项目使用指定的数据库

需求1：
甲方有很多系统用redis，我们这个系统需要指定用到4数据库

在配置文件中设置数据库

spring:
  redis:
    host: xx
    port: xx
    password: xxx
    database: 1

redis配置类

@Configuration
@EnableCaching
/**
 * redis配置
 */
public class RedisConfig extends CachingConfigurerSupport {
     @Value("${spring.redis.host}")
     private String host;

     @Value("${spring.redis.port}")
     private int port;

     @Value("${spring.redis.password}")
     private String password;

     @Value("${spring.redis.database}")
     private Integer database;

	/**
     连接配置
     */
     @Bean
     RedisStandaloneConfiguration redisStandaloneConfiguration() {
     RedisStandaloneConfiguration redisStandaloneConfiguration = new RedisStandaloneConfiguration();
     redisStandaloneConfiguration.setDatabase(database);
     redisStandaloneConfiguration.setHostName(host);
     redisStandaloneConfiguration.setPort(port);
     redisStandaloneConfiguration.setPassword(RedisPassword.of(password));
     return redisStandaloneConfiguration;
     }
     
     /**
     Lettuce 配置
     */
     @Bean
     @Primary
     RedisConnectionFactory redisConnectionFactory() {
     return new LettuceConnectionFactory(redisStandaloneConfiguration(),
     LettuceClientConfiguration.builder()
     // 超时时间
     .commandTimeout(Duration.ofMinutes(30)).build());
     }
    /**
     * 模板
     * @param connectionFactory 连接工厂
     * @return {@link RedisTemplate<Object, Object>}
     */
    @Bean
    @SuppressWarnings(value = { "unchecked", "rawtypes" })
    public RedisTemplate<Object, Object> redisTemplate()
    {
        RedisTemplate<Object, Object> template = new RedisTemplate<>();
        // 这里不再使用默认的RedisConnectionFactory配置，走我们自定义的
        template.setConnectionFactory(connectionFactory());

        FastJsonRedisSerializer serializer = new FastJsonRedisSerializer(Object.class);

        ObjectMapper mapper = new ObjectMapper();
        mapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        mapper.activateDefaultTyping(LaissezFaireSubTypeValidator.instance, ObjectMapper.DefaultTyping.NON_FINAL, JsonTypeInfo.As.PROPERTY);
        serializer.setObjectMapper(mapper);

        // 使用StringRedisSerializer来序列化和反序列化redis的key值
        template.setKeySerializer(new StringRedisSerializer());
        template.setValueSerializer(serializer);
        // Hash的key也采用StringRedisSerializer的序列化方式
        template.setHashKeySerializer(new StringRedisSerializer());
        template.setHashValueSerializer(serializer);

        template.afterPropertiesSet();
        return template;
    }
}

...

项目中动态切换数据库

需求2：实现在项目中动态的切换

@Component
public class RedisService {
    
    @Resource
    public RedisTemplate redisTemplate;

    @Value("${spring.redis.database}")
    private Integer database;

    /**
     * 设置数据库索引
     *
     * @param dbIndex 数据库索引
     */
    private void setDbIndex(Integer dbIndex) {
        if (dbIndex == null || dbIndex > 15 || dbIndex < 0) {
            dbIndex = database;
        }
        LettuceConnectionFactory redisConnectionFactory = (LettuceConnectionFactory) redisTemplate
                .getConnectionFactory();
        if (redisConnectionFactory == null) {
            return;
        }
        redisConnectionFactory.setDatabase(dbIndex);
        redisTemplate.setConnectionFactory(redisConnectionFactory);
        // 属性设置后
        redisConnectionFactory.afterPropertiesSet();
        // 重置连接
        redisConnectionFactory.resetConnection();
    }

    /**
     * 缓存基本的对象，Integer、String、实体类等
     *
     * @param key 缓存的键值
     * @param value 缓存的值
     */
    public <T> void setCacheObject(final String key, final T value) {
        redisTemplate.opsForValue().set(key, value);
    }

    /**
     * 设置缓存对象
     * 缓存基本的对象，Integer、String、实体类等
     *
     * @param key   缓存的键值
     * @param value 缓存的值
     * @param index 指数
     */
    public <T> void setCacheObject(Integer index, final String key, final T value) {
        setDbIndex(index);
        redisTemplate.opsForValue().set(key, value);
    }

...

测试使用

redisService.setCacheObject("xxx", "567567567567567");

redisService.setCacheObject(8, "ces", "567567567567567");