@ConditionalOnProperty注解控制配置文件是否生效

最新推荐文章于 2025-07-31 15:01:26 发布

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该博客介绍了如何使用@Configuration和@ConditionalOnProperty注解来控制配置生效，基于应用属性动态加载配置。同时展示了如何配置Redis作为缓存管理器，包括RedisTemplate的配置和缓存序列化策略，以及启用缓存@EnableCaching的条件。

这个注解能够控制某个configuration是否生效。具体操作是通过其两个属性name以及havingValue来实现的，其中name用来从application.properties中读取某个属性值，如果该值为空，则返回false;如果值不为空，则将该值与havingValue指定的值进行比较，如果一样则返回true;否则返回false。如果返回值为false，则该configuration不生效；为true则生效。

@Configuration
//如果synchronize在配置文件中并且值为true
@ConditionalOnProperty(name = "synchronize", havingValue = "true")
public class SecondDatasourceConfig {

    @Bean(name = "SecondDataSource")
    @Qualifier("SecondDataSource")
    @ConfigurationProperties(prefix = "spring.second.datasource")
    public DataSource jwcDataSource() {
        return DataSourceBuilder.create().build();
    }
}

@EnableCaching  //启用缓存注解
@Configuration
@ConditionalOnProperty(name = "current.cache.enable", havingValue = "true")
public class RedisConfig extends CachingConfigurerSupport {

    /**
     * 注入生成key的策略(作用于注解注解缓存)
     */
    @Bean(name = "customKeyGenerator")
    public KeyGenerator keyGenerator() {
        return new RedisCacheKeyGenerator();
    }

    @Primary
    @Bean
    public CacheManager cacheManager(RedisConnectionFactory factory) {
        // 对象的序列化
        RedisSerializationContext.SerializationPair<Object> valueSerializationPair
                = RedisSerializationContext.SerializationPair.fromSerializer(jackson2JsonRedisSerializer());
        // 全局redis缓存过期时间。默认1天
        RedisCacheConfiguration redisCacheConfiguration = RedisCacheConfiguration.defaultCacheConfig()
                .entryTtl(Duration.ofDays(1))
//                .serializeKeysWith()
                .serializeValuesWith(valueSerializationPair);

        return new RedisCacheManager(RedisCacheWriter.nonLockingRedisCacheWriter(factory), redisCacheConfiguration);
    }

    /**
     * RedisTemplate配置
     * @param factory redis链接工厂
     * @return RedisTemplate
     */
    @Bean(name = "redisTemplate")
    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {
        RedisTemplate<String, Object> template = new RedisTemplate<>();
        RedisSerializer<String> redisSerializer = new StringRedisSerializer();

        // 设置序列化，key采用redisSerializer，value采用jackson2JsonRedisSerializer
        template.setConnectionFactory(factory);
        template.setKeySerializer(redisSerializer);
        template.setValueSerializer(jackson2JsonRedisSerializer());
        template.setHashKeySerializer(redisSerializer);
        template.setHashValueSerializer(jackson2JsonRedisSerializer());
        template.afterPropertiesSet();
        return template;
    }


    private Jackson2JsonRedisSerializer<Object> jackson2JsonRedisSerializer() {
        Jackson2JsonRedisSerializer<Object> jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer<>(Object.class);
        jackson2JsonRedisSerializer.setObjectMapper(objectMapper());
        return jackson2JsonRedisSerializer;
    }

    private ObjectMapper objectMapper() {
        ObjectMapper objectMapper = new ObjectMapper();
        objectMapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        objectMapper.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);

        // 解决jackson2无法反序列化LocalDateTime的问题
        objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
        objectMapper.registerModule(new JavaTimeModule());
        return objectMapper;
    }


}