Where is getResourceAsStream("file") searching when running from a test?

Question

I'm struggling to create a test to verify a ServletListener that loads a properties file. I've tested when running the application that it works fine and it finds the file in the classpath. But I don't know how to create a test for it. My idea is to create a temp file with a test property and then verify the property is put into the System properties. But I always fail to create the file in the right place.

I've tried creating the file in /target/test-classes or directly in the root of the application but it never finds it. Any idea?

This is the code I'm trying to test:

public class PropertyReadingListener implements ServletContextListener {

    public static final String PROFILES_PROPERTIES = "profiles.properties";

    @Override
    public void contextDestroyed(ServletContextEvent event) {
    }

    @Override
    public void contextInitialized(ServletContextEvent event) {
        Properties propsFromFile = new Properties();
        try {
            propsFromFile.load(getClass().getResourceAsStream(PROFILES_PROPERTIES));
        } catch (final Exception e) {
            log.warn("Unable to find {}, using default profile", PROFILES_PROPERTIES);
        }
        propsFromFile.stringPropertyNames().stream()
            .filter(prop -> System.getProperty(prop) == null)
            .forEach(prop -> System.setProperty(prop, propsFromFile.getProperty(prop)));
    }
}

Thanks.

Answer 1

See Different ways of loading a file as an InputStream

Basically when you do a getClass().getResourceAsStream it looks in the package of that class for the file.. so if your PropertyReadingListener is in com.company.listeners.PropertyReadingListener then it will look in com/company/listeners for the property file.

For testability, I would pass in an InputStream into the listener that way the test can create the input stream in a convienent way and the actual user of the class in code can pass in the InputStream returned from getResourceAsStream