查閱官方文件：https://docs.spring.io/spring-boot/docs/1.5.17.RELEASE/reference/htmlsingle/#boot-features-adding-active-profiles

Profiles
Spring Profiles provide a way to segregate parts of your application configuration and make it only available in certain environments. Any @Component or @Configuration can be marked with @Profile to limit when it is loaded:

@Configuration
@Profile("production")
public class ProductionConfiguration {

    // ...

}
In the normal Spring way, you can use a spring.profiles.active Environment property to specify which profiles are active. You can specify the property in any of the usual ways, for example you could include it in your application.properties:

spring.profiles.active=dev,hsqldb
or specify on the command line using the switch --spring.profiles.active=dev,hsqldb.

25.1 Adding active profiles
The spring.profiles.active property follows the same ordering rules as other properties, the highest PropertySource will win. This means that you can specify active profiles in application.properties then replace them using the command line switch.

Sometimes it is useful to have profile-specific properties that add to the active profiles rather than replace them. The spring.profiles.include property can be used to unconditionally add active profiles. The SpringApplication entry point also has a Java API for setting additional profiles (i.e. on top of those activated by the spring.profiles.active property): see the setAdditionalProfiles() method.

For example, when an application with following properties is run using the switch --spring.profiles.active=prod the proddb and prodmq profiles will also be activated:

---
my.property: fromyamlfile
---
spring.profiles: prod
spring.profiles.include:
  - proddb
  - prodmq
[Note]
Remember that the spring.profiles property can be defined in a YAML document to determine when this particular document is included in the configuration. See Section 72.7, “Change configuration depending on the environment” for more details.

25.2 Programmatically setting profiles
You can programmatically set active profiles by calling SpringApplication.setAdditionalProfiles(…​) before your application runs. It is also possible to activate profiles using Spring’s ConfigurableEnvironment interface.

25.3 Profile-specific configuration files
Profile-specific variants of both application.properties (or application.yml) and files referenced via @ConfigurationProperties are considered as files are loaded. See Section 24.4, “Profile-specific properties” for details.
 

我的問題，是多環境配置錯誤：

--spring.profiles.active=dev