How to get Intellij to recognize properties in application.yml

• Turn the annotation processing on
• Do not delegate IDE build/run actions to Gradle
• Rebuild your project in IDE: Build -> Rebuild Project

As far as I can tell, IntelliJ (at the time of this writing, 2018.1.2) wants the spring-configuration-metadata.json file to either be in a main source root (src/main/resources/META-INF/ or src/main/java/META-INF/) or in its default output directory for it to pick it up for autocompletion of properties in your source tree. To expand on phospodka's comment, you can add something like this to your build.gradle to satisfy IntelliJ.

task copyConfigurationMetadata(type: Copy) {
    from(compileJava) {
        include 'META-INF/spring-configuration-metadata.json'
    }
    into "out/production/classes"
}
compileJava {
    dependsOn processResources
    finalizedBy copyConfigurationMetadata
}