Spring Boot 2.7升级3.0.7后@ConfigurationProperties注入失败

问题原因 #

Spring Boot 3.0对@ConfigurationProperties类的实例化机制做了调整：这类类默认采用构造方法绑定配置属性，不再参与常规的Spring依赖注入流程。因此你无法直接在它的构造方法或字段中注入其他Spring管理的Bean（比如ConfigRepository），这就是升级后构造参数为null的根本原因。

可行调整方案 #

方案一：将Properties类注册为Bean并依赖注入 #

给ConnectorProperties添加@Component注解，将其纳入Spring Bean管理，再通过@Autowired注入ConfigRepository：

@Component
@ConfigurationProperties(ConnectorProperties.PREFIX)
public class ConnectorProperties {
    static final String PREFIX = "connector";

    @Autowired
    private ConfigRepository configRepository;

    // 移除原带参构造，保留无参构造
    public ConnectorProperties() {}

    private long gracefulShutdownPeriod = 60; // 替换@Value，用默认值实现配置绑定

    public List<String> getPartners() {
       return configRepository.getPartners();
    }
    
    public void setGracefulShutdownPeriod(long gracefulShutdownPeriod) {                       
        this.gracefulShutdownPeriod = gracefulShutdownPeriod;                                  
    }    
                                
    public long getGracefulShutdownPeriod() {   
        return gracefulShutdownPeriod;          
    }                                                                                                 
}

注：这里把@Value换成了字段默认值，更符合@ConfigurationProperties的配置绑定规范，配置项会自动读取connector.graceful-shutdown-period的值。

方案二：通过配置类手动构建Properties Bean（推荐） #

创建独立配置类，注入ConfigRepository后手动构建ConnectorProperties实例，明确分离配置绑定与依赖注入逻辑：

首先修改ConnectorProperties，添加ConfigRepository的setter方法：

@ConfigurationProperties(ConnectorProperties.PREFIX)
public class ConnectorProperties {
    static final String PREFIX = "connector";

    private ConfigRepository configRepository;

    private long gracefulShutdownPeriod = 60;

    public ConnectorProperties() {}

    public void setConfigRepository(ConfigRepository configRepository) {
        this.configRepository = configRepository;
    }
    
    public List<String> getPartners() {
       return configRepository.getPartners();
    }
    
    public void setGracefulShutdownPeriod(long gracefulShutdownPeriod) {                       
        this.gracefulShutdownPeriod = gracefulShutdownPeriod;                                  
    }    
                                
    public long getGracefulShutdownPeriod() {   
        return gracefulShutdownPeriod;          
    }                                                                                                 
}

然后创建配置类：

@Configuration
@EnableConfigurationProperties
public class ConnectorConfig {

    @Bean
    @ConfigurationProperties(ConnectorProperties.PREFIX)
    public ConnectorProperties connectorProperties(ConfigRepository configRepository) {
        ConnectorProperties properties = new ConnectorProperties();
        properties.setConfigRepository(configRepository);
        return properties;
    }
}

内容的提问来源于stack exchange，提问作者tgillain