How To Course Of Report Listing Inwards Contrary Guild Inwards Coffee Collection Framework Amongst Example

Java Collection Framework provides a convenient contrary comparator, to form List of objects inwards contrary order.  You tin obtain contrary Comparator, past times calling Collections.reverseOrder(), which past times default form List of Integer inwards contrary numeric companionship too List of String inwards contrary alphabetic order. It truly contrary natural ordering of objects imposed past times Comparable interface. Apart from this method, Collections degree likewise provides an overloaded method Collections.reverseOrder(Comparator cmp), which takes a Comparator, too form List on contrary companionship of that Comparator. So side past times side fourth dimension if y'all postulate to form your Collection in contrary order, y'all don’t postulate to write whatsoever extra comparator past times yourself, y'all tin straight leverage contrary comparator provided past times java.util.Collections class. It is every bit uncomplicated every bit calling Collections.sort() method providing comparator wrapped into Collections.reverseOrder() method. By using these 2 methods, y'all tin form whatsoever List implementation e.g. ArrayList, LinkedList or Vector inwards Java.

Java Program to form ArrayList inwards contrary Order

Here is consummate code for sorting List inwards contrary companionship inwards Java. In this plan nosotros cause got 2 list, List<Integer> too List<String> too nosotros are sorting them outset inwards natural companionship too than inwards at that spot contrary companionship past times using Collections.reverseOrder() method.

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collections;

import java.util.List;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

/**

  * Java Program to form List of object inwards contrary order. We volition run into examples of

  * sorting Array List inwards contrary companionship of both default ordering every bit good every bit whatsoever

  * custom ordering imposed past times Compartor.

  *

  * @author Javin Paul

  */

public class CollectionSorting {

 

    private static final Logger logger = LoggerFactory.getLogger(CollectionSorting.class);

  

    public static void main(String args[]) {

      

        // Creating too initializing Collection to form inwards contrary order

        // Integer volition hold upwards sorted inwards contrary numeric order

        List<Integer> collection = new ArrayList<Integer>();

        collection.add(101);

        collection.add(201);

        collection.add(105);

        collection.add(302);

      

        logger.debug("Current companionship inwards Collection : " + collection);

      

        // Sorting Collection inwards contrary order

        Collections.sort(collection, Collections.reverseOrder());

      

        logger.debug("Sorted on Reverse companionship inwards Collection : {}", collection);

      

        // Sorting List of String inwards contrary Order

        List<String> alphabets = Arrays.asList("A", "B", "C", "D");

      

        logger.debug("Current companionship inwards List of String : {}", alphabets);

      

        // Sorting List inwards contrary Order

        Collections.sort(alphabets, Collections.reverseOrder());

      

        logger.debug("List of String sorted inwards contrary companionship {}", alphabets);

    }

 

}

Output

 [main] DEBUG CollectionSorting  - Current companionship inwards Collection : [101, 201, 105, 302]

 [main] DEBUG CollectionSorting  - Sorted on Reverse companionship inwards Collection : [302, 201, 105, 101]

[main] DEBUG CollectionSorting  - Current companionship inwards List of String : [A, B, C, D]

[main] DEBUG CollectionSorting  - List of String sorted inwards contrary companionship [D, C, B, A]

That's all on How to form List of Strings or Integers inwards to revrese order. You tin likewise piece of occupation same technique to form whatsoever List into contrary companionship of at that spot natural ordering or custom ordering imposed past times whatsoever Comparator inwards Java.

Further Learning
Java In-Depth: Become a Complete Java Engineer
tutorial)
How to form an ArrayList inwards ascending too descending companionship inwards Java? (tutorial)
Difference betwixt ArrayList too HashSet inwards Java? (answer)
The divergence betwixt TreeMap too TreeSet inwards Java? (answer)
The divergence betwixt HashMap too ConcurrentHashMap inwards Java? (answer)
The divergence betwixt HashSet too TreeSet inwards Java? (answer)
The divergence betwixt ArrayList too LinkedList inwards Java? (answer)
The divergence betwixt Vector too ArrayList inwards Java? (answer)

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