Method implementation

I am quite new to java and need help in setting up the implementation of the method in a more sophisticated way - I have written this, but was told I need to use one of the GoF patterns in order to beautify it. Some help as to what I need to do would be most appropriated

protected void setWeapon() {
        if (this.getClass().getSimpleName().equals("FighterJet")) {
            this.weapon = new GuidedMissileSystem();
            System.out.println("FighterJet " + id + " equipped with " + weapon.getClass().getSimpleName());
        } else if (this.getClass().getSimpleName().equals("AttackHelicopter")) {
            this.weapon = new GrenadeLauncher();
            System.out.println("AttackHelicopter " + id + " equipped with " + weapon.getClass().getSimpleName());
        } else if (this.getClass().getSimpleName().equals("Tank")) {
            this.weapon = new Cannon();
            System.out.println("Tank " + id + " equipped with " + weapon.getClass().getSimpleName());
        } else if (this.getClass().getSimpleName().equals("InfantryMobilityVehicle")) {
            this.weapon = new MachineGun();
            System.out.println("InfantryMobilityVehicle " + id + " equipped with " + weapon.getClass().getSimpleName());
        } else if (this.getClass().getSimpleName().equals("Warship")) {
            this.weapon = new RocketLauncher();
            System.out.println("Warship " + id + " equipped with " + weapon.getClass().getSimpleName());
        } else if (this.getClass().getSimpleName().equals("Submarine")) {
            this.weapon = new TorpedoTube();
            System.out.println("Submarine " + id + " equipped with " + weapon.getClass().getSimpleName());
        }
    }