class SortByValue implements Comparator<Map.Entry<Integer, Integer>>{
@Override
public int compare( Map.Entry<Integer,Integer> entry1, Map.Entry<Integer,Integer> entry2){
return (entry2.getValue()).compareTo( entry1.getValue() );
}
}
|
OUTPUT will be >
/*OUTPUT
Before sorting by value: 1=2 2=1 3=9 4=8
After sorting by value(descending): 3=9 4=8 1=2 2=1
*/
|
Full program >
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;
class SortByValue implements Comparator<Map.Entry<Integer, Integer>>{
@Override
public int compare( Map.Entry<Integer, Integer> entry1, Map.Entry<Integer, Integer> entry2 ){
return (entry2.getValue()).compareTo( entry1.getValue() );
}
}
/**
* @author AnkitMittal
* Copyright (c), AnkitMittal JavaMadeSoEasy.com
* Main class
*/
public class SortMapByValueDescending {
public static void main(String...a){
Map<Integer, Integer> map = new HashMap<Integer, Integer>();
map.put(1, 2);
map.put(2, 1);
map.put(3, 9);
map.put(4, 8);
Set<Entry<Integer, Integer>> set = map.entrySet();
List<Entry<Integer, Integer>> list = new ArrayList<Entry<Integer, Integer>>(set);
System.out.print("Before sorting by value: ");
for(Map.Entry<Integer, Integer> entry:list){
System.out.print(entry.getKey()+"="+entry.getValue()+" ");
}
Collections.sort(list, new SortByValue());
System.out.print("\nAfter sorting by value(descending): ");
for(Map.Entry<Integer, Integer> entry:list)
System.out.print(entry.getKey()+"="+entry.getValue()+" ");
}
}
/*OUTPUT
Before sorting by value: 1=2 2=1 3=9 4=8
After sorting by value(descending): 3=9 4=8 1=2 2=1
*/
|
RELATED LINKS>