com.goldencode.p2j.persist

Class BasicSorter<T extends java.lang.Comparable>

java.lang.Object

com.goldencode.p2j.persist.BasicSorter<T>

Type Parameters:

T - A type which extends/implements Comparable

All Implemented Interfaces:

java.io.Serializable, java.util.Comparator<T>

Direct Known Subclasses:

DataSorter

public class BasicSorter<T extends java.lang.Comparable>
extends java.lang.Object
implements java.util.Comparator<T>, java.io.Serializable

An implementation of Comparator, used to sort instances of Comparables in ascending or descending order. Direction of the sort is specified upon construction.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
private int	direction Multiplier used to adjust (possibly invert) sorting

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	BasicSorter(boolean ascending) Constructor which stores the sort direction.

Method Summary

Modifier and Type	Method and Description
int	compare(T d1, T d2) Compare two Comparable instances to determine relative sort order.
boolean	equals(java.lang.Object o) Test for equality between this comparator and another.
protected int	getDirection() Report the direction in which this sorter sorts its data.
int	hashCode() Calculate a hash code for this object.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.Comparator

comparing, comparing, comparingDouble, comparingInt, comparingLong, naturalOrder, nullsFirst, nullsLast, reversed, reverseOrder, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Field Detail

direction

private final int direction

Multiplier used to adjust (possibly invert) sorting

Constructor Detail

BasicSorter

protected BasicSorter(boolean ascending)

Constructor which stores the sort direction.

Parameters:

ascending - true if sort should be ascending; false if it should be descending.

Method Detail

compare

public int compare(T d1,
                   T d2)

Compare two Comparable instances to determine relative sort order. The comparison uses the natural order of the objects, except that unknown value always sorts high in an ascending sort. The result is inverted for descending sorts (meaning unknown value sorts low in a descending sort.

Specified by:

compare in interface java.util.Comparator<T extends java.lang.Comparable>

Parameters:

d1 - First value to compare. Must not be null.

d2 - Second value to compare. Must not be null.

Returns:

Positive value if d1 > d2; negative value if d1 < d2; 0 if d1 and d2 sort equivalently.

hashCode

public int hashCode()

Calculate a hash code for this object.

Overrides:

hashCode in class java.lang.Object

Returns:

Hash code.

equals

public boolean equals(java.lang.Object o)

Test for equality between this comparator and another. Equality means either both comparators represent the same object instance in memory, or that both comparators are instances of this class and sort in the same direction.

Specified by:

equals in interface java.util.Comparator<T extends java.lang.Comparable>

Overrides:

equals in class java.lang.Object

Returns:

true if objects are equal, else false.

getDirection

protected int getDirection()

Report the direction in which this sorter sorts its data.

Returns:

1 if ascending or -1 if descending.