Java skips if-clause [duplicate]

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I'm sorry, but my code is in german! (I hope that's not a problem!)

My problem is, that even if (at the bottom) the input is "Ja"("Yes") or "ja"("yes") Java just skips it and does the else-clause!

Thanks to everyone in advance!

import java.util.Scanner;
public class Pizza {
    private double preis;
    private int anzahl;

    public Pizza() {
        preis = 5.50;
        anzahl = 0;
    }

    public void hinzufuegen(int tmp) {
        anzahl = anzahl + tmp;
    }

    public void entfernen(int tmp) {
        anzahl = anzahl - tmp;
    }

    public void drucken() {
        System.out.println("Pizzen: " + anzahl + " Preis: " + preis * anzahl);
    }

    public static void main(String[] args) {
        Pizza Margherita = new Pizza();
        Scanner scan = new Scanner(System.in);

        System.out.print("Wie viele Pizzen willst du? ");
        Margherita.anzahl = scan.nextInt();

        System.out.print("Bist du dir sicher, dass du " + Margherita.anzahl + " Pizzen willst? ");
        String input = scan.next();

        System.out.println(input);

        if(input=="Ja" || input=="ja") {
            Margherita.drucken();
        }
        else {
            System.out.println("Schade!");
        }
    }
}