Spring Bean初始化时@Value注入失效，如何正确加载配置？

你遇到的问题核心是@AllArgsConstructor与@Value的注入冲突：Spring会优先尝试构造注入，但你的构造函数依赖超时参数，此时配置还未完成加载，导致初始化失败。以下是几种可行的解决方式：

直接移除@AllArgsConstructor，让Spring通过字段注入加载配置，同时调整webClient的依赖方式，避免手动调用方法引发的初始化顺序问题：

@Configuration
@Slf4j
public class Config {

    @Value("${connectionTimeout}") 
    int connectionTimeout;
    @Value("${responseTimeout}") 
    int responseTimeout;

    @Bean
    public ClientHttpConnector getConnector() {
        HttpClient client = HttpClient.create()
                .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, connectionTimeout)
                .responseTimeout(Duration.ofMillis(responseTimeout));

        return new ReactorClientHttpConnector(client);
    }

    @Bean
    public WebClient webClient(ClientHttpConnector connector) {
        return WebClient.builder()
                .defaultHeader(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_FORM_URLENCODED_VALUE)
                .clientConnector(connector)
                .build();
    }
}

你之前尝试该方式无效，大概率是缺少关键配置步骤。完整流程如下：

1. 定义专门的配置绑定类（必须包含getter/setter）：

@ConfigurationProperties(prefix = "http")
public class HttpTimeoutProperties {
    private int connectionTimeout;
    private int responseTimeout;

    public int getConnectionTimeout() {
        return connectionTimeout;
    }

    public void setConnectionTimeout(int connectionTimeout) {
        this.connectionTimeout = connectionTimeout;
    }

    public int getResponseTimeout() {
        return responseTimeout;
    }

    public void setResponseTimeout(int responseTimeout) {
        this.responseTimeout = responseTimeout;
    }
}

2. 修改application.properties添加前缀（可选但更规范）：

http.connectionTimeout=30000
http.responseTimeout=30000

3. 在配置类中开启配置绑定并注入：

@Configuration
@Slf4j
@EnableConfigurationProperties(HttpTimeoutProperties.class)
public class Config {

    private final HttpTimeoutProperties timeoutProperties;

    public Config(HttpTimeoutProperties timeoutProperties) {
        this.timeoutProperties = timeoutProperties;
    }

    @Bean
    public ClientHttpConnector getConnector() {
        HttpClient client = HttpClient.create()
                .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, timeoutProperties.getConnectionTimeout())
                .responseTimeout(Duration.ofMillis(timeoutProperties.getResponseTimeout()));

        return new ReactorClientHttpConnector(client);
    }

    @Bean
    public WebClient webClient(ClientHttpConnector connector) {
        return WebClient.builder()
                .defaultHeader(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_FORM_URLENCODED_VALUE)
                .clientConnector(connector)
                .build();
    }
}

无需额外注解，在Bean初始化方法中直接注入Environment读取配置：

@Configuration
@Slf4j
public class Config {

    @Bean
    public ClientHttpConnector getConnector(Environment env) {
        int connectionTimeout = Integer.parseInt(env.getProperty("connectionTimeout"));
        int responseTimeout = Integer.parseInt(env.getProperty("responseTimeout"));

        HttpClient client = HttpClient.create()
                .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, connectionTimeout)
                .responseTimeout(Duration.ofMillis(responseTimeout));

        return new ReactorClientHttpConnector(client);
    }

    @Bean
    public WebClient webClient(ClientHttpConnector connector) {
        return WebClient.builder()
                .defaultHeader(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_FORM_URLENCODED_VALUE)
                .clientConnector(connector)
                .build();
    }
}

内容的提问来源于stack exchange，提问作者NotMyRealName32