Question

I am attempting to sort an ArrayList of TokenDoubleCounters (my custom object). In TokenDoubleCounter, I have implemented equals and compareTo as below:

public class TokenDoubleCounter implements Comparable<TokenDoubleCounter> {
private String word;
private double count;

public boolean equals(Object o) {
    if (o instanceof TokenDoubleCounter) {
        TokenDoubleCounter other = (TokenDoubleCounter) o;
        if (other.word.equals(this.word) && other.count == this.count)
            return true;
    }
    return false;
}

public int compareTo(TokenDoubleCounter other) {
    double result = this.count - other.getCount();
    if (result > 0.0) 
        return 1;
    if (result < 0.0) 
        return -1;
    return this.word.compareTo(other.getWord());
}

    //rest of class omitted
}

These objects are created and sorted in the following function call:

    public List<TokenDoubleCounter> chiSquareValueAll(int cl, int cl2) {
    List<TokenDoubleCounter> list = new ArrayList<TokenDoubleCounter>();

    for (String word : map.keySet()) {
                                                        //chiSquareValue2 returns a double
        list.add(new TokenDoubleCounter(word, chiSquareValue2(cl,cl2,word)));       
    }
    Collections.sort(list, Collections.reverseOrder());
    return list;
}

Finally, iterating through these results, I write these to file:

    public boolean printChiSquare(PrintWriter out, int cl, int cl2) {
    for (TokenDoubleCounter tdc : this.chiSquareValueAll(cl,cl2)) {
        if (tdc.getCount() > 2.7) {
             //getWord() returns string value "word"  and getCount() returns double value "count"
            out.write(tdc.getWord() + "," + tdc.getCount() + "\n");

        }
    }
    return true;
}

The results were somewhat surprising to me as they do not seem to be in the order I requested:

word,8.937254901960785
word,8.937254901960785
word,8.937254901960785
word,5.460792811839323
word,4.746170542635659
word,4.382692307692308
word,4.382692307692308
word,4.382692307692308
word,4.382692307692308
word,4.382692307692308
word,4.382692307692308
word,4.382692307692308
word,8.937254901960785
word,8.937254901960785
word,8.937254901960785
word,8.937254901960785
word,8.937254901960785
word,8.937254901960785

word,8.937254901960785
word,5.460792811839323
word,4.746170542635659
word,4.746170542635659
word,4.746170542635659
word,4.382692307692308

…

What am I missing? And let me know if you need additional details.

Also, I should add that all of the entries “word” are actually strings of varying length, etc., but I don’t think that’s relevant.

Thanks for the help.

Answer 1

Try this:

public int compareTo(TokenDoubleCounter other) {
    int result = Double.compare(count, other.count);
    return result != 0 ? result : word.compareTo(other.word);
}