Redis实现订单自动过期功能

刺骨的言语ヽ痛彻心扉 2022-03-19 10:46 217阅读 0赞

## Redis实现订单自动过期功能 ##

### 前言 ###

用户下单后，规定XX分钟后自动设置为“已过期”，不能再发起支付。项目类似此类"过期"的需求，笔者提供一种使用Redis的解决思路，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。