对于应用程序配置定义的application.properties，Spring是否遵循任何命名约定？

我面对的是Spring配置的奇怪问题，因为application.properties以特定方式命名配置时，环境变量不会覆盖其中定义的配置。如外部化配置 OS中所述，环境变量优先于，application.properties但是在将配置定义为时不会发生这种情况，myExternal_url但是在将配置定义为时才起作用my_external_url（在下面的示例代码中，我们需要将配置更改为my_external_urlin ApplicationProperties.java和application.properties）

示例代码-

@SpringBootApplication
public class ConfigApplication implements ApplicationRunner {

  @Autowired private ApplicationProperties applicationProperties;

  public static void main(String[] args) {
    SpringApplication.run(ConfigApplication.class, args);
  }

  @Override
  public void run(ApplicationArguments arg0) {
    System.out.println("External URL = " + applicationProperties.getMyExternalUrl());
  }
}

应用Bean配置-

@Configuration
public class AppConfig {

  @Bean
  @ConfigurationProperties(prefix = "")
  public ApplicationProperties applicationProperties() {
    return new ApplicationProperties();
  }
}

ApplicationProperties 类-

public class ApplicationProperties {

  @Value("${myExternal_url}")
  private String myExternalUrl;

  public String getMyExternalUrl() {
    return this.myExternalUrl;
  }

  public void setMyExternalUrl(String myExternalUrl) {
    this.myExternalUrl = myExternalUrl;
  }
}

application.properties：

myExternal_url=external_url_env_application_properties

这可能是什么原因？

编辑-添加gradle Gradle配置

plugins {
    id 'org.springframework.boot' version '2.4.0-M1'
    id 'io.spring.dependency-management' version '1.0.9.RELEASE'
    id 'java'
}

group = 'com.example'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = '1.8'

repositories {
    mavenCentral()
    maven { url 'https://repo.spring.io/milestone' }
}

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-web'
    testImplementation 'org.springframework.boot:spring-boot-starter-test'
    compileOnly 'org.projectlombok:lombok:1.18.6'
    annotationProcessor 'org.projectlombok:lombok:1.18.6'
}

test {
    useJUnitPlatform()
}

编辑2

跟踪日志显示myExternal_url已从Environment变量正确解析。然后，Spring尝试applicationProperties通过调用解析自动装配的依赖项' ' AutowiredAnnotationBeanPostProcessor，然后使用application.properties值覆盖该值（屏幕截图）。

o.s.c.e.PropertySourcesPropertyResolver  : Found key 'myExternal_url' in PropertySource 'systemEnvironment' with value of type String
o.s.c.e.PropertySourcesPropertyResolver  : Found key 'myExternal_url' in PropertySource 'environmentProperties' with value of type String