Overloading TreeMap Comparator

Question

I am trying to have a common comparator. Inside the comparator, I am overloading the comparing function. It works fine, but gives a typesafe warning. Is there anyway to overcome it?
public class KeyComparator implements Comparator
     private int keyType;
     public KeyComparator(int keyType)
          this.keyType = keyType;
     public int compare(Object o1, Object o2)
          int rtnCompare = -999;
          if (this.keyType == 1)
               {rtnCompare = check(((KeyRecord)o1).getC(), ((KeyRecord)o2).getC());}
          else if (this.keyType == 2)
               {rtnCompare = check (((KeyRecord2)o1).getE(), ((KeyRecord2)o2).getE(), ((KeyRecord2)o1).getS(), ((KeyRecord2)o2).getS());}
          else if (this.keyType == 3)
               {rtnCompare = check (((KeyRecord3)o1).getsC(), ((KeyRecord3)o2).getsC());}
          return rtnCompare;     
     //Overload
     //For KeyType = 1
     private int check(String a, String b)
          int rtn = a.compareTo(b);     
          return rtn;
     //For KeyType = 2     
     private int check(short a1, short a2, short b1, short b2)
          int rtn = -999;
          if (a1 < a2) {rtn = -1;}
          else if (a1 > a2){rtn =  1;}
          else if ((a1 == a2)&& (b1 < b2)) {rtn =  -1;}
          else if ((a1 == a2)&& (b1 > b2)) {rtn =  1;}
          else if ((a1 == a2)&& (b1 == b2)) {rtn =  0;}
          return rtn;
     //For KeyType = 3
     private int check(int a, int b)
          int rtn = -999;
          if (a < b) {rtn = -1;}
          else if (a > b){rtn =  1;}
          else {rtn =  0;}
          return rtn;
}Thanks in advance.

Answer 1

Thanks for the response.
I had tried like you pointed out as below:
public class KeyComparator implements Comparator<KeyRecord>
     private int keyType;
     public KeyComparator(int keyType)
          this.keyType = keyType;
     public int compare(<KeyRecord> o1, <KeyRecord> o2)
     {//codeKeyRecord, KeyRecord2, KeyRecord3 are all separate types. Hence it gives
error "Cannot cast to KeyRecord" for KeyRecord2 & KeyRecord3
fields. This is the problem I am having. Please advise.