Subversion Repositories bacoAlunos

package pt.estgp.estgweb.domain.views.utils;

import pt.estgp.estgweb.domain.Record;
import pt.estgp.estgweb.domain.views.ManagedIdentifierCollectionView;
import org.apache.log4j.Logger;

/**
 *
 * @author  User
 */
public class ManagedIdentifierCollectionComparator implements java.util.Comparator<ManagedIdentifierCollectionView>
{


    private static final 1.5.0/docs/api/java/util/logging/Logger.html">Logger logger = 1.5.0/docs/api/java/util/logging/Logger.html">Logger.getLogger(ManagedIdentifierCollectionComparator.class);

    private static ManagedIdentifierCollectionComparator instance = null;

    public static ManagedIdentifierCollectionComparator getInstance()
    {
        if(instance == null)
        {
            instance = new ManagedIdentifierCollectionComparator();
        }
        return instance;
    }

    /** Creates a new instance of LongComparator */
    private ManagedIdentifierCollectionComparator() {
    }

    /** Compares its two arguments for order.  Returns a negative integer,
     * zero, or a positive integer as the first argument is less than, equal
     * to, or greater than the second.<p>
     *
     * The implementor must ensure that <tt>sgn(compare(x, y)) ==
     * -sgn(compare(y, x))</tt> for all <tt>x</tt> and <tt>y</tt>.  (This
     * implies that <tt>compare(x, y)</tt> must throw an exception if and only
     * if <tt>compare(y, x)</tt> throws an exception.)<p>
     *
     * The implementor must also ensure that the relation is transitive:
     * <tt>((compare(x, y)&gt;0) &amp;&amp; (compare(y, z)&gt;0))</tt> implies
     * <tt>compare(x, z)&gt;0</tt>.<p>
     *
     * Finally, the implementer must ensure that <tt>compare(x, y)==0</tt>
     * implies that <tt>sgn(compare(x, z))==sgn(compare(y, z))</tt> for all
     * <tt>z</tt>.<p>
     *
     * It is generally the case, but <i>not</i> strictly required that
     * <tt>(compare(x, y)==0) == (x.equals(y))</tt>.  Generally speaking,
     * any comparator that violates this condition should clearly indicate
     * this fact.  The recommended language is "Note: this comparator
     * imposes orderings that are inconsistent with equals."
     *
     * @param s1 the first object to be compared.
     * @param s2 the second object to be compared.
     * @return a negative integer, zero, or a positive integer as the
     *         first argument is less than, equal to, or greater than the
     *         second.
     * @throws ClassCastException if the arguments' types prevent them from
     *         being compared by this Comparator.
     *
     */
    public int compare(ManagedIdentifierCollectionView s1, ManagedIdentifierCollectionView s2)
    {
        if(s1.getName() == null)
        {
            return -1;
        }
        if(s2.getName() == null)
        {
            return -1;
        }
        int compareResult = s2.getName().compareTo(s1.getName());
        if(compareResult > 0)
            return 1;
        else if(compareResult < 0)
            return -1;
        return 0;
    }
}