想在一个JAVA Class 向同一个Redis实例的不同 dbindex 写入数据，非常类似于StackOverflowe上的[How can select dbIndex when I use RedisTemplate in Spring-Data-Redis?。在这篇文章中描述了如何使用Spring boot访问Redis，在创建JedisConnectionFactory的时候指定dbindex：

JedisConnectionFactory factory = new JedisConnectionFactory(); ... factory.setDatabase(databaseId);//set dbindex

因此，大概思路是配置2个RedisTemplate，其中一个RedisTemplate负责访问dbindex=1的数据库；另一个RedisTemplate负责访问dbindex=3的数据库。

根据这篇文章，因此通过 @Bean(name=) 生成多个RedisTemplate。但是由于生成RedisTemplate需要传入JedisConnectionFactory实例，而我们是在JedisConnectionFactory中指定了访问Redis的哪个数据库(dbindex)。因此，就在创建JedisConnectionFactory实例的时候，使用 @Scope(scopeName = "prototype") 注解，这样的话Jedis连接工厂就不再是单例模式了。因此，就有两个JedisConnectionFactory实例，每个实例通过jedisConnectionFactory.setDatabase()设置不同的dbindex。这种方式可能非常愚蠢，会引起严重的性能问题。

下面，来看看具体是怎么配置的：

@Scope(scopeName = "prototype") public JedisConnectionFactory jedisConnectionFactory() { JedisPoolConfig config = getRedisConfig(); JedisConnectionFactory factory = new JedisConnectionFactory(config); factory.setUsePool(true); factory.setHostName(host); factory.setPort(port); return factory; }

每调用一次jedisConnectionFactory() 返回一个新的JedisConnectionFactory实例。

然后定义2个RedisTemplate Bean，jedisConnectionFactory.setDatabase() 方法分别设置不同的dbindex

import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Value; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.Scope; import org.springframework.data.redis.connection.jedis.JedisConnectionFactory; import org.springframework.data.redis.core.RedisTemplate; import org.springframework.data.redis.serializer.StringRedisSerializer; import redis.clients.jedis.JedisPoolConfig; import java.util.Map; /** * Created by Administrator on 2018/4/9. */ @Configuration public class LoginMacRedisConfig { private static final Logger logger = LoggerFactory.getLogger(LoginMacRedisConfig.class); @Value("1") private int logmacDatabaseId; @Value("3") private int mobmaskDatabaseId; @Bean public JedisPoolConfig getRedisConfig() { JedisPoolConfig config = new JedisPoolConfig(); config.setMaxIdle(8); config.setMinIdle(0); return config; } @Scope(scopeName = "prototype") public JedisConnectionFactory jedisConnectionFactory() { JedisPoolConfig config = getRedisConfig(); JedisConnectionFactory factory = new JedisConnectionFactory(config); factory.setUsePool(true); factory.setHostName(host); factory.setPort(port); return factory; } @Bean(name = "login_mac") public RedisTemplate> logmacRedisTemplate() { final RedisTemplate> template = new RedisTemplate<>(); JedisConnectionFactory jedisConnectionFactory = jedisConnectionFactory(); jedisConnectionFactory.setDatabase(logmacDatabaseId); template.setConnectionFactory(jedisConnectionFactory); logger.info("host:{}, port:{}, database:{}", jedisConnectionFactory.getHostName(),jedisConnectionFactory.getPort(), jedisConnectionFactory.getDatabase()); StringRedisSerializer stringRedisSerializer = new StringRedisSerializer(); template.setKeySerializer(stringRedisSerializer); template.setHashKeySerializer(stringRedisSerializer); template.setHashValueSerializer(stringRedisSerializer); return template; } @Bean(name = "mobile_mask") public RedisTemplate> mobileMaskRedisTemplate() { final RedisTemplate> template = new RedisTemplate<>(); JedisConnectionFactory jedisConnectionFactory = jedisConnectionFactory(); jedisConnectionFactory.setDatabase(mobmaskDatabaseId); template.setConnectionFactory(jedisConnectionFactory); logger.info("host:{}, port:{}, database:{}", jedisConnectionFactory.getHostName(),jedisConnectionFactory.getPort(), jedisConnectionFactory.getDatabase()); StringRedisSerializer stringRedisSerializer = new StringRedisSerializer(); template.setKeySerializer(stringRedisSerializer); template.setHashKeySerializer(stringRedisSerializer); template.setHashValueSerializer(stringRedisSerializer); return template; } }

最后，再写一个Service类，就可以同时注入这两个RedisTemplate，操作同一个Redis服务器上的不同的dbindex了。

import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.data.redis.core.HashOperations; import org.springframework.data.redis.core.RedisTemplate; import org.springframework.stereotype.Service; import java.util.HashMap; import java.util.Map; /** * Created by Administrator on 2018/4/10. */ @Service public class RedisTestService { @Autowired @Qualifier("login_mac") private RedisTemplate> template1; @Autowired @Qualifier("mobile_mask") private RedisTemplate> template2; public void write2Redis() { HashOperations hashOperations = template1.opsForHash(); Map values = new HashMap<>(); values.put("dbindex", "1"); hashOperations.putAll("123", values); template2.opsForHash().put("123", "dbindex", "3"); } }

Application.java 启动类

@SpringBootApplication public class Application implements CommandLineRunner{ @Autowired private RedisTestService redisTestService; public static void main(String[] args) { SpringApplication.run(Application.class, args); } @Override public void run(String... strings) throws Exception { redisTestService.write2Redis(); } }

在redisTestService对象中：有两个RedisTemplate实例：

两个RedisTemplate实例分别封装了两个JedisConnectionFactory：

调试结果下： 2018-04-10 20:18:34.754 INFO 13512 --- [ main] c.y.t.c.redis.LoginMacRedisConfig : host:192.168.107.253, port:6379, database:1

2018-04-10 20:19:06.972 INFO 13512 --- [ main] c.y.t.c.redis.LoginMacRedisConfig : host:192.168.107.253, port:6379, database:3

最终查看写入Redis结果，可以看出：dbindex 1 和 dbindex 3 都分别成功写入了数据。

redis 192.168.107.253:6379> SELECT 1 OK redis 192.168.107.253:6379[1]> KEYS * 1) "123" redis 192.168.107.253:6379[1]> HGET 123 dbindex "1" redis 192.168.107.253:6379[1]> SELECT 3 OK redis 192.168.107.253:6379[3]> KEYS * 1) "123" redis 192.168.107.253:6379[3]> HGET 123 dbindex "3"

其实要在同一个应用中访问不同的dbindex，一种方式是使用JedisPool，JedisPool创建Jedis，然后调用select方法选择dbindex。具体实现可参考这篇文章。但这样的话，就不能使用RedisTemplate的各种方便的接口读写Redis了。

@Bean public JedisPool redisPoolFactory() { JedisPool jedisPool = new JedisPool(jedisPoolConfig(), host, port); Jedis jedis = jedisPool.getResource(); jedis.select(3); return jedisPool; }

其实是可以像说的：通过RedisConnectionCommand的 select 方法来选择dbindex的，但是还是同样的问题，用不了RedisTemplate。

RedisConnection redisConnection = redisTemplate.getConnectionFactory().getConnection(); DefaultStringRedisConnection stringRedisConnection = new DefaultStringRedisConnection(redisConnection); stringRedisConnection.select(2); stringRedisConnection.set("test", "test");

另外这里也有一篇Spring Boot Redis多实例配置，也可以参考一下。Spring Boot 兼Redis新手，只能这样了。