Sorting a 2d String Array in Java

Question

I created a 2d-array in Java for a project that reads in a file, processes the data, and the prints it back out. The only problem I am having is trying to sort the 2d-array alphabetically.

This is an example of the file input:

2011 Regular Season
Boston 162 5710 875 1600 352 35 203
NY_Yankees 162 5518 867 1452 267 33 222
Texas 162 5659 855 1599 310 32 210
Detroit 162 5563 787 1540 297 34 169
St.Louis 162 5532 762 1513 308 22 162
Toronto 162 5559 743 1384 285 34 186
Cincinnati 162 5612 735 1438 264 19 183
Colorado 162 5544 735 1429 274 40 163
Arizona 162 5421 731 1357 293 37 172
Kansas_City 162 5672 730 1560 325 41 129

And this is an example of what the output looks like:

2011 Regular Season
====================
Boston:     .280 .461
NY_Yankees: .263 .444
Texas:      .283 .460
Detroit:    .277 .434
St.Louis:   .273 .425
Toronto:    .249 .413
Cincinnati: .256 .408
Colorado:   .258 .410
Arizona:    .250 .413
Kansas_City:.275 .415
====================
Big Ten Av: .266 .428

My goal is to have the team names sorted alphabetically. I have tried using the Array.sort() method as well as using a Comparator but nothing has worked. I will include the working code that I have now and any help would be great!

package problem_1;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.text.DecimalFormat;
import java.util.Arrays;
import java.util.Comparator;

public class sluggers2 {

static String specificstat[][] = new String[1000][1000]; //Create a 2-dimensional array with limits of 1000
static DecimalFormat df = new DecimalFormat(".###");//Variable to round the integers to 3 decimal places

public static void main(String args[]) { //Main method
    execute(); //Call on the function "execute" and execute it
    baseballstats(1);
}

public static String[][] execute() {
    int line = 0;
    try {
        BufferedReader in = new BufferedReader(new FileReader("stuff/input_sluggers.txt"));

        String str;
        while ((str = in.readLine()) != null) {
            if (str.trim().length() == 0) {
                continue; // Skip blank lines
            }
            specificstat[line] = str.split(" ");
            line++;
        }
        in.close();
    } catch (IOException e) {
        System.out.println("Can not open or write to the file.");
    }
    return specificstat;
}

public static void baseballstats(int teamnumber) {
    double batting_average, slugging_average = batting_average = 0;

            //Arrays.sort(specificstat[0]);
            //Tried sorting the first dimension but it didn't work

    System.out.println(specificstat[0][0] + " " + specificstat[0][1] + " " + specificstat[0][2]);
    System.out.println("====================");

    while (teamnumber <= 10) {

        double B = Integer.parseInt(specificstat[teamnumber][5]);
        double C = Integer.parseInt(specificstat[teamnumber][6]);
        double D = Integer.parseInt(specificstat[teamnumber][7]);
        double A = Integer.parseInt(specificstat[teamnumber][4]) - (B + C + D);

        double slug_avg = ((A + 2*B + 3*C + 4*D) / Integer.parseInt(specificstat[teamnumber][2]));
        double y = Integer.parseInt(specificstat[teamnumber][4]), z = Integer.parseInt(specificstat[teamnumber][2]), bat_avg = y / z;

        slugging_average = slugging_average + slug_avg;
        batting_average = batting_average + bat_avg;

        double hits = Integer.parseInt(specificstat[teamnumber][4]);
        double at_bats = Integer.parseInt(specificstat[teamnumber][2]);

        String batting = df.format(hits / at_bats), slugging = df.format(slug_avg);

        if (slugging.length() == 3)
            slugging = slugging + "0";

        if (batting.length() == 3)
            batting = batting + "0";

        System.out.println(specificstat[teamnumber][0] + ":  " +  "\t" + batting + " " + slugging);
        teamnumber++;
    }

    String big_ten_av = "\t" + df.format(batting_average / 10) + " "+ df.format(slugging_average / 10);

    System.out.println("====================");
    System.out.print("Big Ten Av: "); System.out.print(big_ten_av);
}
}

I'm relatively new to coding so any help would be much appreciated.

Answer 1

You need something like this:

Arrays.sort( specificstat, new Comparator<String[]> {
    public int compare( String[] s1, String[] s2 ) {
        return s1[0].compareTo(s2[0]);
    }
} );

Which basically says to sort the inner arrays of specificstat by comparing the first element of each of the inner arrays...

Answer 2

An alternative solution to Lucas' is to eliminate the 2d array entirely, and use an array of some class, say:

class TeamRecord implements Comparable {
  public String teamName;
  public ArrayList<Integer> stats;

  int compareTo(TeamRecord other) {
    return teamName.compareTo(other.teamName);    
  }

}

And change your:

static String specificstat[][] = new String[1000][1000];

to:

static TeamRecord specificstat[] = new TeamRecord[1000];

Then Array.sort(specificstat) will sort based on teamName.

The advantage of this approach is that it makes your data more clear, since the team name is really a different kind of thing than the stats; here the types make that immediately clear.

I've omitted code that will populate an array of that datatype, but I think you can figure it out.