测试时将使用src / main / resources和src / test / resources目录中的哪个application.yml

Question

In a spring boot Maven project, there's a application.yml file in src/main/resources and src/test/resources respectively.

When running test cases, it seems that testing will only use the file in src/test/resources directory.It won't load two files and override the properties in src/main/resources/application.yml . And if there isn't the file in src/test/resources directory, it will use the file in src/main/resources directory.

How does spring boot to load the application.yml file in these two directories? What're the rules? or What does this action depend on?
Where can I look up more information about this online?

Example:

└───spring-boot-main-test-application-yaml
    ├───pom.xml
    └───src
        ├───main
        │   ├───java
        │   ├───resources
        │       ├───application.yml
        │   
        ├───test
            ├───java
            ├───resources
                └─── application.yml

src/main/resource/application.yml

name: Phil(main)
sample:
  name: Andy(main)

src/test/resource/application.yml

name: Phil(test)
sample:
  name: Andy(test)

case1: src/main/resource/application.yml exists
output: Hello Phil(main),Andy(main)

case2: src/main/resource/application.yml and src/test/resource/application.yml both exist
output: Hello Phil(test),Andy(test)

case3: src/main/resource/application.yml and src/test/resource/application.yml both exist and comment out name in src/test/resource/application.yml
output:
Error - java.lang.IllegalArgumentException: Could not resolve placeholder 'name' in value "${name}"

It seems that this test didn't read properties from src/main/resource/application.yml so it couldn't find out name property.

Answer 1

Spring detects those two directories and like you said it's figuring out which configs to use based on presence and priority. If you wanted spring to use a particular setting you should define spring profiles which can have specialized settings as well as extend default settings.

Answer 2

I am working with yml file and make sure that these property files are loaded when the app is build, it is preferred to have the following config in pom.xml

<build>

        <resources>
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.yml</include>
                    <include>**/*.jks</include>

                </includes>
            </resource>
        </resources>
        <testResources>
            <testResource>
                <directory>${project.basedir}/src/test/resources</directory>
            </testResource>
        </testResources>
 ....
</build>

Make sure to run the build (if required start from scratch like deleting the repository folder inside .m2 - This might not be needed at all) Now check the target/classes and that should contain the files of all the specified types