org.geotools.data.sort

Class SortedFeatureReader

Object

SortedFeatureReader

All Implemented Interfaces:

Closeable, AutoCloseable, FeatureReader<SimpleFeatureType,SimpleFeature>, SimpleFeatureReader

public class SortedFeatureReader
extends Object
implements SimpleFeatureReader

FeatureReader used to sort contents.

The implementation makes use of {@link MergeSortDumper).

Constructor Summary

Constructors

Constructor and Description
SortedFeatureReader(SimpleFeatureReader reader, Query query) Builds a new sorting feature reader
SortedFeatureReader(SimpleFeatureReader reader, SortBy[] sortBy, int maxFeatures) Builds a new sorting feature reader

Method Summary

Modifier and Type	Method and Description
static boolean	canSort(SimpleFeatureType schema, SortBy... sortBy) Checks if the schema and the sortBy are suitable for merge/sort.
void	close() Release the underlying resources associated with this stream.
static Comparator<SimpleFeature>	getComparator(SortBy... sortBy) Builds a comparator that can be used to sort SimpleFeature instances in memory
static Comparator<SimpleFeature>	getComparator(SortBy[] sortBy, SimpleFeatureType schema) Builds a comparator that can be used to sort SimpleFeature instances in memory
SimpleFeatureType	getFeatureType() Return the FeatureType this reader has been configured to create.
static int	getMaxFeaturesInMemory(Query q) Gets the max amount amount of features to keep in memory from the query and system hints
boolean	hasNext() Query whether this FeatureReader has another Feature.
SimpleFeature	next() Reads the next Feature in the FeatureReader.

Methods inherited from class Object

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

Constructor Detail

SortedFeatureReader

public SortedFeatureReader(SimpleFeatureReader reader,
                           Query query)
                    throws IOException

Builds a new sorting feature reader

Parameters:

reader - The reader to be sorted

query - The query holding the SortBy directives, and the eventual max features in memory hint Hints.MAX_MEMORY_SORT

Throws:

IOException

SortedFeatureReader

public SortedFeatureReader(SimpleFeatureReader reader,
                           SortBy[] sortBy,
                           int maxFeatures)
                    throws IOException

Builds a new sorting feature reader

Parameters:

reader - The reader to be sorted

sortBy - The sorting directives

maxFeatures - The maximum number of features to keep in memory

Throws:

IOException

Method Detail

canSort

public static final boolean canSort(SimpleFeatureType schema,
                                    SortBy... sortBy)

Checks if the schema and the sortBy are suitable for merge/sort. All attributes need to be Serializable, all sorting attributes need to be Comparable

getMaxFeaturesInMemory

public static int getMaxFeaturesInMemory(Query q)

Gets the max amount amount of features to keep in memory from the query and system hints

getFeatureType

public SimpleFeatureType getFeatureType()

Description copied from interface: FeatureReader

Return the FeatureType this reader has been configured to create.

Specified by:

getFeatureType in interface FeatureReader<SimpleFeatureType,SimpleFeature>

Returns:

the FeatureType of the Features this FeatureReader will create.

next

public SimpleFeature next()
                   throws IOException,
                          IllegalArgumentException,
                          NoSuchElementException

Description copied from interface: FeatureReader

Reads the next Feature in the FeatureReader.

Specified by:

next in interface FeatureReader<SimpleFeatureType,SimpleFeature>

Returns:

The next feature in the reader.

Throws:

IOException - If an error occurs reading the Feature.

NoSuchElementException - If there are no more Features in the Reader.

IllegalArgumentException

hasNext

public boolean hasNext()
                throws IOException

Description copied from interface: FeatureReader

Query whether this FeatureReader has another Feature.

Specified by:

hasNext in interface FeatureReader<SimpleFeatureType,SimpleFeature>

Returns:

True if there are more Features to be read. In other words, true if calls to next would return a feature rather than throwing an exception.

Throws:

IOException - If an error occurs determining if there are more Features.

close

public void close()
           throws IOException

Description copied from interface: FeatureReader

Release the underlying resources associated with this stream.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in interface FeatureReader<SimpleFeatureType,SimpleFeature>

Throws:

IOException - if an I/O error occurs

getComparator

public static Comparator<SimpleFeature> getComparator(SortBy... sortBy)

Builds a comparator that can be used to sort SimpleFeature instances in memory

getComparator

public static Comparator<SimpleFeature> getComparator(SortBy[] sortBy,
                                                      SimpleFeatureType schema)

Builds a comparator that can be used to sort SimpleFeature instances in memory