poolCfg.setMaxTotal(100);
		// 最大等待毫秒数
		poolCfg.setMaxWaitMillis(20000);
		// 使用配置创建连接池
		JedisPool pool = new JedisPool(poolCfg, "localhost");
		// 从连接池中获取单个连接
		Jedis jedis = pool.getResource();
		// 如果需密码
		// jedis.auth("password");
		return pool;
	}

public static void testJedisPipeline() {
        //获取jedis连接池
		JedisPool pool = getPool();
		// 从连接池中获取单个连接
		Jedis jedis = pool.getResource();
		long start = System.currentTimeMillis();
		// 开启流水线
		Pipeline pipeline = jedis.pipelined();
		// 这里测试10万条的读写2个操作
		for (int i = 0; i < 100000; i++) {
			int j = i + 1;
			pipeline.set("pipeline_key_" + j, "pipeline_value_" + j);
			pipeline.get("pipeline_key_" + j);
		}
		// pipeline.sync();//这里只执行同步，但是不返回结果
		
		// pipeline.syncAndReturnAll();将返回执行过的命令返回的List列表结果
		List result = pipeline.syncAndReturnAll();
		
		long end = System.currentTimeMillis();
		// 计算耗时
		System.err.println("耗时：" + (end - start) + "毫秒");
	}