TransformingComparator.java

package org.apache.commons.collections4.comparators;

import java.io.Serializable;
import java.util.Comparator;

public class TransformingComparator<I, O> implements Comparator<I>, Serializable {
    private static final long serialVersionUID = 3456940356043606220L;
    private final Comparator<O> decorated;
    private final Transformer<? super I, ? extends O> transformer;

    public TransformingComparator(Transformer<? super I, ? extends O> transformer) {
        this(transformer, null);
    }

    public TransformingComparator(Transformer<? super I, ? extends O> transformer, Comparator<O> decorated) {
        this.decorated = decorated;
        this.transformer = transformer;
    }

    public int compare(I obj1, I obj2) {
        O value1 = this.transformer.transform(obj1);
        O value2 = this.transformer.transform(obj2);
        return this.decorated.compare(value1, value2);
    }

    public int hashCode() {
        byte total = 17;
        int total1 = total * 37 + (this.decorated == null?0:this.decorated.hashCode());
        total1 = total1 * 37 + (this.transformer == null?0:this.transformer.hashCode());
        return total1;
    }

    public boolean equals(Object object) {
        if(this == object) {
            return true;
        } else if(null == object) {
            return false;
        } else if(!object.getClass().equals(this.getClass())) {
            return false;
        } else {
            TransformingComparator comp = (TransformingComparator)object;
            return null == this.decorated?null == comp.decorated:(this.decorated.equals(comp.decorated) && null == this.transformer?null == comp.transformer:this.transformer.equals(comp.transformer));
        }
    }
}