programming-examples/java/Basics/Program to sort a map by value. (Java).java

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2019-11-18 14:44:36 +01:00
/*
Sort or order a HashMap or TreeSet or any map item by value. Write a comparator
which compares by value, not by key. Entry class might hleps you here.
*/
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.Set;
import java.util.Map.Entry;
public class OrderByValue
{
public static void main(String a[])
{
Map<String, Integer> map = new HashMap<String, Integer>();
map.put("java", 20);
map.put("C++", 45);
map.put("Java2Novice", 2);
map.put("Unix", 67);
map.put("MAC", 26);
map.put("Why this kolavari", 93);
Set<Entry<String, Integer>> set = map.entrySet();
List<Entry<String, Integer>> list = new ArrayList<Entry<String, Integer>>(set);
Collections.sort( list, new Comparator<Map.Entry<String, Integer>>()
{
public int compare( Map.Entry<String, Integer> o1, Map.Entry<String, Integer> o2 )
{
return (o2.getValue()).compareTo( o1.getValue() );
}
} );
for(Map.Entry<String, Integer> entry:list)
{
System.out.println(entry.getKey()+" ==== "+entry.getValue());
}
}
}