SpringBoot如何监控Redis中某个Key的变化(自定义监听器)

目录

• SpringBoot 监控Redis中某个Key的变化

• 1.声明
• 2.基本理念
• 3.实现和创建监听
• 4.基本demo的其他配置
• 5.基本测试
• 6.小结一下

• 原理
• 示例

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);
	}

import java.nio.charset.Charset;
import java.util.Properties;
import org.springframework.data.redis.connection.Message;
import org.springframework.data.redis.connection.MessageListener;
import org.springframework.data.redis.connection.RedisConnection;
import org.springframework.data.redis.listener.KeyspaceEventMessageListener;
import org.springframework.data.redis.listener.PatternTopic;
import org.springframework.data.redis.listener.RedisMessageListenerContainer;
import org.springframework.data.redis.listener.Topic;
import org.springframework.util.StringUtils;
/**
 * 
 * @author hy
 * @createTime 2021-05-01 08:53:19
 * @description 期望是可以监听某个key的变化，而不是失效
 *
 */
public class RedisKeyChangeListener implements MessageListener/* extends KeyspaceEventMessageListener */ {
	private final String listenerKeyName; // 监听的key的名称
	private static final Topic TOPIC_ALL_KEYEVENTS = new PatternTopic("__keyevent@*"); //表示只监听所有的key 
	private static final Topic TOPIC_KEYEVENTS_SET = new PatternTopic("__keyevent@0__:set"); //表示只监听所有的key
	private static final Topic TOPIC_KEYNAMESPACE_NAME = new PatternTopic("__keyspace@0__:myKey"); // 不生效
	// 监控
	//private static final Topic TOPIC_KEYEVENTS_NAME_SET_USELESS = new PatternTopic("__keyevent@0__:set myKey");
	private String keyspaceNotificationsConfigParameter = "KEA";
	public RedisKeyChangeListener(RedisMessageListenerContainer listenerContainer, String listenerKeyName) {
		this.listenerKeyName = listenerKeyName;
		initAndSetRedisConfig(listenerContainer);
	}
	public void initAndSetRedisConfig(RedisMessageListenerContainer listenerContainer) {
		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();
			}
		}
		// 注册消息监听
		listenerContainer.addMessageListener(this, TOPIC_KEYNAMESPACE_NAME);
	}
	@Override
	public void onMessage(Message message, byte[] pattern) {
		System.out.println("key发生变化===》" + message);
		byte[] body = message.getBody();
		String string = new String(body, Charset.forName("utf-8"));
		System.out.println(string);
	}
}

@Configuration
@PropertySource(value = "redis.properties")
@ConditionalOnClass({ RedisConnectionFactory.class, RedisTemplate.class })
public class RedisConfig {
	@Autowired
	RedisProperties redisProperties;
	/**
	 * 
	 * @author hy
	 * @createTime 2021-05-01 08:40:59
	 * @description 基本的redisPoolConfig
	 * @return
	 *
	 */
	private JedisPoolConfig jedisPoolConfig() {
		JedisPoolConfig config = new JedisPoolConfig();
		config.setMaxIdle(redisProperties.getMaxIdle());
		config.setMaxTotal(redisProperties.getMaxTotal());
		config.setMaxWaitMillis(redisProperties.getMaxWaitMillis());
		config.setTestOnBorrow(redisProperties.getTestOnBorrow());
		return config;
	}
	/**
	 * @description 创建redis连接工厂
	 */
	@SuppressWarnings("deprecation")
	private JedisConnectionFactory jedisConnectionFactory() {
		JedisConnectionFactory factory = new JedisConnectionFactory(
				new JedisShardInfo(redisProperties.getHost(), redisProperties.getPort()));
		factory.setPassword(redisProperties.getPassword());
		factory.setTimeout(redisProperties.getTimeout());
		factory.setPoolConfig(jedisPoolConfig());
		factory.setUsePool(redisProperties.getUsePool());
		factory.setDatabase(redisProperties.getDatabase());
		return factory;
	}
	/**
	 * @description 创建RedisTemplate 的操作类
	 */
	@Bean
	public StringRedisTemplate getRedisTemplate() {
		StringRedisTemplate redisTemplate = new StringRedisTemplate();
		redisTemplate.setConnectionFactory(jedisConnectionFactory());
		redisTemplate.setEnableTransactionSupport(true);
		return redisTemplate;
	}
	@Bean
	public RedisMessageListenerContainer redisMessageListenerContainer() throws Exception {
		RedisMessageListenerContainer container = new RedisMessageListenerContainer();
		container.setConnectionFactory(jedisConnectionFactory());		
		return container;
	}
	// 创建基本的key监听器
	/*  */
	@Bean
	public RedisKeyChangeListener redisKeyChangeListener() throws Exception {
		RedisKeyChangeListener listener = new RedisKeyChangeListener(redisMessageListenerContainer(),"");
		return listener;
	}
}

/**
 * 
 * @author hy
 * @createTime 2021-05-01 08:38:26
 * @description 基本的redis的配置类
 *
 */
@ConfigurationProperties(prefix = "redis")
public class RedisProperties {
	private String host;
	private Integer port;
	private Integer database;
	private Integer timeout;
	private String password;
	private Boolean usePool;
	private Integer maxTotal;
	private Integer maxIdle;
	private Long maxWaitMillis;
	private Boolean testOnBorrow;
	private Boolean testWhileIdle;
	private Integer timeBetweenEvictionRunsMillis;
	private Integer numTestsPerEvictionRun;
	// 省略get\set方法
}

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-tomcat</artifactId>
    <scope>provided</scope>
</dependency>
<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>jstl</artifactId>
    <version>1.2</version>
    <scope>compile</scope>
</dependency>
<dependency>
    <groupId>org.apache.tomcat.embed</groupId>
    <artifactId>tomcat-embed-jasper</artifactId>
    <scope>compile</scope>
</dependency>
<dependency>
    <groupId>org.eclipse.jdt.core.compiler</groupId>
    <artifactId>ecj</artifactId>
    <version>4.6.1</version>
</dependency>

@WebListener
public class MyServletRequestListener implements ServletRequestListener {
    @Override
    public void requestDestroyed(ServletRequestEvent sre) {
        System.out.println("Request监听器，销毁");
    }
    @Override
    public void requestInitialized(ServletRequestEvent sre) {
        System.out.println("Request监听器，初始化");
    }
}

@RestController
public class DemoController {
    @RequestMapping("/fun")
    public void fun(){
        System.out.println("fun");
    }
}

@ServletComponentScan