springBoot集成Redis遇到的坑(择库)源码分析为什么择库失败

1.配置实现SpringBoot集成Redis(只需两步)

1.最简单的配置就是在application.propertity中配置

#cache指定缓存类型
spring.cache.type=REDIS

#data-redis
spring.redis.database=15
spring.redis.password=
spring.redis.host=192.168.**.**
spring.redis.port=6379
spring.redis.timeout=2000
spring.redis.jedis.pool.max-active=8 
spring.redis.jedis.pool.max-idle=8 
spring.redis.jedis.pool.max-wait=-1 
spring.redis.jedis.pool.min-idle=0 

2.启动类开启缓存

@SpringBootApplication
@EnableCaching
public class EvaluationApplication {}

2.你有没有想过为啥SpringBoot集成Redis的配置那么简单？

原因：

1.SpringBoot之所以好用就是因为他替我们做了很多以前我们需要手动在Spring中做的工作。

2.SpringBoot中默认是带了一个jar包：org.springframework.boot.autoconfigure这个包包含了大部分SpringBoot默认实现的功能，感兴趣的童鞋可以自己看下

3.我们可以在这个package org.springframework.boot.autoconfigure.data.redis;下看到SB为我们默认实现的代码：

4.我们可以看到JedisConnectionConfiguration类

@Configuration //启动加载
@ConditionalOnClass({ GenericObjectPool.class, JedisConnection.class, Jedis.class })
class JedisConnectionConfiguration extends RedisConnectionConfiguration {

    private final RedisProperties properties;

    private final List<JedisClientConfigurationBuilderCustomizer> builderCustomizers;

    JedisConnectionConfiguration(RedisProperties properties,
            ObjectProvider<RedisSentinelConfiguration> sentinelConfiguration,
            ObjectProvider<RedisClusterConfiguration> clusterConfiguration,
            ObjectProvider<List<JedisClientConfigurationBuilderCustomizer>> builderCustomizers) {
        super(properties, sentinelConfiguration, clusterConfiguration);
        this.properties = properties;
        this.builderCustomizers = builderCustomizers
                .getIfAvailable(Collections::emptyList);
    }

    @Bean  //启动加载JedisConnectionFactory放入spring的容器中
    @ConditionalOnMissingBean(RedisConnectionFactory.class)
    public JedisConnectionFactory redisConnectionFactory() throws UnknownHostException {
        return createJedisConnectionFactory();
    }

    private JedisConnectionFactory createJedisConnectionFactory() {
        JedisClientConfiguration clientConfiguration = getJedisClientConfiguration();
        if (getSentinelConfig() != null) {//如果配置文件中配置了多个节点，则以多节点方式加载   此方式上面配置部分无效，详情看源码
            return new JedisConnectionFactory(getSentinelConfig(), clientConfiguration);
        }
        if (getClusterConfiguration() != null) {//如果配置了集群则以集群方式加载   此方式上面配置部分无效，详情看源码
            return new JedisConnectionFactory(getClusterConfiguration(),
                    clientConfiguration);
        }
        return new JedisConnectionFactory(getStandaloneConfig(), clientConfiguration);//以单节点的方式加载redis配置，上面配置生效
    }

5.附上最后一中方式加载的源码

protected final RedisStandaloneConfiguration getStandaloneConfig() {
        RedisStandaloneConfiguration config = new RedisStandaloneConfiguration();
        if (StringUtils.hasText(this.properties.getUrl())) {
            ConnectionInfo connectionInfo = parseUrl(this.properties.getUrl());
            config.setHostName(connectionInfo.getHostName());
            config.setPort(connectionInfo.getPort());
            config.setPassword(RedisPassword.of(connectionInfo.getPassword()));
        }
        else {
            config.setHostName(this.properties.getHost()); //这个propertity就是加载的上面的配置，源码可以看到上面图片中有个RedisPropertity类，配置文件中的配置就是根据这个类配置的
            config.setPort(this.properties.getPort());
            config.setPassword(RedisPassword.of(this.properties.getPassword()));
        }
        config.setDatabase(this.properties.getDatabase());
        return config;
    }

3.那么问题来了，为什么我一直择库失败呢？

spring.redis.database=15  //为什么的我这个配置一直不生效呢？  我想你心里应该有答案了