How to Sort a HashMap by Value in Java?

To Sort a HashMap by Value in Java, we are perform following step :-

HashMap store items in “key, value” pairs. To get a value from the HashMap, we use the key corresponding to that entry.
First we create the hashmap object and store the key, value data.
From h.entrySet() method take only unique hashmap key data.
Now pass this Set() data to arraylist class.
Now use the Collections.sort() method to sort the data.
From Comparator interface, we call the compare() method for customized sorting.
This method compare from the first value to second value.

Syntax :- (m1.getValue()).compareTo(m2.getValue()

After sorting this list,pass to for loop to fetch the data from map.getKey() and map.getValue().

				
					import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

public class OrderByValue {
	public static void main(String[] args) {
		HashMap<String, Integer> h = new HashMap<String, Integer>();
		h.put("java", 35);
		h.put("spring", 3);
		h.put("jsp", 24);
		h.put("core", 2);
		h.put("servlet", 89);
		Set<Entry<String, Integer>> st = h.entrySet();
		List<Entry<String, Integer>> list = new ArrayList<Entry<String, Integer>>(st);

		Collections.sort(list, new Comparator<Map.Entry<String, Integer>>() {
			public int compare(Map.Entry<String, Integer> m1, Map.Entry<String, Integer> m2) {
				return (m1.getValue()).compareTo(m2.getValue());
			}
		});
		System.out.println("sort by value :- ");
		for (Map.Entry<String, Integer> map : list) {
			System.out.println("key :- "+map.getKey() + " ,value :- " + map.getValue());
		}
	}
}

Output :-
sort by value :-
key :- core ,value :- 2
key :- spring ,value :- 3
key :- jsp ,value :- 24
key :- java ,value :- 35
key :- servlet ,value :- 89