package javacodebook.core.properties;

import java.io.*;

public class ResourceManager {

    public static InputStream getResourceAsStream(Object object,
    String resourceName) {
        ClassLoader cLoader = object.getClass().getClassLoader();
        InputStream in = null;
        if(cLoader != null) {
            in = cLoader.getResourceAsStream(resourceName);
        } else {
            in = ClassLoader.getSystemResourceAsStream(resourceName);
        }
        return in;
    }
}

--- Neue Klasse ---

package javacodebook.core.properties;

import java.util.Properties;
import java.io.InputStream;

public class Starter {

    public static void main(String[] args) throws Exception {
        // Die zu ladende Properties-Datei
        String propsFile = "javacodebook/core/properties/demo.properties";
        Properties prop = new Properties();
        // Properties aus der Datei lesen
        InputStream stream = ResourceManager.getResourceAsStream(prop, propsFile);
        prop.load(stream);

        // Ein paar Properties anzeigen
        System.out.println("width=" + prop.getProperty("width"));
        System.out.println("height=" + prop.getProperty("height"));
        System.out.println("color=" + prop.getProperty("color"));

    }
}