org.springframework.data.mongodb.core.mapping

Class ShardKey

java.lang.Object

org.springframework.data.mongodb.core.mapping.ShardKey

public class ShardKey
extends Object

Value object representing an entities Shard Key used to distribute documents across a sharded MongoDB cluster.
Immutable shard keys indicates a fixed value that is not updated (see MongoDB Reference: Change a Document's Shard Key Value), which allows to skip server round trips in cases where a potential shard key change might have occurred.

Since:

3.0

Author:

Christoph Strobl, Mark Paluch

Method Summary

Modifier and Type	Method and Description
org.bson.Document	getDocument() Get the raw MongoDB representation of the ShardKey.
Collection<String>	getPropertyNames()
static ShardKey	hash(String... propertyNames) Create a new ShardingStrategy.RANGE shard key.
static ShardKey	immutable(ShardKey shardKey) Turn the given ShardKey into an immutable one.
boolean	isImmutable()
boolean	isSharded() Return whether the shard key represents a sharded key.
static ShardKey	none() ShardKey indicating no shard key has been defined.
static ShardKey	range(String... propertyNames) Create a new ShardingStrategy.RANGE shard key.
int	size()

Methods inherited from class java.lang.Object

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

Method Detail

size

public int size()

Returns:

the number of properties used to form the shard key.

getPropertyNames

public Collection<String> getPropertyNames()

Returns:

the unmodifiable collection of property names forming the shard key.

isImmutable

public boolean isImmutable()

Returns:

true if the shard key of an document does not change.

See Also:

MongoDB Reference: Change a Document's Shard Key Value

isSharded

public boolean isSharded()

Return whether the shard key represents a sharded key. Return false if the key is not sharded.

Returns:

true if the key is sharded; false otherwise.

getDocument

public org.bson.Document getDocument()

Get the raw MongoDB representation of the ShardKey.

Returns:

never null.

none

public static ShardKey none()

ShardKey indicating no shard key has been defined.

Returns:

NONE

range

public static ShardKey range(String... propertyNames)

Create a new ShardingStrategy.RANGE shard key.

Parameters:

propertyNames - must not be null.

Returns:

new instance of ShardKey.

hash

public static ShardKey hash(String... propertyNames)

Create a new ShardingStrategy.RANGE shard key.

Parameters:

propertyNames - must not be null.

Returns:

new instance of ShardKey.

immutable

public static ShardKey immutable(ShardKey shardKey)

Turn the given ShardKey into an immutable one.

Parameters:

shardKey - must not be null.

Returns:

new instance of ShardKey if the given shard key is not already immutable.