passing java property file keys via maven command line

Question

I've a config.properties files under src/main/java/configs/config.properties which contains the following profile:

 <profiles>
    <profile>
        <id>default</id>
        <activation>
            <activeByDefault>true</activeByDefault>
        </activation>
        <properties>
            <no_of_files>${no_of_files}</no_of_files>
            <no_of_rows>${no_of_rows}</no_of_rows>
        </properties>
    </profile>
</profiles>

my config.properties file contains

no_of_rows = ${no_of_rows} no_of_files = ${no_of_files}

I'm using the following maven command to pass these properties via the command line

mvn exec:java -Dexec.mainClass="com.mycompany.project.App" -Dno_of_rows=4 -Dno_of_files=3

but it results into

[ERROR] Resolving expression: '${no_of_files}': Detected the following recursive expression cycle in 'no_of_files': [no_of_files] @

I've looked into other similar answers on stackoverflow but I think I'm still not getting the right way.

I need this to run the project using a bamboo job.

Answer 1

You don't need any Maven funkiness to do this:

public class App {

    public static void main(String ...args) {

        // Load value from -Dno_of_files=
        Integer noOfFiles = Integer.getInteger("no_of_files");

        // Load value from -Dno_of_rows=
        Integer noOfRows = Integer.getInteger("no_of_rows");
    }

}

The config.properties and maven profile are not needed at all.

If you really want to generate values into a properties file then that is a more complicated answer.