java - 即使依赖 Bean 存在，创建 Bean 时出错

Question

我的配置类有一些依赖 Bean

public class WebConfig{
    @Bean
        @Qualifier("geojedis")
        public StringRedisTemplate geoJedisTemplate(
                @Qualifier("geographyJedisConnectionFactory") final JedisConnectionFactory connectionFactory) {

            // Create a RedisTemplate implementation which is basically of string
            // data structure.
            StringRedisTemplate redisTemplate = new StringRedisTemplate(connectionFactory);

            return redisTemplate;
        }

    @Bean
        @Qualifier("capacityStringRedisTemplate")
        public StringRedisTemplate capacityStringRedisTemplate(
                @Qualifier("capacityJedisConnectionFactory") final JedisConnectionFactory connectionFactory) {

            // Create a RedisTemplate implementation which is basically of string
            // data structure.
            StringRedisTemplate redisTemplate = new StringRedisTemplate(connectionFactory);

            return redisTemplate;
        }

    @Bean
        public JedisConnectionFactory geographyJedisConnectionFactory() {
            JedisConnectionFactory connectionFactory = new JedisConnectionFactory();
            return connectionFactory;
        }

    @Bean
        public JedisConnectionFactory capacityJedisConnectionFactory() {
            JedisConnectionFactory connectionFactory = new JedisConnectionFactory();
            return connectionFactory;
        }
    }

但我收到以下错误。当我检查配置时，一切都很好，我还定义了 Qualifier 来映射正确的依赖项。非常感谢任何帮助。

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'redisTemplate' defined in class path resource [org/springframework/boot/autoconfigure/redis/RedisAutoConfiguration$RedisConfiguration.class]: Unsatisfied dependency expressed through constructor argument with index 0 of type [org.springframework.data.redis.connection.RedisConnectionFactory]: : No qualifying bean of type [org.springframework.data.redis.connection.RedisConnectionFactory] is defined: expected single matching bean but found 2: geographyJedisConnectionFactory,capacityJedisConnectionFactory; nested exception is org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [org.springframework.data.redis.connection.RedisConnectionFactory] is defined: expected single matching bean but found 2: geographyJedisConnectionFactory,capacityJedisConnectionFactory

Answer 1

如果 Spring 上下文中没有默认的“redisTemplate”，RedisAutoConfiguration 中会创建一个 bean。

@Bean
@ConditionalOnMissingBean(name = "redisTemplate")
public RedisTemplate<Object, Object> redisTemplate(
        RedisConnectionFactory redisConnectionFactory) throws UnknownHostException {
    RedisTemplate<Object, Object> template = new RedisTemplate<>();
    template.setConnectionFactory(redisConnectionFactory);
    return template;
}

这需要一个 RedisConnectionFactory，但找到了两个。

作为变通方法，您可以创建一个名为“redisTemplate”的虚拟 RedisTemplate 而不是使用它。

因为它通过 bean 名称检查，所以只要没有尝试@Autowire 它，下面的内容就足够了:

@Bean
public Object redisTemplate() {
    return new Object();
}