org.geotools.process.vector

Class TransformProcess

Object

TransformProcess

All Implemented Interfaces:

VectorProcess

public class TransformProcess
extends Object
implements VectorProcess

Used to transform a feature collection as defined using a series of expressions.

The definition of the output feature type can be provided as a TransformProcess.Definition data structure or using a simple string format:

 the_geom=the_geom
 name=name
 area=area( the_geom )
 

Attribute definitions can be delimited by line breaks and/or by semicolons.

This is a very flexible process which can be used to:

• Change the order of attributes - resulting in a new feature type:

   INPUT Schema          DEFINITION                     OUTPUT Schema
   the_geom: Polygon     the_geom                       the_geom: Polygon
   name: String          id                             id: Long
   id: Long              name                           name: String
   description: String   description                    description: String
   

• Rename or remove attributes - resulting in a new feature type:

   INPUT Schema          DEFINITION                     OUTPUT Schema
   the_geom: Polygon     the_geom                       the_geom: Polygon
   name: String          id_code=id                     id_code: Long
   id: Long              summary=description            summary: String
   description: String
   

• Process geometry - using functions like "the_geom=simplify( the_geom, 2.0 )" or "the_geom=centriod( the_geom )":

   INPUT Schema          DEFINITION                     OUTPUT Schema
   the_geom: Polygon     the_geom=centriod(the_geom)    the_geom: Point
   name: String          name                           name: String
   id: Long              id                             id: Long
   description: String   description                    description: String
   

• Generate additional attributes using the form: area=area( the_geom ):

   INPUT Schema          DEFINITION                     OUTPUT Schema
   the_geom: Polygon     the_geom=centriod(the_geom)    the_geom: Point
   name: String          name                           name: String
   id: Long              id                             id: Long
   description: String   description                    description: String
                         area=area( the_geom)           area: Double
                         text=concatenate(name,'-',id)  text: String
   

This is a port of the uDig "reshape" operation to the GeoTools process framework.

Author:

Jody Garnett (LISAsoft)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	TransformProcess.Definition Definition of an attribute used during transform Note this definition is terse as we are gathering the details from the origional FeatureType.

Constructor Summary

Constructors

Constructor and Description
TransformProcess()

Method Summary

Modifier and Type	Method and Description
SimpleFeatureCollection	execute(SimpleFeatureCollection features, String transform)
SimpleFeatureCollection	executeList(SimpleFeatureCollection features, List<TransformProcess.Definition> transform)
static List<TransformProcess.Definition>	toDefinition(String definition) Parse out a list of TransformProcess.Definition from the provided text description.
static SimpleFeatureType	toReShapeFeatureType(SimpleFeatureCollection delegate, List<TransformProcess.Definition> definitionList)

Methods inherited from class Object

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

Constructor Detail

TransformProcess

public TransformProcess()

Method Detail

execute

public SimpleFeatureCollection execute(SimpleFeatureCollection features,
                                       String transform)
                                throws ProcessException

Throws:

ProcessException

executeList

public SimpleFeatureCollection executeList(SimpleFeatureCollection features,
                                           List<TransformProcess.Definition> transform)
                                    throws ProcessException

Throws:

ProcessException

toDefinition

public static List<TransformProcess.Definition> toDefinition(String definition)

Parse out a list of TransformProcess.Definition from the provided text description.

The format expected here is one definition per line; using the format "name=...expression..".

Returns:

List of definition

toReShapeFeatureType

public static SimpleFeatureType toReShapeFeatureType(SimpleFeatureCollection delegate,
                                                     List<TransformProcess.Definition> definitionList)