Hash Map question ...

[Brian Lugo]

I have a question relating to the uniqueness of keys in HashMap. I wrote this program and apparently the HashMap seems to be accepting duplicate keys. Could some one please point out what I am doing wrong or if I am missing something?

import java.util.*;
class MyMapKeyType implements Comparable {

private int i;
public MyMapKeyType(int n) { i = n; }
public boolean equals(Object o) {
return 
(o instanceof MyType) 
&& (i == ((MyMapKeyType)o).i);
}
public int hashCode() { return i; }
public String toString() { return i + " "; }

public int compareTo(Object o) {
int i2 = ((MyMapKeyType)o).i;
return (i2 < i ? -1 : (i2 == i ? 0 : 1));
}
}
public class TestHashMap
{
public static void main(String[] args) {
Map hm = new HashMap();

MyMapKeyType a1 = new MyMapKeyType(1);
hm.put(a1, new Integer(7));
MyMapKeyType a2 = new MyMapKeyType(1);
hm.put(a2, new Integer(7));
hm.put(a1, new Integer(7));
System.out.println(hm);
hm.put("abc", new Integer(2));
hm.put("abc", new Integer(2));
System.out.println(hm);
}
}

Thanks,
Brian

[Mapraputa Is]

Are you sure your equals method should contain "(o instanceof MyType)", not "(o instanceof MyMapKeyType)" ?
-------------
Mapraputa Is, aka hashMap

[Brian Lugo]

Thanks Mapraputa !
Yep that was it. How foolish of me ...
Why does'nt the compiler correct my foolish mistakes ? No - Just kidding ...
Brian