当前位置：首页 > news >正文

@Autowired 和 @Resource思考（注入redisTemplate时发现一些奇怪的现象）

news 2025/6/23 17:45:48

1. 前置知识

@Configuration
public class RedisConfig {@Beanpublic RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {RedisTemplate<String, Object> template = new RedisTemplate<>();template.setConnectionFactory(factory);// 配置序列化器等template.afterPropertiesSet();return template;}
}

Bean 的名称
名称：redisTemplate（由于没有指定bean的名称，默认使用方法名）
类型：RedisTemplate<String, Object>

@Configuration
public class RedisConfig {@Bean(name = "systemRedisTemplate")public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {RedisTemplate<String, Object> template = new RedisTemplate<>();template.setConnectionFactory(factory);// 配置序列化器等template.afterPropertiesSet();return template;}
}

Bean 的名称
名称：systemRedisTemplate
类型：RedisTemplate<String, Object>

@Autowired

Spring 框架提供的注解，主要用于按类型（by type）进行依赖注入。Spring 容器会根据类型查找匹配的 Bean 并进行注入。如果存在多个匹配的 Bean，Spring 会抛出 NoUniqueBeanDefinitionException 异常。（注意：他不会主动按照名称去查找，除非使用@Qualifier）

@Resource

Java EE 标准注解，主要用于按名称（by name）进行依赖注入。如果找不到名称匹配的 Bean，则按类型注入。

2. 案例分析

目前的代码

@Configuration
public class RedisConfig {@Bean(name = "systemRedisTemplate")@SuppressWarnings("all")public RedisTemplate<String, Object> redisTemplate1(RedisConnectionFactory factory) {RedisTemplate<String, Object> template = new RedisTemplate<String, Object>();template.setConnectionFactory(factory);Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);ObjectMapper om = new ObjectMapper();om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);jackson2JsonRedisSerializer.setObjectMapper(om);StringRedisSerializer stringRedisSerializer = new StringRedisSerializer();// key采用String的序列化方式template.setKeySerializer(stringRedisSerializer);// hash的key也采用String的序列化方式template.setHashKeySerializer(stringRedisSerializer);// value序列化方式采用jacksontemplate.setValueSerializer(jackson2JsonRedisSerializer);// hash的value序列化方式采用jacksontemplate.setHashValueSerializer(jackson2JsonRedisSerializer);template.afterPropertiesSet();return template;}@Bean(name = "customRedisTemplate")@SuppressWarnings("all")public RedisTemplate<String, Object> redisTemplate2(RedisConnectionFactory factory) {RedisTemplate<String, Object> template = new RedisTemplate<String, Object>();template.setConnectionFactory(factory);Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);ObjectMapper om = new ObjectMapper();om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);jackson2JsonRedisSerializer.setObjectMapper(om);StringRedisSerializer stringRedisSerializer = new StringRedisSerializer();// key采用String的序列化方式template.setKeySerializer(stringRedisSerializer);// hash的key也采用String的序列化方式template.setHashKeySerializer(stringRedisSerializer);// value序列化方式采用jacksontemplate.setValueSerializer(jackson2JsonRedisSerializer);// hash的value序列化方式采用jacksontemplate.setHashValueSerializer(jackson2JsonRedisSerializer);template.afterPropertiesSet();return template;}
}

@Autowired
private RedisTemplate<String ,Object> redisTemplate;

先根据类型（RedisTemplate<String ,Object>）查找bean发现找不到，~~然后根据名字（redisTemplate）查bean~~（@Autowired不会自动使用名称注入，除非使用@Qualifier）报错：

NoUniqueBeanDefinitionException: No qualifying bean of type 'org.springframework.data.redis.core.RedisTemplate<java.lang.String, java.lang.Object>' available: expected single matching bean but found 2: systemRedisTemplate,customRedisTemplate

解决办法