Oto moja klasa:
import java.util.Hashtable;
public final class Cennik {
private final static Cennik c = new Cennik();
private Cennik() {}
public static Cennik getCennik() {
return c;
}
public void set(String produkt, double cena) {
Hashtable ht = new Hashtable();
double d = cena;
String s = produkt;
ht.put(s, new Double(d));
Object o = ht.get(s);
Double val = (Double) o;
double dv = val.doubleValue();
}
}
Przy kompilacji wyświetla się:
Note: Cennik.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.