SpatialJavaDStream (Oracle Big Data Spatial and Graph Vector Analysis Java API Reference)

java.lang.Object
- <any>
- - oracle.spatial.spark.vector.streaming.dstream.SpatialJavaDStream<T>

Type Parameters:

T -
```
public class SpatialJavaDStream<T>
extends <any>
```
This class represents a spatially enabled DStream. A SpatialJavaDStream encapsulates an existing DStream and adds spatial transformations and functions.

Spatial information is extracted from the source DStream using an implementation of SparkRecordInfoProvider provided by the user just like it is done with SpatialJavaRDD. The SparkRecordInfoProvider is expected to return the geometry of spatial records.

The following example shows how to create a SpatialJavaDStream from a text DStream, using a SparkRecordInfo which extracts the spatial information from text records
```
 
 JavaDStream<String> textStream = ssc.socketTextStream(host, port)
 SparkRecordInfoProvider recordInfoProvider = new CSVRecordInfoProvider();
 SpatialJavaDStream<String> spatialStream = SpatialJavaDStream.fromJavaDStream(textStream, recordInfoProvider, String.class);
 
 
```
The previous example creates a SpatialJavaDStream which records are of type String as the source DStream. Every time a spatial operation is performed, the provided SparkRecordInfoProvider instance will be used to extract the spatial information. For some data set formats, like JSON, extracting spatial information may require parsing each record every time the spatial information is needed for a spatial operation and it may be executed several times if multiple spatial transformations are applied.

A way to ensure records will be parsed only once by the SparkRecordInfoProvider is to create a SpatialJavaDStream which records are of type SparkRecordInfo. A SparkRecordInfo holds spatial information and any desired additional data from the source stream records. The SpatialJavaDStream static method SpatialJavaRDD#fromJavaDStream(JavaDStream, SparkRecordInfoProvider) can be used to create JavaSpatialDStream of type SparkRecordInfo.

Spatial versions of existing transformations are provided. Spatial transformations take the following parameters:
- A lambda provided by the user to further filter or transform records. This is the same lambda function passed to the non-spatial version of the transformation
- An instance of SpatialOperationConfig which contains the information of the spatial operation to be performed to filter records.
Author:

hsaucedo

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`SpatialTransformationContext<T>`	`createSpatialTransformationContext()` Creates an instance of `SpatialTransformationContext`
`SpatialTransformationContext<T>`	`createSpatialTransformationContext(SpatialOperationConfig spatialOperationConf)` Creates an instance of `SpatialTransformationContext` associated to the given `SpatialOperationConfig`.
`<R> <any>`	`enrich(<any> f, GeoEnricher enricher)` Finds features related to the geometries of the stream´s records and uses a user-provided lambda to transform the enriched records
`SpatialJavaDStream<T>`	`filter(<any> f, SpatialOperationConfig spatialOpConf)` Performs a filter transformation.
`<U> <any>`	`flatMap(<any> f, SpatialOperationConfig spatialOpConf)` Returns a new DStream by first spatially filtering the stream elements using the spatial operation given by spatialOpConf, then a flattening function is applied to all the remaining elements.
`static <T> SpatialJavaDStream<T>`	`fromDStream(<any> src, SparkRecordInfoProvider<T> recordInfoProvider)` Creates a spatial JavaDStream from an existing DStream
`static <T> SpatialJavaDStream<SparkRecordInfo>`	`fromJavaDStream(<any> src, SparkRecordInfoProvider<T> recordInfoProvider)` Creates a spatial JavaDStream which records are of type `SparkRecordInfo`
`static <T> SpatialJavaDStream<T>`	`fromJavaDStream(<any> src, SparkRecordInfoProvider<T> recordInfoProvider, java.lang.Class<T> type)` Creates a spatial JavaDStream from an existing JavaDStream
`SparkRecordInfoProvider<T>`	`getRecordInfoProvider()` Returns the current stream's `SparkRecordInfoProvider` instance
`java.lang.Class<T>`	`getType()` Returns the type of the records in this stream
`<any>`	`nearestNeighbors(<any> f, int k, SpatialOperationConfig spatialOpConf)` Returns a DStream containing one single element with the k elements which are closest to the given query window
`StreamingContext`	`ssc()` Returns the underlying StreamingContext

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - createSpatialTransformationContext
```
public SpatialTransformationContext<T> createSpatialTransformationContext()
```
    Creates an instance of SpatialTransformationContext
    
    Returns:
    
    an instance of SpatialTransformationContext
  - createSpatialTransformationContext
```
public SpatialTransformationContext<T> createSpatialTransformationContext(SpatialOperationConfig spatialOperationConf)
```
    Creates an instance of SpatialTransformationContext associated to the given SpatialOperationConfig.
    
