org.goda.time

Class DateTimeComparator

java.lang.Object

org.goda.time.DateTimeComparator

All Implemented Interfaces:

Serializable, Comparator

public class DateTimeComparator
extends Object
implements Comparator, Serializable

DateTimeComparator provides comparators to compare one date with another.

Dates may be specified using any object recognised by the ConverterManager class.

The default objects recognised by the comparator are:

• ReadableInstant
• String
• Calendar
• Date
• Long (milliseconds)
• null (now)

DateTimeComparator is thread-safe and immutable.

Since:

1.0

Author:

Guy Allard, Stephen Colebourne, Brian S O'Neill

See Also:

Serialized Form

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	DateTimeComparator(DateTimeFieldType lowerLimit, DateTimeFieldType upperLimit) Restricted constructor.

Method Summary

Methods

Modifier and Type	Method and Description
int	compare(Object lhsObj, Object rhsObj) Compare two objects against only the range of date time fields as specified in the constructor.
boolean	equals(Object object) Compares this comparator to another.
static DateTimeComparator	getDateOnlyInstance() Returns a comparator that only considers date fields.
static DateTimeComparator	getInstance() Returns a DateTimeComparator the compares the entire date time value.
static DateTimeComparator	getInstance(DateTimeFieldType lowerLimit) Returns a DateTimeComparator with a lower limit only.
static DateTimeComparator	getInstance(DateTimeFieldType lowerLimit, DateTimeFieldType upperLimit) Returns a DateTimeComparator with a lower and upper limit.
DateTimeFieldType	getLowerLimit() Gets the field type that represents the lower limit of comparison.
static DateTimeComparator	getTimeOnlyInstance() Returns a comparator that only considers time fields.
DateTimeFieldType	getUpperLimit() Gets the field type that represents the upper limit of comparison.
int	hashCode() Gets a suitable hashcode.
String	toString() Gets a debugging string.

Methods inherited from class java.lang.Object

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

Constructor Detail

DateTimeComparator

protected DateTimeComparator(DateTimeFieldType lowerLimit,
                  DateTimeFieldType upperLimit)

Restricted constructor.

Parameters:

lowerLimit - the lower field limit, null means no limit

upperLimit - the upper field limit, null means no limit

Method Detail

getInstance

public static DateTimeComparator getInstance()

Returns a DateTimeComparator the compares the entire date time value.

Returns:

a comparator over all fields

getInstance

public static DateTimeComparator getInstance(DateTimeFieldType lowerLimit)

Returns a DateTimeComparator with a lower limit only. Fields of a magnitude less than the lower limit are excluded from comparisons.

Parameters:

lowerLimit - inclusive lower limit for fields to be compared, null means no limit

Returns:

a comparator over all fields above the lower limit

getInstance

public static DateTimeComparator getInstance(DateTimeFieldType lowerLimit,
                             DateTimeFieldType upperLimit)

Returns a DateTimeComparator with a lower and upper limit. Fields of a magnitude less than the lower limit are excluded from comparisons. Fields of a magnitude greater than or equal to the upper limit are also excluded from comparisons. Either limit may be specified as null, which indicates an unbounded limit.

Parameters:

lowerLimit - inclusive lower limit for fields to be compared, null means no limit

upperLimit - exclusive upper limit for fields to be compared, null means no limit

Returns:

a comparator over all fields between the limits

getDateOnlyInstance

public static DateTimeComparator getDateOnlyInstance()

Returns a comparator that only considers date fields. Time of day is ignored.

Returns:

a comparator over all date fields

getTimeOnlyInstance

public static DateTimeComparator getTimeOnlyInstance()

Returns a comparator that only considers time fields. Date is ignored.

Returns:

a comparator over all time fields

getLowerLimit

public DateTimeFieldType getLowerLimit()

Gets the field type that represents the lower limit of comparison.

Returns:

the field type, null if no upper limit

getUpperLimit

public DateTimeFieldType getUpperLimit()

Gets the field type that represents the upper limit of comparison.

Returns:

the field type, null if no upper limit

compare

public int compare(Object lhsObj,
          Object rhsObj)

Compare two objects against only the range of date time fields as specified in the constructor.

Specified by:

compare in interface Comparator

Parameters:

lhsObj - the first object, logically on the left of a < comparison, null means now

rhsObj - the second object, logically on the right of a < comparison, null means now

Returns:

zero if order does not matter, negative value if lhsObj < rhsObj, positive value otherwise.

Throws:

IllegalArgumentException - if either argument is not supported

equals

public boolean equals(Object object)

Compares this comparator to another.

Specified by:

equals in interface Comparator

Overrides:

equals in class Object

Parameters:

object - the object to compare to

Returns:

true if equal

hashCode

public int hashCode()

Gets a suitable hashcode.

Overrides:

hashCode in class Object

Returns:

the hashcode

toString

public String toString()

Gets a debugging string.

Overrides:

toString in class Object

Returns:

a debugging string