Spring 引导类路径配置文件覆盖外部 application.properties

Question

I want to have Spring load an external configuration file if present and else use the once provided in src/main/resources.

Current setup:

src/main/resources/application.properties
src/main/resources/application-dev.properties
src/main/resources/application-prod.properties

/this/is/an/external/dir/application-dev.properties

Similar to https://stackoverflow.com/a/27776123/5126654 I added the following annotations:

@EnableFeignClients
@SpringBootApplication
@EnableEncryptableProperties
@PropertySources({ //
    @PropertySource("classpath:application.properties"), //
    @PropertySource(value = "file:${external.config}", ignoreResourceNotFound = true) //
})
public class Application extends SpringBootServletInitializer {

   // ....
}

And have the following entry in my application.properties:

external.config=/this/is/an/external/dir/application-dev.properties

I also can see that the external conifguration file is picked up. The problem I have is that every entry in the classpath properties file overwrites the external ones. Ie instead of taking entries from /this/is/an/external/dir/application-dev.properties entries from src/main/resources/application-dev.properties are taken.

How can I modify my code such that the external file overrides the entries of the classpath file?

Answer 1

Just change the order of importing. Something like:

<context:property-placeholder file-encoding="UTF-8"
                            location="${YOUR_CUSTOM_PATH}/global.properties ,
                                      ${YOUR_CUSTOM_PATH}/local.properties" ignore-unresolvable="true"/>

or

@PropertySource(value = {"classpath:global.properties" , "local.properties"},ignoreResourceNotFound = true)

In this case the local.properties overrides properties of global.properties

Answer 2

Since you only want the external config for development, you could as well consider setting external property source as a command line argument in the IDE run configuration for your project.

--spring.config.location=/this/is/an/external/dir/application-dev.properties

The property source specified in the above manner overrides the application.properties present in class path.

Answer 3

I want to have Spring load an external configuration file if present and else use the once provided in src/main/resources.

That's the default behavior of Spring Boot. So you just need to enable it correctly.

First of all, remove next annotations, they may disrupt/override the default mechanism:

@PropertySources({ //
    @PropertySource("classpath:application.properties"), //
    @PropertySource(value = "file:${external.config}", ignoreResourceNotFound = true) //
})

Then specify location of your file as a command line argument:

java -jar myapp.jar --spring.config.additional-location=/this/is/an/external/dir/

More information here:

• Spring Boot Features - Externalized Configuration
• Common Application properties - Core properties

Then either rename your config to application.properties or specify your dev profile (suffix in your file name) via another environmental variable:

-Dspring-boot.run.profiles=dev

Related question: Setting active profile and config location from command line in spring boot