DATACMNS-651 - Introduced a Range value type.

Primarily intended to be used with Distance instances, we introduce a Range value type. Distance now has factory methods to create Range instances between two distances. To support this, Distance now implements comparable based on the normalized value of it.

Tiny refactoring in TypeDiscoverer to avoid code duplication between the lookup of parameter type information for constructors and methods.

src/main/java/org/springframework/data/geo/Distance.java

@@ -17,6 +17,7 @@ package org.springframework.data.geo;
 
 import java.io.Serializable;
 
+import org.springframework.data.domain.Range;
 import org.springframework.util.Assert;
 
 /**
@@ -26,7 +27,7 @@ import org.springframework.util.Assert;
  * @author Thomas Darimont
  * @since 1.8
  */
-public class Distance implements Serializable {
+public class Distance implements Serializable, Comparable<Distance> {
 
 	private static final long serialVersionUID = 2460886201934027744L;
 
@@ -54,6 +55,30 @@ public class Distance implements Serializable {
 		this.metric = metric == null ? Metrics.NEUTRAL : metric;
 	}
 
+	/**
+	 * Creates a {@link Range} between the given {@link Distance}.
+	 * 
+	 * @param min can be {@literal null}.
+	 * @param max can be {@literal null}.
+	 * @return will never be {@literal null}.
+	 */
+	public static Range<Distance> between(Distance min, Distance max) {
+		return new Range<Distance>(min, max);
+	}
+
+	/**
+	 * Creates a new {@link Range} by creating minimum and maximum {@link Distance} from the given values.
+	 * 
+	 * @param minValue
+	 * @param minMetric can be {@literal null}.
+	 * @param maxValue
+	 * @param maxMetric can be {@literal null}.
+	 * @return
+	 */
+	public static Range<Distance> between(double minValue, Metric minMetric, double maxValue, Metric maxMetric) {
+		return between(new Distance(minValue, minMetric), new Distance(maxValue, maxMetric));
+	}
+
 	/**
 	 * Returns the distance value in the current {@link Metric}.
 	 * 
@@ -138,6 +163,18 @@ public class Distance implements Serializable {
 		return this.metric.equals(metric) ? this : new Distance(getNormalizedValue() * metric.getMultiplier(), metric);
 	}
 
+	/* 
+	 * (non-Javadoc)
+	 * @see java.lang.Comparable#compareTo(java.lang.Object)
+	 */
+	@Override
+	public int compareTo(Distance o) {
+
+		double difference = this.getNormalizedValue() - o.getNormalizedValue();
+
+		return difference == 0 ? 0 : difference > 0 ? 1 : -1;
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see java.lang.Object#equals(java.lang.Object)