Spring boot 使用多个RedisTemplate

问题描述

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<String, Map<String, String>> logmacRedisTemplate() {
	final RedisTemplate<String, Map<String, String>> 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<String, Map<String, String>> mobileMaskRedisTemplate() {
	final RedisTemplate<String, Map<String, String>> 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<String, Map<String, String>> template1;

    @Autowired
    @Qualifier("mobile_mask")
    private RedisTemplate<String, Map<String, String>> template2;

    public void write2Redis() {
	HashOperations<String, String, String> hashOperations = template1.opsForHash();
	Map<String, String> 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"

额外补充

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。

原文：http://www.cnblogs.com/hapjin/p/8783084.html