redis实现订单自动过期功能的源码分享

文章背景

我们的目的是在用户下单后，规定指定时间后自动将订单设置为“已过期”，不能再发起支付。

（学习视频分享：redis视频教程）

思路：

结合Redis的订阅、发布和键空间通知机制（Keyspace Notifications）进行实现。

配置redis.confg

notify-keyspace-events选项默认是不启用，改为notify-keyspace-events “Ex”。重启生效，索引位i的库，每当有过期的元素被删除时，向**keyspace@:expired**频道发送通知。
E表示键事件通知，所有通知以__keyevent@__:expired为前缀；
x表示过期事件，每当有过期被删除时发送。

与SpringBoot进行集成

1、注册JedisConnectionFactory

import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.RedisPassword;
import org.springframework.data.redis.connection.RedisStandaloneConfiguration;
import org.springframework.data.redis.connection.jedis.JedisConnectionFactory;

import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;

@Configuration
public class RedisConfig {
	
	@Value("${redis.pool.maxTotal}")
	private Integer maxTotal;
	
	@Value("${redis.pool.minIdle}")
	private Integer minIdle;
	
	@Value("${redis.pool.maxIdle}")
	private Integer maxIdle;
	
	@Value("${redis.pool.maxWaitMillis}")
	private Integer maxWaitMillis;
	
	@Value("${redis.url}")
	private String redisUrl;
	
	@Value("${redis.port}")
	private Integer redisPort;
	
	@Value("${redis.timeout}")
	private Integer redisTimeout;
	
	@Value("${redis.password}")
	private String redisPassword;
	
	@Value("${redis.db.payment}")
	private Integer paymentDataBase;
	
	private JedisPoolConfig jedisPoolConfig() {
		JedisPoolConfig config = new JedisPoolConfig();
		config.setMaxTotal(maxTotal);
		config.setMinIdle(minIdle);
		config.setMaxIdle(maxIdle);
		config.setMaxWaitMillis(maxWaitMillis);
		return config;
	}
	
	@Bean
	public JedisPool jedisPool() {
		JedisPoolConfig config = this.jedisPoolConfig();
		JedisPool jedisPool = new JedisPool(config, redisUrl, redisPort, redisTimeout, redisPassword);
		return jedisPool;
	}
	
	@Bean(name = "jedisConnectionFactory")
	public JedisConnectionFactory jedisConnectionFactory() {
		RedisStandaloneConfiguration redisStandaloneConfiguration = new RedisStandaloneConfiguration();
		redisStandaloneConfiguration.setDatabase(paymentDataBase);
		redisStandaloneConfiguration.setHostName(redisUrl);
		redisStandaloneConfiguration.setPassword(RedisPassword.of(redisPassword));
		redisStandaloneConfiguration.setPort(redisPort);

		return new JedisConnectionFactory(redisStandaloneConfiguration);
	}
}

2、注册监听器

import org.springframework.data.redis.connection.Message;
import org.springframework.data.redis.connection.MessageListener;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

@Service(value ="paymentListener")
public class PaymentListener implements MessageListener {

	@Override
	@Transactional
	public void onMessage(Message message, byte[] pattern) {
		// 过期事件处理流程
	}

}

3、配置订阅对象

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.AutoConfigureAfter;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.jedis.JedisConnectionFactory;
import org.springframework.data.redis.listener.PatternTopic;
import org.springframework.data.redis.listener.RedisMessageListenerContainer;
import org.springframework.data.redis.listener.adapter.MessageListenerAdapter;

@Configuration
@AutoConfigureAfter(value = RedisConfig.class)
public class PaymentListenerConfig {
	
	@Autowired
	@Qualifier(value = "paymentListener")
	private PaymentListener paymentListener;
	
	@Autowired
	@Qualifier(value = "paymentListener")
	private JedisConnectionFactory connectionFactory;
	
	@Value("${redis.db.payment}")
	private Integer paymentDataBase;
	
	@Bean
	RedisMessageListenerContainer redisMessageListenerContainer(MessageListenerAdapter listenerAdapter) {
        RedisMessageListenerContainer container = new RedisMessageListenerContainer();
        container.setConnectionFactory(connectionFactory);
        // 监听paymentDataBase 库的过期事件
        String subscribeChannel = "__keyevent@" + paymentDataBase + "__:expired";
        container.addMessageListener(listenerAdapter, new PatternTopic(subscribeChannel));
        return container;
	}
	
	@Bean
    MessageListenerAdapter listenerAdapter() {
        return new MessageListenerAdapter(paymentListener);
    }
}

paymentDataBase 库元素过期后就会跳入PaymentListener 的onMessage(Message message, byte[] pattern)方法。