当我运行我的代码时，我会看到一个屏幕，要求一个引用（已经编码并且工作正常）。所以当我输入IW1作为引用时，我的输出应该是IW1的细节，也就是"IW1", new troop(1, "Twisters", 200, 200))。然而，我得到了以下错误：
Exception in thread "main" java.lang.RuntimeException: Uncompilable source code - incompatible types: java.lang.String cannot be converted to java.util.HashMap<java.lang.String,OODCwk.troop>
OODCwk是软件包的名称

public String getTroopDetails(String ref)
    {
        if ("IW1".equals(ref) ){
            HashMap<String, troop> Troop= getTroopDetails(ref);
            System.out.println(Troop.get("IW1"));

        }else{
            return "!";
        } 
        return "\nNo such troop";
    }

private void setupTroop()
    {
        HashMap<String, troop>Troop= new HashMap<String, troop>();

        Troop.put("IW1", new troop(1, "Twisters", 200, 200)); 

    }

public class troop{
    int FleetRef;
    String FullName;
    int ActivationFee;
    int BattleStrength; 

    public troop(int FRef, String FName, int AFee, int BStrength)
    {
        FleetRef = FRef;
        FullName = FName;
        ActivationFee = AFee;
        BattleStrength = BStrength;
    }

    public int getFleetRef()
    {
        return FleetRef;
    }
    public String getFullName()
    {
        return FullName;
    }
    public int getActivationFee()
    {
        return ActivationFee;
    }

    public int BattleStrength()
    {
        return BattleStrength;
    }
}