Util How to get top 10 in a Hashmap

Hi there!

If you have a custom coded Economy system and want to get the highest credits that players have, instance a top 10 best players with the most credits, then this is the topic for you!

I bring you not a lib, but a simple piece of code that can be used in a command!

WARNING: If you do not have at least more than 10 values in your HashMap, errors will occur!

Code:java

   if(commandLabel.equalsIgnoreCase("topplayer")){
   if(sender instanceof Player){
   Player player = (Player)sender;
   player.sendMessage(ChatColor.GOLD + "===== Top 10 players ===== ");
 
 
          class ValueComparator implements Comparator<String> {
 
              Map<String, Integer> base;
              public ValueComparator(HashMap<String, Integer> map) {
                  this.base = map;
              }
 
              public int compare(String a, String b) {
                  if (base.get(a) >= base.get(b)) {
                      return -1;
                  } else {
                      return 1;
                  }
              }
          }
 
 
          ValueComparator bvc =  new ValueComparator(yourmap);
          TreeMap<String, Integer> sorted_map = new TreeMap<String, Integer>(bvc);
           sorted_map.putAll(yourmap);
 
          for(int i = 1; i < 11; i ++){
              Entry<String, Integer> e = sorted_map.pollFirstEntry();
              String pname = e.getKey();
              int score = e.getValue();
              player.sendMessage(i + ". " + ChatColor.GOLD  + pname + ": " + ChatColor.WHITE + score);
          }
 
   }
    }

Code:java

            class ValueComparator implements Comparator<String> {
 
                Map<String, Integer> base;
                public ValueComparator(HashMap<String, Integer> map) {
                    this.base = map;
                }
 
                public int compare(String a, String b) {
                    if (base.get(a) >= base.get(b)) {
                        return -1;
                    } else {
                        return 1;
                    }
                }
            }

This sorts the map that you specify!

Code:java

            ValueComparator bvc =  new ValueComparator(yourmap);
            TreeMap<String, Integer> sorted_map = new TreeMap<String, Integer>(bvc);
            sorted_map.putAll(yourmap);

ValueComparator sorts your map and the TreeMap stores the sorted data!

Code:java

            for(int i = 1; i < 11; i ++){
                Entry<String, Integer> e = sorted_map.pollFirstEntry();
                String pname = e.getKey();
                int score = e.getValue();
                player.sendMessage(i + ". " + ChatColor.GOLD  + pname + ": " + ChatColor.WHITE + score);
            }

Here we finally get the top 10! If you want change the top players, just change the 11 to something like 4 to get the top 3!

Examples:

Top 5 =

Code:

for(int i = 1; i < 6; i ++){

Top 20 =

Code:

for(int i = 1; i < 21; i ++){

Top 3 =

Code:

for(int i = 1; i < 4; i ++){

Please hit the LIKE button if this supported you in ANY way or if you think this is a USEFUL topic! This helped me out a plenty!

~mrgreen33gamer

 

mrgreen33gamer
Did you really just ask people how to do this, and then you post a tutorial about it?
http://forums.bukkit.org/threads/top-player-help-hashmap.325589/

This section is for Bukkit tutorials anyways, this is clearly a Java tutorial.

 

mrgreen33gamer This tutorial is ok i woud recommend u to explain more.

I just tried it in a Hello World programm with 8 Values an it works out problem

 

The like farming is a tad bit too apparent in this one

 

Did you just copy paste this from stackoverflow/ someone who pasted it from stack overflow?, Just get the score, save that to a list, then get the player, set that into the list, sort the scores, then reverse them

 

Good job copy-pasting stirante's code, without even explaining how it works.
http://forums.bukkit.org/threads/sorting-hashmaps.138359/

threads like this... just ew

 

Yes :/. Is that a problem? Because I figured it would help a lot more people than just benefit my needs.

 

mrgreen33gamer
The thread you posted for help itself can help people already. No need to make a tutorial about it.

 

Yes, that is a problem

 

Is this really a UTIL?

 

Why would you reverse it after? Surely you can figure out how to sort in the correct order the first time... Because, well, that's what sorting is: to put things in order.