org.geotools.geojson.feature

Class FeatureJSON

Object

FeatureJSON

public class FeatureJSON
extends Object

Reads and writes feature objects to and from geojson.

 SimpleFeature feature = ...;

 FeatureJSON io = new FeatureJSON();
 io.writeFeature(feature, "feature.json"));

 Iterator features = io.streamFeatureCollection("features.json");
 while(features.hasNext()) {
   feature = features.next();
   ...
 }
 

Author:

Justin Deoliveira, OpenGeo

Constructor Summary

Constructors

Constructor and Description
FeatureJSON()
FeatureJSON(GeometryJSON gjson)

Method Summary

Modifier and Type	Method and Description
boolean	isEncodeFeatureBounds() The flag controlling whether feature bounds are encoded.
boolean	isEncodeFeatureCollectionBounds() The flag controlling whether feature collection bounds are encoded.
boolean	isEncodeFeatureCollectionCRS() The flag controlling whether feature collection coordinate reference systems are encoded.
boolean	isEncodeFeatureCRS() The flag controlling whether feature coordinate reference systems are encoded.
boolean	isEncodeNullValues() The flag controlling whether properties with null values are encoded.
CoordinateReferenceSystem	readCRS(InputStream input) Reads a coordinate reference system from GeoJSON.
CoordinateReferenceSystem	readCRS(Object input) Reads a coordinate reference system from GeoJSON.
SimpleFeature	readFeature(InputStream input) Reads a feature from GeoJSON.
SimpleFeature	readFeature(Object input) Reads a feature from GeoJSON.
FeatureCollection	readFeatureCollection(InputStream input) Reads a feature collection from GeoJSON.
FeatureCollection	readFeatureCollection(Object input) Reads a feature collection from GeoJSON.
SimpleFeatureType	readFeatureCollectionSchema(InputStream input, boolean nullValuesEncoded) Reads the SimpleFeatureType of a GeoJSON feature collection.
SimpleFeatureType	readFeatureCollectionSchema(Object input, boolean nullValuesEncoded) Reads the SimpleFeatureType of a GeoJSON feature collection.
void	setEncodeFeatureBounds(boolean encodeFeatureBounds) Sets the flag controlling whether feature bounds are encoded.
void	setEncodeFeatureCollectionBounds(boolean encodeFeatureCollectionBounds) Sets the flag controlling whether feature collection bounds are encoded.
void	setEncodeFeatureCollectionCRS(boolean encodeFeatureCollectionCRS) Sets the flag controlling whether feature collection coordinate reference systems are encoded.
void	setEncodeFeatureCRS(boolean encodeFeatureCRS) Sets the flag controlling whether feature coordinate reference systems are encoded.
void	setEncodeNullValues(boolean encodeNullValues) Sets the flag controlling whether properties with null values are encoded.
void	setFeatureType(SimpleFeatureType featureType) Sets the target feature type for parsing.
FeatureIterator<SimpleFeature>	streamFeatureCollection(Object input) Reads a feature collection from GeoJSON streaming back the contents via an iterator.
String	toString(CoordinateReferenceSystem crs) Writes a coordinate reference system as GeoJSON returning the result as a string.
String	toString(FeatureCollection features) Writes a feature collection as GeoJSON returning the result as a string.
String	toString(SimpleFeature feature) Writes a feature as GeoJSON returning the result as a string.
void	writeCRS(CoordinateReferenceSystem crs, Object output) Writes a coordinate reference system as GeoJSON.
void	writeCRS(CoordinateReferenceSystem crs, OutputStream output) Writes a coordinate reference system as GeoJSON.
void	writeFeature(SimpleFeature feature, Object output) Writes a feature as GeoJSON.
void	writeFeature(SimpleFeature feature, OutputStream output) Writes a feature as GeoJSON.
void	writeFeatureCollection(FeatureCollection features, Object output) Writes a feature collection as GeoJSON.
void	writeFeatureCollection(FeatureCollection features, OutputStream output) Writes a feature collection as GeoJSON.

Methods inherited from class Object

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

Constructor Detail

FeatureJSON

public FeatureJSON()

FeatureJSON

public FeatureJSON(GeometryJSON gjson)

Method Detail

setFeatureType

public void setFeatureType(SimpleFeatureType featureType)

Sets the target feature type for parsing.

Setting the target feature type will help the geojson parser determine the type of feature properties during properties. When the type is not around all properties are returned as a string.

Parameters:

featureType - The feature type. Parsed features will reference this feature type.

setEncodeFeatureBounds

public void setEncodeFeatureBounds(boolean encodeFeatureBounds)

Sets the flag controlling whether feature bounds are encoded.

