HashMap Collection in Java

package collections;

import java.util.HashMap;
import java.util.Map;

public class HashMapEx {

public static void main(String[] args) {

//Here String is key and Integer is value
Map<String,Integer> hm=new HashMap<String,Integer>();

//Enter values to table from Command line arguments
for(String s:args)
{
Integer a=hm.get(s);
hm.put(s,(a==null)?1:a+1);
}
System.out.println("Size: "+hm.size());
System.out.println("Distinct Words: "+hm);


}

}