Maven onejar plugin, get a properties file

Question

I am using the Maven onejar plugin (https://code.google.com/p/onejar-maven-plugin/) to create an uberjar.

I want to access a properties file which is in the root of my classpath like this:

Properties prop = new Properties();

        try {
            prop.load(new FileInputStream("Db.properties"));

            driver = prop.getProperty("driver");
            url = prop.getProperty("url");
            username = prop.getProperty("username");
            password = prop.getProperty("password");

        } catch (IOException ex) {
            LOG.debug(ex.toString());
        }   

        conn = null;

My log4j.properties file which is in the same directory is found because i can do logging... What is my problem? :/ But the Db.properties isnt found.

Answer 1

FileInputStream is used to load resources from files located on the file system. Files inside a jar are not on the file system. You need to use a different InputStream.

For this case, using the ClassLoader#getResourceAsStream(String) method would be advised. It returns an InputStream resource found on the classpath. Something like:

InputStream is = getClass().getClassLoader().getResourceAsStream("/Db.properties");

should work. Or for convenience:

InputStream is = getClass().getResourceAsStream("/Db.properties");

Of note, the reason the log4j.properties works is because Log4j by design can load configuration files in the root classpath.