    Parameters:
    
    spatialOperationConf - a spatial operation used to filter records
    
    Returns:
    
    an instance of SpatialTransformationContext
  - enrich
```
public <R> <any> enrich(<any> f,
                        GeoEnricher enricher)
```
    Finds features related to the geometries of the stream´s records and uses a user-provided lambda to transform the enriched records
    
    Parameters:
    
    f - a lambda which receives stream's records with their associated features
    
    enricher - a component used to associate a geometry from the stream's records to features from different spatial data layers
    
    ssc - the spark streaming context
    
    Returns:
    
    a new DStream containing results of the type defined by the lambda function
  - filter
```
public SpatialJavaDStream<T> filter(<any> f,
                                    SpatialOperationConfig spatialOpConf)
```
    Performs a filter transformation. Automatically filters records that match the given spatial criteria defined by an instance of SpatialOperationConfig.
    
    Parameters:
    
    f - lambda function to further filtering records
    
    spatialOpConf - spatial criteria used for spatial filtering
    
    Returns:
    
    a filtered spatial DStream
  - flatMap
```
public <U> <any> flatMap(<any> f,
                         SpatialOperationConfig spatialOpConf)
```
    Returns a new DStream by first spatially filtering the stream elements using the spatial operation given by spatialOpConf, then a flattening function is applied to all the remaining elements.
    
    Parameters:
    
    m - a function to apply to each element
    
    spatialOpConf - a spatial operation used to filter records
    
    Returns:
    
    a new DStream
  - fromDStream
```
public static <T> SpatialJavaDStream<T> fromDStream(<any> src,
                                                    SparkRecordInfoProvider<T> recordInfoProvider)
```
    Creates a spatial JavaDStream from an existing DStream
    
    Parameters:
    
    src - the source stream
    
    recordInfoProvider - an instance of SparkRecordInfoProvider used to extract spatial information from the stream´s records
    
    Returns:
    
    a new spatial DStream
  - fromJavaDStream
```
public static <T> SpatialJavaDStream<SparkRecordInfo> fromJavaDStream(<any> src,
                                                                      SparkRecordInfoProvider<T> recordInfoProvider)
```
    Creates a spatial JavaDStream which records are of type SparkRecordInfo
    
    Parameters:
    
    src - the source stream
    
    recordInfoProvider - an instance of SparkRecordInfoProvider used to extract spatial information from the stream´s records
    
    Returns:
    
    a new spatial DStream containing records of type SparkRecordInfo
  - fromJavaDStream
```
public static <T> SpatialJavaDStream<T> fromJavaDStream(<any> src,
                                                        SparkRecordInfoProvider<T> recordInfoProvider,
                                                        java.lang.Class<T> type)
```
    Creates a spatial JavaDStream from an existing JavaDStream
    
    Parameters:
    
    src - the source stream
    
    recordInfoProvider - an instance of SparkRecordInfoProvider used to extract spatial information from the stream´s records
    
    type - the type of the spatial stream´s records
    
    Returns:
    
    a new spatial DStream
  - getRecordInfoProvider
```
public SparkRecordInfoProvider<T> getRecordInfoProvider()
```
    Returns the current stream's SparkRecordInfoProvider instance
    
    Returns:
  - getType
```
public java.lang.Class<T> getType()
```
    Returns the type of the records in this stream
    
    Returns:
  - nearestNeighbors
```
public <any> nearestNeighbors(<any> f,
                              int k,
                              SpatialOperationConfig spatialOpConf)
```
    Returns a DStream containing one single element with the k elements which are closest to the given query window
    
    Parameters:
    
    qryWindow - a geometry from where the nearest neighbors will be calculated
    
    k - the number of neighbors
    
    tol - the tolerance used
    
    Returns:
    
    a DStream containing one list with the k nearest neighbors sorted by distance
  - ssc
```
public StreamingContext ssc()
```
    Returns the underlying StreamingContext
    
    Returns:

Class SpatialJavaDStream<T>

Method Summary

Methods inherited from class java.lang.Object

Method Detail

createSpatialTransformationContext

createSpatialTransformationContext

enrich

filter

flatMap

fromDStream

fromJavaDStream

fromJavaDStream

getRecordInfoProvider

getType

nearestNeighbors

ssc