InputStream is null

In the program I am working on, I have

String cwd;
String file_separator;

public ConfigLoader()
{
    cwd = get_cwd();
    file_separator = get_file_separator();

    try
    {
        Properties c = new Properties();

        InputStream in = this.getClass().getClassLoader().getResourceAsStream(cwd + 
            file_separator + "data" + file_separator + "configuration.properties");

        c.load(in);
    }
    except (Exception e) { e.printStackTrace(); }
}

public String get_file_separator()
{
    File f = new File("");
    return f.separator;
}

public String get_cwd()
{
    File cwd = new File("");
    return cwd.getAbsolutePath();
}

      

        
        
        
      

    

For some reason, c.load(in);

calls a NullPointerException

. The exception is in == NULL

being true. I can't figure out why because

System.out.println(cwd + file_separator + "data" + file_separator +
    "configuration.properties");

      

        
        
        
      

    

prints

/users/labnet/st10/jjb127/workspace/Brewer-Client/data/configuration.properties

      

        
        
        
      

    

which is the location of the file I want to use.

Thoughts?