Spring Boot 自動配置 : RedisAutoConfiguration

概述

Spring Boot關於Spring Data Redis的自動配置類。該自動配置類檢測到包spring-data-redis被使用時才應用。並且導入了另外兩個配置類LettuceConnectionConfiguration,JedisConnectionConfiguration,這兩個配置類是用於配置底層Redis連接組件RedisConnectionFactory,一種基於Lettuce Redis客戶端實現，一種基於Jedis Redis客戶端實現，不會同時生效。因爲包spring-boot-starter-data-redis自身依賴lettuce,所以缺省情況下，LettuceConnectionConfiguration會生效,JedisConnectionConfiguration不生效。

RedisAutoConfiguration自身主要的作用是確保以下bean存在於容器中 :

• RedisTemplate redisTemplate – 基於容器中的redisConnectionFactory bean
• StringRedisTemplate stringRedisTemplate – 基於容器中的redisConnectionFactory bean

redisConnectionFactory bean由LettuceConnectionConfiguration,JedisConnectionConfiguration或者其他方式定義。

源代碼

源代碼版本 : spring-boot-autoconfigure-2.1.3.RELEASE

package org.springframework.boot.autoconfigure.data.redis;

// 省略 import 行

/**
 * EnableAutoConfiguration Auto-configuration for Spring Data's Redis support.
 *
 */
@Configuration
@ConditionalOnClass(RedisOperations.class)
@EnableConfigurationProperties(RedisProperties.class)
@Import({ LettuceConnectionConfiguration.class, JedisConnectionConfiguration.class })
public class RedisAutoConfiguration {

    // 定義 bean RedisTemplate redisTemplate
	@Bean
    // 僅在該 bean 不存在的情況下才定義
	@ConditionalOnMissingBean(name = "redisTemplate")
	public RedisTemplate<Object, Object> redisTemplate(
			RedisConnectionFactory redisConnectionFactory) throws UnknownHostException {
		RedisTemplate<Object, Object> template = new RedisTemplate<>();
		template.setConnectionFactory(redisConnectionFactory);
		return template;
	}

    // 定義 bean StringRedisTemplate  stringRedisTemplate
	@Bean
      // 僅在該 bean 不存在的情況下才定義
	@ConditionalOnMissingBean
	public StringRedisTemplate stringRedisTemplate(
			RedisConnectionFactory redisConnectionFactory) throws UnknownHostException {
		StringRedisTemplate template = new StringRedisTemplate();
		template.setConnectionFactory(redisConnectionFactory);
		return template;
	}

}