view flys-backend/src/main/java/de/intevation/flys/importer/ValueKey.java @ 4174:eaf83d4ae6b1

Sorted gauges for reference gauge selection in historical discharge calculation based on their name. Now, Gauge implements the Java Comparable interface and takes its name into account.
author Ingo Weinzierl <ingo.weinzierl@intevation.de>
date Thu, 18 Oct 2012 13:12:24 +0200
parents 6dc847194625
children
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package de.intevation.flys.importer;

import java.math.BigDecimal;

import java.util.Comparator;

public class ValueKey
{
    public static final double EPSILON = 1e-6;

    public static final Comparator<ValueKey> EPSILON_COMPARATOR =
        new Comparator<ValueKey>()
    {
        public int compare(ValueKey x, ValueKey y) {
            int cmp = ValueKey.compare(x.a, y.a);
            if (cmp != 0) return cmp;
            return ValueKey.compare(x.b, y.b);
        }
    };

    public static int compare(BigDecimal a, BigDecimal b) {
        if (a == null && b == null) return  0;
        if (a != null && b == null) return +1;
        if (a == null && b != null) return -1;

        double diff = a.doubleValue() - b.doubleValue();
        if (diff < -EPSILON) return -1;
        return diff > EPSILON ? +1 : 0;
    }

    protected BigDecimal a;
    protected BigDecimal b;

    public ValueKey() {
    }

    public ValueKey(BigDecimal a, BigDecimal b) {
        this.a = a;
        this.b = b;
    }

    @Override
    public int hashCode() {
        return ((a != null ? a.hashCode() : 0) << 16)
              | (b != null ? b.hashCode() : 0);
    }

    @Override
    public boolean equals(Object other) {
        if (!(other instanceof ValueKey)) {
            return false;
        }
        ValueKey o = (ValueKey)other;
        return !(
               (a == null && o.a != null)
            || (a != null && o.a == null)
            || (a != null && !a.equals(o.a))
            || (b == null && o.b != null)
            || (b != null && o.b == null)
            || (b != null && !b.equals(o.b)));
    }
}
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