Sorting out an array List using Collections

Question

I want to use the Comparator object of the Collections framework to sort out an ArrayList by an specific attribute.

I have an ArrayList called measureEviArray this array contains objects type MeasureEvi.

The class MeasureEvi has an attribute called mCoordenate which corresponds to a PointF data type.

public class MeasureEvi {

private int mIndex;                             //  
private int mOrderIndex;
private int eIndex;                             // 
private TextView mTag;                          // 
private PointF mCoordenate; 
}

What I want is to sort out that array depending on the coordenates given to each object in X (mCoordenate.x)

Is it possible to use Collections for this and get an Array Ordenate from the minor to the greatest in X axis?

I was trying to implement this way:

 Collections.sort(measureEviArray, new Comparator<MeasureEvi>() {
        @Override
        public int compare(MeasureEvi measureEvi, MeasureEvi t1) {
            return measureEvi.getmCoordenate().x.compareTo(t1.getmCoordenate().x);
        }
    });

but compareTo is not an Option, cannot resolve method.

Is x an int? If so, use Integer.compare(x1, x2).

shmosel
– shmosel

2017-04-24 18:14:13 +00:00
Commented Apr 24, 2017 at 18:14 — shmosel
– shmosel, Commented Apr 24, 2017 at 18:14

Andreas · Accepted Answer · 2017-04-24 18:21:41Z

2

Since x from PointF is a float, use Float.compare(float f1, float f2):

return Float.compare(measureEvi.getmCoordenate().x, t1.getmCoordenate().x);

answered Apr 24, 2017 at 18:21

Andreas

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2 Comments

Jhonycage Over a year ago

Do you know if I use this to compare Integer, would it work in android < 4.4, I am getting the following observation: add @Requires API 4.4 KITKAT

Andreas Over a year ago

@Juanca If you look at the documentation for Integer.compare(int x, int y), you'll see "added in API level 19", and following that link shows that to be Android 4.4, so no.

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