How to select indicated file from properties using maven

Question

I am using java in maven project for test automation. I have two properties files:

DEV.properties (environment: DEVELOPMENT)
PROD.properties (environment: PRODUCTION)

I read this properties:

private static final Properties properties;
private static final String CONFIG_PROPERTIES_FILE = "DEV.properties";

static {
    properties = new Properties();
    InputStream inputStream = Property.class.getClassLoader().getResourceAsStream(CONFIG_PROPERTIES_FILE);
    try {
        properties.load(inputStream);
    } catch (IOException e) {
        e.printStackTrace();
    }
}

In "CONFIG_PROPERTIES_FILE" variable I can indicate which environment I want to use (DEV or PROD). How to do the same with a terminal using maven? Something like:

 private static final String CONFIG_PROPERTIES_FILE = $environment;

and in terminal:

mvn clean test $environment=DEV.properties

or:

mvn clean test $environment=PROD.properties

`static final` is for indicating a _constant_ value. But your requirement is to have it _dynamic_. This isn't possible with constants. — Seelenvirtuose, Dec 02 '22 at 11:22
Why do you need those different property files ? Apart from that you can't define the loading of a property file via environment variable... — khmarbaise, Dec 02 '22 at 14:55

Dmitry Khamitov · Accepted Answer · 2022-12-05T10:17:37.280

The following should work.

public class MyTest {
    private static final String CONFIG_PROPERTIES_FILE = System.getProperty("environment");

    static {
        var properties = new Properties();
        InputStream inputStream = MyTest.class.getResourceAsStream(CONFIG_PROPERTIES_FILE);
        try {
            properties.load(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Now, you have to run mvn like in the below example because my assumption is that you run Maven Surefire Plugin in a forked mode which is a default mode.

mvn clean test -DargLine="-Denvironment=DEV.properties"

By using the argLine you can specify system properties that you want to pass to a forked JVM. Without the argLine those -D properties will not be passed from the so-called main (mvn) JVM to a child (forked) one used by the Surefire to run the tests.

For a bit of background on that "argLine" machinery you can check out this answer (and many others) or the Maven mail thread. Both date back to 14 years ago...

How to select indicated file from properties using maven

1 Answers1