Hi,
 When I run the following code
several output lines are not what I expect.

I expect:
1:1:7 [red, red]
1:32:18 [yellow]
7:11:20 [orange]

but get:
1:1:7 Why is dataByCoordinate.get(k)==null here?
1:32:18 Why is dataByCoordinate.get(k)==null here?
7:11:20 Why is dataByCoordinate.get(k)==null here?

Is there something wrong with my CoordinateComparator?
Do I not understand how TreeMap works?
Something else?
Is there an easier/better way of mapping my input to output?

Can I safely ignore the warning: Type safety: The expression
of type TestMapping.CoordinateComparator needs unchecked
conversion to conform to Comparator<? super String>

Thanks
Jeff Higgins

import java.util.ArrayList;
import java.util.Comparator;
import java.util.TreeMap;

public class TestMapping {

 public static void main(String[] args)
 {
   ArrayList<String> metCriteria = new ArrayList<String>();
   metCriteria.add("black 1:1:1 1:1:1 1:1:2 1:1:2 1:1:3 13:13:1");
   metCriteria.add("brown 13:13:1 14:20:21 16:5:7");
   metCriteria.add("red 1:1:1 1:1:2 1:1:2 1:1:3 1:1:3 1:1:3 1:1:4" +
   " 1:1:5 1:1:5 1:1:6 1:1:7 1:1:7 13:13:1 24:49:7");
   metCriteria.add("orange 5:32:37 7:11:20 7:20:36 12:18:5 19:13:5");
   metCriteria.add("yellow 1:7:14 1:32:18");
   metCriteria.add("green 24:49:7 41:16:14");
   metCriteria.add("blue 2:38:18 19:13:5");
   metCriteria.add("violet 19:13:5 24:49:7 42:24:31 72:3:19");
   metCriteria.add("gray 1:2:6 44:13:11 61:2:17 70:2:4");
   metCriteria.add("white 1:2:6 9:9:9");

   TreeMap<String,ArrayList<String>> dataByCoordinate =
     new TreeMap<String,ArrayList<String>>(
         new CoordinateComparator());

   for(String line : metCriteria)
   {
     String[] a = line.split(" ",2);
     String[] b = a[1].split(" ");
     for(int i = 0; i < b.length; i++)
       if(dataByCoordinate.containsKey(b[i]))
       {
         dataByCoordinate.get(b[i]).add(a[0]);
       }
       else
       {
         dataByCoordinate.put(b[i], new ArrayList<String>());
         dataByCoordinate.get(b[i]).add(a[0]);
       }
   }
   for(String k : dataByCoordinate.keySet())
   {
     if(dataByCoordinate.get(k) != null)
     {
       System.out.println(k + " " +
         dataByCoordinate.get(k).toString());
     }
     else
     {
       System.out.println(k +
         " Why is dataByCoordinate.get(k)==null here?");
     }
   }

 }

 static class CoordinateComparator implements Comparator
 {
   public final int compare ( Object o1, Object o2 )
   {
     String s1 = ((String) o1);
     String s2 = ((String) o2);

     String[] sa = s1.split(":");
     long[] a = new long[3];
     a[0] = Long.valueOf(sa[0]);
     a[1] = Long.valueOf(sa[1]);
     a[2] = Long.valueOf(sa[2]);

     String[] sb = s2.split(":");
     long[] b = new long[3];
     b[0] = Long.valueOf(sb[0]);
     b[1] = Long.valueOf(sb[1]);
     b[2] = Long.valueOf(sb[2]);

     long[] c = new long[3];
     c[0] = signum(a[0] - b[0]);
     c[1] = signum(a[1] - b[1]);
     c[2] = signum(a[2] - b[2]);

     if(c[0] < 0)
     {
       return -1;
     }
     else if(c[0]==0 && c[1]==0 && c[2]<0)
     {
       return -1;
     }
     else if(c[0]==0 && c[1]==0 && c[2]==0)
     {
       return 0;
     }
     else if(c[0]==0 && c[1]==0 && c[2]>0)
     {
       return 1;
     }
     else
     {
       return 1;
     }
   }

   static final int signum ( long diff )
   {
     if ( diff > 0 ) return 1;
     if ( diff < 0 ) return -1;
     else return 0;
   }
 }
}