Question

*Please forgive the intricate title*

Background

/pom.xml

...
<foo.bar>stackoverflow</foo.bar>
...

/src/main/resources/config.properties

...
foo.bar=${foo.bar}
...

Config.java

...

public final static String FOO_BAR;

static {
    try {
        InputStream stream = Config.class.getResourceAsStream("/config.properties");
        Properties properties = new Properties();
        properties.load(stream);
        FOO_BAR = properties.getProperty("foo.bar");
    } catch (IOException e) {
        e.printStackTrace();
    }
}

...

Question

In /src/main/java, I’m using Config.FOO_BAR in MyClass.java. If I want to test MyClass in a /src/test/java folder using JUnit with MyClassTest.java, how can I load the properties so that the Config.FOO_BAR constant get initialized?

I tried to add a hardly-written config.properties within /src/test/resources with foo.bar=stackoverflow, but it still can’t get initialized.

Answer 1

I could make it work by changing some in your pom.xml and your Config.java.

Add these lines to your pom.xml:

<project>
    ...
    <build>
        <resources>
            <resource>
                <directory>src/main/resources</directory>
                <filtering>true</filtering>
            </resource>
        </resources>
    </build>
</project>

And change the order of some lines in Config.java:

public class Config {
    public final static String FOO_BAR;

    static {
        InputStream stream = Config.class.getResourceAsStream("/config.properties");
        Properties properties = new Properties();
        try {
            properties.load(stream);
        } catch (IOException e) {
            e.printStackTrace();
            // You will have to take some action here...
        }
        // What if properties was not loaded correctly... You will get null back
        FOO_BAR = properties.getProperty("foo.bar");
    }

    public static void main(String[] args) {
        System.out.format("FOO_BAR = %s", FOO_BAR);
    }
}

Output if running Config:

FOO_BAR = stackoverflow

Disclaimer

I am not sure what purpose you have with setting these static config values. I just made it work.

---

Edit after comment

Added a simple JUnit test to src/test/java/:

package com.stackoverflow;

import org.junit.Test;

import static org.junit.Assert.assertEquals;

/**
 * @author maba, 2012-09-25
 */
public class SimpleTest {

    @Test
    public void testConfigValue() {
        assertEquals("stackoverflow", Config.FOO_BAR);
    }
}

No problems with this test.