frequency of each word in a string in java code example

Example: how to find frequency of each word in string in java

HOW TO COUNT OCCURRENCE OF THE WORDS IN STRING 
(It can also be solved by using nested for loops...)

String str = "I am happy and why not and why are you not happy you should be";
   String [] arr = str.split(" ");
   Map<String, Integer> map = new HashMap<>();

   for (int i=0 ; i < arr.length ; i++){
       if (!map.containsKey(arr[i])){
            map.put(arr[i],1);
           } else{
         map.put(arr[i],map.get(arr[i])+1);
        }
        }
     for(Map.Entry<String, Integer> each : map.entrySet()){

    System.out.println(each.getKey()+" occures " + each.getValue() + " times");
    }