Sorting a multi dimensional character array in Java

I have a multi dimensional String array process[100][2] like following :

Y B

C D

A B

B C

F E

E Y

F D

Y X

E G

I want to sort it on the first column letter so that the final result will look so :

A B

B C

C D

E Y

E G

F E

开发者_如何学运维F D

Y B

Y X I've tried using the below code but that does not do the trick :

Arrays.sort(process, new Comparator<String[]>() {
        @Override

        public int compare(final String[] entry1, final String[] entry2) {
                final String time1 = entry1[0];
                final String time2 = entry2[0];
                return time1.compareTo(time2);

        }
});

The output I get is :

A B

B C

C D

E Y

F E

Y B

E G

F D

Y X

---

The following unit test demonstrates a working Comparator implementation. The test prints out the result as well.

import java.util.Arrays;
import java.util.Comparator;

import junit.framework.TestCase;

public class ArrayTest extends TestCase {

    public class Sorter implements Comparator {
        public int compare(Object o1, Object o2){
            String[] arrayOne = (String[])o1;
            String[] arrayTwo = (String[])o2;
            return arrayOne[0].compareTo(arrayTwo[0]);
        }
    }

    public void testSort() {
        String[][] testData = {
                {"Y", "B"},
                {"C", "D"},
                {"A", "B"},
                {"B", "C"},
                {"F", "E"},
                {"E", "Y"},
        };

        Arrays.sort(testData, new Sorter());

        String[][] expectedOutput = {
                {"A", "B"},
                {"B", "C"},
                {"C", "D"},
                {"E", "Y"},
                {"F", "E"},
                {"Y", "B"},
        };

        for(int i = 0; i < testData.length; ++i) {            
            System.out.println(testData[i][0] + " " + testData[i][1]);
            assertEquals(expectedOutput[i][0], testData[i][0]);
            assertEquals(expectedOutput[i][1], testData[i][1]);            
        }
    }
}

---

This code (identical comparator) works as expected:

    String[][] arr = {{"B","L"},{"C","M"},{"Z","N"}};

    Arrays.sort(arr, new Comparator<String[]>() {
        @Override
        public int compare(final String[] entry1, final String[] entry2) {
            final String time1 = entry1[0];
            final String time2 = entry2[0];
            return time1.compareTo(time2);
        }
    });

Your problem must be somewhere else.

---

You would probably be best off putting both of the characters in the same element for each row. Then, when you needed the separate characters, use

String firstCharacter = myString.charAt(0);
String secondCharacter = myString.charAt(1);

and you can sort your one-dimensional array however you like.