Package oracle.kv

Class KeyRange

java.lang.Object

oracle.kv.KeyRange

All Implemented Interfaces:

oracle.kv.impl.util.FastExternalizable

public class KeyRange
extends Object
implements oracle.kv.impl.util.FastExternalizable

Defines a range of Key components for use in multiple-key operations and iterations.

The KeyRange defines a range of String values for the key components immediately following the last component of a parent key that is used in a multiple-key operation. In terms of a tree structure, the range defines the parent key's immediate children that are selected by the multiple-key operation.

Constructor Summary

Constructors

Constructor	Description
KeyRange(String prefix)	Creates a prefix KeyRange.
KeyRange(String start, boolean startInclusive, String end, boolean endInclusive)	Creates a start/end KeyRange.

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object other)
static KeyRange	fromByteArray(byte[] keyBytes)	Deserializes the given bytes that were returned earlier by toByteArray() and returns the resulting KeyRange.
static KeyRange	fromString(String keyRangeStringArg)	Converts an encoded KeyRange back to a KeyRange.
String	getEnd()	Returns the String component that defines upper bound of the key range, or null if no upper bound is enforced.
boolean	getEndInclusive()	Returns whether end is included in the range, i.e., end is greater than or equal to the last String component in the key range.
String	getStart()	Returns the String component that defines lower bound of the key range, or null if no lower bound is enforced.
boolean	getStartInclusive()	Returns whether start is included in the range, i.e., start is less than or equal to the first String component in the key range.
int	hashCode()
boolean	inRange(Key parentKey, Key checkKey)	Returns true if a Key is within the bounds of this range with respect to a parent Key.
boolean	isPrefix()	Returns whether this is a prefix range, i.e., whether start and end are equal and both inclusive.
byte[]	toByteArray()	Returns this KeyRange as a serialized byte array, such that fromByteArray(byte[]) may be used to reconstitute the KeyRange.
String	toString()	Encodes the KeyRange object and returns the resulting String which can later be decoded using fromString(java.lang.String).

Methods inherited from class java.lang.Object

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

Methods inherited from interface oracle.kv.impl.util.FastExternalizable

deserializedForm

Constructor Details

KeyRange

public KeyRange(String start,
 boolean startInclusive,
 String end,
 boolean endInclusive)

Creates a start/end KeyRange.

Parameters:

start - is the String component that defines lower bound of the key range. If null, no lower bound is enforced.

startInclusive - is true if start is included in the range, i.e., start is less than or equal to the first String component in the key range.

end - is the String component that defines upper bound of the key range. If null, no upper bound is enforced.

endInclusive - is true if end is included in the range, i.e., end is greater than or equal to the last String component in the key range.

Throws:

IllegalArgumentException - if either start and end are null or start is not less than end.

KeyRange

public KeyRange(String prefix)

Creates a prefix KeyRange.

For a KeyRange created using this constructor, isPrefix() will return true.

Additionally, both getStart() and getEnd() will return the prefix, and both getStartInclusive() and getEndInclusive() will return true. However, the KeyRange will be treated as a prefix, not an inclusive range.

Parameters:

prefix - is the value that is a prefix of all matching key components. The KeyRange matches a key component if the component starts with (as in String.startsWith) the prefix value.

Method Details

toByteArray

public byte[] toByteArray()

Returns this KeyRange as a serialized byte array, such that fromByteArray(byte[]) may be used to reconstitute the KeyRange. Values returned by calls to this method can be used with current and newer releases, but are not guaranteed to be compatible with earlier releases.

fromByteArray

public static KeyRange fromByteArray(byte[] keyBytes)

Deserializes the given bytes that were returned earlier by toByteArray() and returns the resulting KeyRange. Values created with either the current or earlier releases can be used with this method, but values created by later releases are not guaranteed to be compatible.

getStart

public String getStart()

Returns the String component that defines lower bound of the key range, or null if no lower bound is enforced. For a prefix range, this method returns the prefix.

getStartInclusive

public boolean getStartInclusive()

Returns whether start is included in the range, i.e., start is less than or equal to the first String component in the key range. For a prefix range, this method returns true.

getEnd

public String getEnd()

Returns the String component that defines upper bound of the key range, or null if no upper bound is enforced. For a prefix range, this method returns the prefix.

getEndInclusive

public boolean getEndInclusive()

Returns whether end is included in the range, i.e., end is greater than or equal to the last String component in the key range. For a prefix range, this method returns true.

isPrefix

public boolean isPrefix()

Returns whether this is a prefix range, i.e., whether start and end are equal and both inclusive.

inRange

public boolean inRange(Key parentKey,
 Key checkKey)

Returns true if a Key is within the bounds of this range with respect to a parent Key.

Parameters:

parentKey - the parent of the key range, or null to check the first key component.

checkKey - the full key being checked.

Returns:

true if it's in range, false otherwise.

equals

public boolean equals(Object other)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Encodes the KeyRange object and returns the resulting String which can later be decoded using fromString(java.lang.String). The format is:

<startType>/<start>/<end>/<endType>

where the startType/endType is either "I" or "E" for Inclusive or Exclusive and start and end are the start/end key strings. The leading startType/start specification is omitted from the String representation if the range does not have a lower bound. Similarly, the trailing end/endType specification is omitted if the range does not have an upper bound. Since a KeyRange requires at least one bound, at least one of the specifications is always present in the String representation. Here are some examples:

1. I/alpha/beta/E - from alpha inclusive to beta exclusive
2. E//0123/I - from "" exclusive to 0123 inclusive
3. I/chi/ - from chi inclusive to infinity
4. E//- from "" exclusive to infinity
5. /chi/E - from negative infinity to chi exclusive
6. //I - from negative infinity to "" inclusive

Overrides:

toString in class Object

fromString

public static KeyRange fromString(String keyRangeStringArg)

Converts an encoded KeyRange back to a KeyRange. The argument String should normally be created using toString(). See toString() for more information about the KeyRange String format.

Parameters:

keyRangeStringArg - a non null KeyRange encoding string, which should normally be created using toString().

Returns:

the resulting KeyRange object.

Throws:

IllegalArgumentException - if keyRangeStringArg does not contain a valid KeyRange encoding.

Since:

2.0