Spring 未找到属性的 setter

Question

我正在尝试使用 Spring Boot 在 Kotlin 中进行配置data class。我有以下课程：

@Configuration
@ConfigurationProperties(prefix = "spring.braintree")
data class BraintreeConfigProperties(
    val merchantId: String = "",
    val publicKey: String = "",
    val privateKey: String = "",
    val environment: Environment = Environment.SANDBOX
)

以及以下属性：

spring.braintree.merchantId=${BRAINTREE_MERCHANT_ID}
spring.braintree.publicKey=${BRAINTREE_PUBLIC_KEY}
spring.braintree.privateKey=${BRAINTREE_PRIVATE_KEY}

当我运行该应用程序时，出现以下异常：

APPLICATION FAILED TO START
***************************

Description:

Failed to bind properties under 'spring.braintree' to com.x.ps.config.BraintreeConfigProperties$$EnhancerBySpringCGLIB$$311e0531:

    Property: spring.braintree.merchant-id
    Value: ${BRAINTREE_MERCHANT_ID}
    Origin: class path resource [application.properties] - 5:29
    Reason: java.lang.IllegalStateException: No setter found for property: merchant-id

Action:

Update your application's configuration

不过，我也有一个和班级一模一样的班级BraintreeConfigProperties。这个类（DatabaseConfigProperties）确实有效。它们是完全相同的。

我尝试过的：

1. 检查属性名称是否与配置名称实际匹配。
2. 分别尝试了所有三个配置属性。
3. 将值为 1234 的非环境变量附加到merchantId 属性，这会导致以下异常：

APPLICATION FAILED TO START
***************************

Description:

Failed to bind properties under 'spring.braintree' to com.x.ps.config.BraintreeConfigProperties$$EnhancerBySpringCGLIB$$62509e61:

    Property: spring.braintree.merchant-id
    Value: 1234
    Origin: class path resource [application.properties] - 5:29
    Reason: java.lang.IllegalStateException: No setter found for property: merchant-id

Action:

Update your application's configuration

Answer 1

这里的问题是val最终的并且var可以改变。所以你应该将你的属性更改为var.

更多信息：https://medium.com/mindorks/kotlin-series-val-vs-var-difference-android-kotlin-ecad780daeb7