Package net.sf.eBusx.time

Class EInterval

java.lang.Object

net.sf.eBus.messages.EMessageObject

net.sf.eBus.messages.EField

net.sf.eBusx.time.EInterval

All Implemented Interfaces:

java.io.Serializable

public final class EInterval
extends EField

Implements a time interval from one Instant to another. EInterval guarantees that begin time is ≤ end time. Each end point may be separately configured to be inclusive or exclusive. If begin time equals end time then both ends must be marked as inclusive.

EInterval extends EField so that it can be used in an eBus message. This means that EInterval.Builder must be used to create an EInterval instance.

EInterval is immutable and thread-safe.

Allen's Interval Algebra

Allen's temporal reasoning calculus is based on 13 base relations. Since 12 of these relations are simply inverses of each other (for example the inverse of x precedes y is y is preceded by x) only 7 relations are implemented in EInterval which are:

1. : interval 1 precedes interval 2 if interval 1 end time < interval 2 begin time.
2. : interval 1 meets interval 2 if if interval 1 end time equals interval 2 begin time.
3. : interval 1 overlaps interval 2 if interval 1 begin time < interval 2 begin time and interval 1 end time < interval 2 end time.
4. : interval 1 contains interval 2 if interval 1 begin time < interval 2 begin time and interval 1 end time > interval 2 end time.
5. : interval 1 starts interval 2 if interval 1 begin time equals interval 2 begin time and interval 1 end time < interval 2 end time.
6. : interval 1 finishes interval 2 if interval 1 begin time > interval 2 begin time and interval 1 end time equals interval 2 end time.
7. : interval 1 begin and end times equal interval 2 begin and end times.

Note: interval algebra methods below are based solely on the end point times and do not take clusivity into account.

Author:

Charles W. Rapp

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	EInterval.Builder	EInterval instances may be created only by using a Builder instance.
static class	EInterval.Clusivity	Specifies whether an end point is inclusive or exclusive.

Field Summary

Fields

Modifier and Type	Field	Description
EInterval.Clusivity	beginClusivity	Interval begin time clusivity.
java.time.Instant	beginTime	Interval begin time.
EInterval.Clusivity	endClusivity	Interval end time clusivity.
java.time.Instant	endTime	Interval end time.

Method Summary

Modifier and Type	Method	Description
static EInterval.Builder	builder()	Returns a new EInterval builder instance which is used to create an EInterval object.
boolean	contains(EInterval interval)	: Returns true if: this EInterval begin time < interval begin time and this EInterval end time > interval end time.
boolean	equals(java.lang.Object o)	: Returns true if: o is the same EInterval instance as this interval or o is a non-null EInterval instance with the same end points and clusivities as this EInterval instance.
boolean	finishes(EInterval interval)	: Returns true if this interval starts after intervaL buts ends at the same time.
int	hashCode()	Returns hash code based on end point times and clusivities.
boolean	meets(EInterval interval)	: Returns true if this EInterval end time equals interval begin time.
boolean	overlaps(EInterval interval)	: Returns true if: this EInterval end time is > interval's begin time, this EInterval end time is < interval's end time, and this EInterval begin time is < interval's begin time.
boolean	precedes(EInterval interval)	: Returns true if this EInterval end time is < interval begin time.
boolean	starts(EInterval interval)	: Returns true if this interval starts at the same time as interval but ends before.
java.lang.String	toString()	Returns textual representation of end point times and clusivities.

Methods inherited from class java.lang.Object

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

Field Detail

beginTime

public final java.time.Instant beginTime

Interval begin time.

beginClusivity

public final EInterval.Clusivity beginClusivity

Interval begin time clusivity.

endTime

public final java.time.Instant endTime

Interval end time.

endClusivity

public final EInterval.Clusivity endClusivity

Interval end time clusivity.

Method Detail

toString

public java.lang.String toString()

Returns textual representation of end point times and clusivities. Uses default Instant time format.

Overrides:

toString in class java.lang.Object

Returns:

interval as text.

equals

public boolean equals(java.lang.Object o)

: Returns true if:

• o is the same EInterval instance as this interval or
• o is a non-null EInterval instance with the same end points and clusivities as this EInterval instance.

Otherwise returns false.

Overrides:

equals in class java.lang.Object

Parameters:

o - comparison object.

Returns:

true if o is a non-null EInterval instance whose end points are equal and have the same clusivities.

hashCode

public int hashCode()

Returns hash code based on end point times and clusivities.

Overrides:

hashCode in class java.lang.Object

Returns:

hash code based on end point times and clusivities.

precedes

public boolean precedes(EInterval interval)

: Returns true if this EInterval end time is < interval begin time.

Note that this comparison is based only on time and does not take clusivity into account.

Parameters:

interval - comparison time interval.

Returns:

true if this EInterval precedes interval and false otherwise.

meets

public boolean meets(EInterval interval)

: Returns true if this EInterval end time equals interval begin time.

Note that this comparison is based only on time and does not take clusivity into account.

Parameters:

interval - comparison time interval.

Returns:

true if this EInterval meets interval and false otherwise.

overlaps

public boolean overlaps(EInterval interval)

: Returns true if:

• this EInterval end time is > interval's begin time,
• this EInterval end time is < interval's end time, and
• this EInterval begin time is < interval's begin time.

Note that this comparison is based only on time and does not take clusivity into account.

Parameters:

interval - comparison time interval.

Returns:

true if this EInterval overlaps interval and false otherwise.

contains

public boolean contains(EInterval interval)

: Returns true if:

• this EInterval begin time < interval begin time and
• this EInterval end time > interval end time.

In short, this interval contains the given argument interval.

Note that this comparison is based only on time and does not take clusivity into account.

Parameters:

interval - comparison time interval.

Returns:

true if this interval begins before interval and ends after.

starts

public boolean starts(EInterval interval)

: Returns true if this interval starts at the same time as interval but ends before. That is:

• this EInterval begin time equals interval begin time and
• this EInterval end time < interval end time.

Note that this comparison is based only on time and does not take clusivity into account.

Parameters:

interval - comparison time interval.

Returns:

true if this interval starts at the same time as interval but ends before.

finishes

public boolean finishes(EInterval interval)

: Returns true if this interval starts after intervaL buts ends at the same time. That is:

• this EInterval begin time > interval begin time and
• this EInterval end time equals interval end time.

Note that this comparison is based only on time and does not take clusivity into account.

Parameters:

interval - comparison time interval.

Returns:

true if this interval starts after intervaL buts ends at the same time.

builder

public static EInterval.Builder builder()

Returns a new EInterval builder instance which is used to create an EInterval object. It is recommended that a new builder be used when creating an EInterval instance and not re-use a Builder to create multiple intervals.

Returns:

interval builder instance.