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ObjectQueryCapabilities
public class QueryCapabilities
Describes the query capabilities for a specific FeatureType, so client code can request which features are natively supported by a FeatureSource.
This is the minimal Query capabilities we could come up in order to reliably support paging. Yet, the need for a more complete set of capabilities is well known and a new proposal should be done in order to define the complete set of capabilities a FeatureSource should advertise.
Constructor Summary | |
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QueryCapabilities()
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Method Summary | |
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boolean |
isJoiningSupported()
If true the datastore supports joins between feature types within the datastores. |
boolean |
isOffsetSupported()
Is offset supported. |
boolean |
isReliableFIDSupported()
Returns whether the feature source is capable of producing "reliable" fids. |
boolean |
isUseProvidedFIDSupported()
If true the datastore supports using the provided feature id in the data insertion workflow as opposed to generating a new id. |
boolean |
isVersionSupported()
If true the datastore supports version information and allows version based queries. |
boolean |
supportsSorting(SortBy[] sortAttributes)
Returns whether a list of properties can be used as SortBy keys. |
Methods inherited from class Object |
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clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Constructor Detail |
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public QueryCapabilities()
Method Detail |
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public boolean isOffsetSupported()
SortBy.NATURAL_ORDER
shall be supported, and be the default order if a Query
with offset but no SortBy is issued.
public boolean supportsSorting(SortBy[] sortAttributes)
May include current feature type properties as well as "@id"
for sorting on
the Feature ID. Note, however, that ability to sort by the fature id does not necessarily
implies the same ordering than SortBy.NATURAL_ORDER, though its probable they match for
datastores where the feature id is built up from a primary key.
Returns true if passed a null or empty array, otherwise the actual attributes are checked. When the array is not null and not empty, by default returns false. FeatureSource implementations should override as needed.
public boolean isReliableFIDSupported()
In this content the term "reliable" refers to the ability to read the same feature twice (with no transactions against the feature source in the interim) and get the same feature id back both times.
public boolean isUseProvidedFIDSupported()
Property.getUserData()
) for a Hints.USE_PROVIDED_FID
key associated to a
Boolean.TRUE
value, if the key/value pair is there an attempt to use the provided
id will be made, and the operation will fail of the key cannot be parsed into a valid
storage identifier.
public boolean isJoiningSupported()
public boolean isVersionSupported()
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