The code snippet below shows how one can read a text file packed in a JAR file.

Java Code:
public class FileUtils{

  public static List<String> readTextFromJar(String s) {
    InputStream is = null;
    BufferedReader br = null;
    String line;
    ArrayList<String> list = new ArrayList<String>();

    try { 
      is = FileUtils.class.getResourceAsStream(s);
      br = new BufferedReader(new InputStreamReader(is));
      while (null != (line = br.readLine())) {
         list.add(line);
      }
    }
    catch (Exception e) {
      e.printStackTrace();
    }
    finally {
      try {
        if (br != null) br.close();
        if (is != null) is.close();
      }
      catch (IOException e) {
        e.printStackTrace();
      }
    }
    return list;
  }

  public static void main(String args[]) throws IOException{
    List<String> list = FileUtils.readTextFromJar("/datafile1.txt");
    Iterator<String> it = list.iterator();
    while(it.hasNext()) {
      System.out.println(it.next());
    }

    list = FileUtils.readTextFromJar("/test/datafile2.txt");
    it = list.iterator();
    while(it.hasNext()) {
      System.out.println(it.next());
    }
  }
}