non-static method cannot be referenced from a static context.

I have the line of code in a class X:
{code}Database.addIngenieur(new Ingenieur(naam,voornaam,paswoord,ranking,email,tel efoon));{code}


In my Database class I have the method addIngenieur:
{code}public void addIngenieur(Ingenieur deIngenieur)
{
ingenieurs.add(deIngenieur);
}{code}

which should add the ingenieur to the arraylist ingenieurs.

My class Ingenieur looks like the following:

{code}
public class Ingenieur
{
private String naam;
private String voornaam;
private String ranking;
private String email;
private String telefoonnummer;
private String nota;
private String paswoord;



public Ingenieur(String deNaam, String deVoornaam, String hetPaswoord, String deRanking, String deEmail, String hetTelefoonnummer)
{
naam = deNaam;
voornaam = deVoornaam;
ranking = deRanking;
email = deEmail;
telefoonnummer = hetTelefoonnummer;
paswoord = hetPaswoord;
nota = "";
}

//Some other methods below...

}
{code}

But it gives me the following error in class X: non-static method addIngenieur(Ingenieur) cannot be referenced from a static context.

I just don´t see the error which should be obvious to a real programmer.
Can anyone help me?

Best Regards

addIngenieur is not a static method, yet you are trying to call it on it's class, rather than an instance of the class.

You can access only static methods with out objects.Hence if you want to do so,Change the method in static mode.

i think you should create the class object
if you change method to static, variable used also need to be changed to static

if a method is not static the u have to call it using object of class.
if u directly want to call a method using class name then declare it as static.
You can not call non static method from static context.

Just go through the following page, it may help you to have a better idea about the static members in Java.

The Essence of OOP using Java: Static Members