after define a property file in idea 10.5 when i try to use it,compiler show me Null Pointer Exception!I try anything that i think fix it among change property file path,... here is the code that i write: thanks. beginner programmer!!!
public class MainDlg{
    Properties properties=new Properties();
    public MainDlg() {
        try {
            InputStream reader=MainDlg.class.getResourceAsStream("propFile");
            properties.load(reader);