You could use a Map which you then sort using a self-written comparator (I stole the code from this thread), this way you don't have to pre-define what characters to count (as you would with arrays).
This would look something like this:
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Map;
import java.util.TreeMap;
public class CountCharsFromFile {
    static BufferedReader b;
    public static void main(String[] args) {
        try {
            FileReader fr = new FileReader("C:\\test.txt");
            b = new BufferedReader(fr);
            Map<String, Double> count = new HashMap<String,Double>();
            ValueComparator bvc = new ValueComparator(count);
            TreeMap<String, Double> sorted_map = new TreeMap<String, Double>(bvc);
            int totalChars = 0;
            int totalWords = 0;
            String currentLine;
            while ((currentLine = b.readLine()) != null){
                for (int i = 0; i < currentLine.length(); i++) {
                    //Char count:
                    totalChars += 1;
                    //Adding all chars to the Map:
                    char currentChar = Character.toLowerCase(currentLine.charAt(i));
                    if (! count.containsKey(String.valueOf(currentChar))){
                        count.put(String.valueOf(currentChar), 1.0);
                    }else{
                        count.put(String.valueOf(currentChar), count.get(String.valueOf(currentChar)) + 1);
                    }
                }
                //Counting words:
                String[] currentLineSplit= currentLine.split("\\s+");
                for (String string : currentLineSplit) {
                    totalWords += 1;
                }
            }
            sorted_map.putAll(count);
            //Output:
            System.out.println("Words: " + totalWords);
            System.out.println("Chars: " + totalChars);
            System.out.println(sorted_map.toString());
        } catch (FileNotFoundException e) {
            System.err.println("Error, file not found!");
            e.printStackTrace();
        } catch (IOException e) {
            System.err.println("Error reading file!");
            e.printStackTrace();
        }finally{
            try {
                b.close();
            } catch (IOException e) {
                System.err.println("Couldn't close the BufferedReader!");
                e.printStackTrace();
            }
        }
    }
}
//comparator class:
class ValueComparator implements Comparator<String> {
    Map<String, Double> base;
    public ValueComparator(Map<String, Double> base) {
        this.base = base;
    }
    // Note: this comparator imposes orderings that are inconsistent with
    // equals.
    public int compare(String a, String b) {
        if (base.get(a) >= base.get(b)) {
            return -1;
        } else {
            return 1;
        } // returning 0 would merge keys
    }
}
Output looks like this:
Words: 9
Chars: 59
{ =16.0, h=7.0, i=5.0, r=4.0, c=4.0, �=3.0, s=3.0, o=3.0, l=3.0, f=3.0, ,=2.0, w=1.0, u=1.0, n=1.0, m=1.0, b=1.0, a=1.0}
The output of "sorted_map.toString()" is not really nice, so I wrote a quick output method:
static void output(TreeMap<String, Double> sm) {
        String map = sm.toString();
        if (map.length() > 2) { //If the map is empty it looks like this: {}
            map = map.substring(1, map.length() - 1); //cutting the leading and closing { }
            String[] charCount = map.split(", "); //Splitting
            //And then formatting:
            for (String string : charCount) {
                if (string.charAt(0) == ' ') {
                    string = string.substring(1, string.length() - 2);
                    string = " " + string.substring(0, 1) + " " + string.substring(1, string.length());
                    System.out.println("SPACE" + string);
                } else {
                    string = string.substring(0, string.length() - 2);
                    string = string.substring(0, 1) + " " + string.substring(1, 2) + " "
                            + string.substring(2, string.length());
                    System.out.println(string);
                }
            }
        }
    }
Which you call like so:
    System.out.println("Words: " + totalWords);
    System.out.println("Chars: " + totalChars);
    System.out.println();
    //System.out.println(sorted_map.toString()); <--- old
    output(sorted_map);
And the Output looks like this:
Words: 9
Chars: 60
SPACE = 8
R = 6
T = 5
E = 5
A = 5
N = 3
U = 2
O = 2
M = 2
L = 2
I = 2
H = 2
. = 1
Z = 1
Y = 1
X = 1
W = 1
V = 1
S = 1
Q = 1
P = 1
K = 1
J = 1
G = 1
F = 1
D = 1
C = 1
B = 1
And there you go, it got a little bit messy (the comparator breaks the "TreeMap.get" method so I had to build a workaround using substrings) but I hope that this will somewhat help you :)