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。
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。
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。