See Also:

isEncodeFeatureBounds()

isEncodeFeatureBounds

public boolean isEncodeFeatureBounds()

The flag controlling whether feature bounds are encoded.

When set each feature object will contain a "bbox" attribute whose value is an array containing the elements of the bounding box (in x1,y1,x2,y2 order) of the feature

setEncodeFeatureCollectionBounds

public void setEncodeFeatureCollectionBounds(boolean encodeFeatureCollectionBounds)

Sets the flag controlling whether feature collection bounds are encoded.

See Also:

isEncodeFeatureCollectionBounds()

isEncodeFeatureCollectionBounds

public boolean isEncodeFeatureCollectionBounds()

The flag controlling whether feature collection bounds are encoded.

When set the feature collection object will contain a "bbox" attribute whose value is an array containing elements of the bounding box (in x1,y1,x2,y2 order) of the feature collection.

setEncodeFeatureCRS

public void setEncodeFeatureCRS(boolean encodeFeatureCRS)

Sets the flag controlling whether feature coordinate reference systems are encoded.

See Also:

isEncodeFeatureCRS()

isEncodeFeatureCRS

public boolean isEncodeFeatureCRS()

The flag controlling whether feature coordinate reference systems are encoded.

When set each feature object will contain a "crs" attribute describing the coordinate reference system of the feature.

setEncodeFeatureCollectionCRS

public void setEncodeFeatureCollectionCRS(boolean encodeFeatureCollectionCRS)

Sets the flag controlling whether feature collection coordinate reference systems are encoded.

See Also:

isEncodeFeatureCollectionCRS()

isEncodeFeatureCollectionCRS

public boolean isEncodeFeatureCollectionCRS()

The flag controlling whether feature collection coordinate reference systems are encoded.

When set the feature collection object will contain a "crs" attribute describing the coordinate reference system of the feature collection.

setEncodeNullValues

public void setEncodeNullValues(boolean encodeNullValues)

Sets the flag controlling whether properties with null values are encoded.

See Also:

isEncodeNullValues()

isEncodeNullValues

public boolean isEncodeNullValues()

The flag controlling whether properties with null values are encoded.

When set, properties with null values are encoded as null in the GeoJSON document.

writeFeature

public void writeFeature(SimpleFeature feature,
                         Object output)
                  throws IOException

Writes a feature as GeoJSON.

Parameters:

feature - The feature.

output - The output. See GeoJSONUtil.toWriter(Object) for details.

Throws:

IOException

writeFeature

public void writeFeature(SimpleFeature feature,
                         OutputStream output)
                  throws IOException

Writes a feature as GeoJSON.

This method calls through to #writeFeature(FeatureCollection, Object)

Parameters:

feature - The feature.

output - The output stream.

Throws:

IOException

toString

public String toString(SimpleFeature feature)
                throws IOException

Writes a feature as GeoJSON returning the result as a string.

Parameters:

feature - The feature

Returns:

The geometry encoded as GeoJSON

Throws:

IOException

readFeature

public SimpleFeature readFeature(Object input)
                          throws IOException

Reads a feature from GeoJSON.

Parameters:

input - The input. See GeoJSONUtil.toReader(Object) for details.

Returns:

The feature.

Throws:

IOException - In the event of a parsing error or if the input json is invalid.

readFeature

public SimpleFeature readFeature(InputStream input)
                          throws IOException

Reads a feature from GeoJSON.

This method calls through to readFeature(Object)

Parameters:

input - The input stream.

Returns:

The feature.

Throws:

IOException - In the event of a parsing error or if the input json is invalid.

writeFeatureCollection

public void writeFeatureCollection(FeatureCollection features,
                                   Object output)
                            throws IOException

Writes a feature collection as GeoJSON.

Parameters:

features - The feature collection.

output - The output. See GeoJSONUtil.toWriter(Object) for details.

Throws:

IOException

writeFeatureCollection

public void writeFeatureCollection(FeatureCollection features,
                                   OutputStream output)
                            throws IOException

Writes a feature collection as GeoJSON.

This method calls through to writeFeatureCollection(FeatureCollection, Object)

Parameters:

features - The feature collection.

output - The output strema to write to.

Throws:

IOException

readFeatureCollection

public FeatureCollection readFeatureCollection(Object input)
                                        throws IOException

Reads a feature collection from GeoJSON.

Warning that this method will load the entire feature collection into memory. For large feature collections streamFeatureCollection(Object) should be used.

Parameters:

input - The input. See GeoJSONUtil.toReader(Object) for details.

Returns:

The feature collection.

Throws:

IOException - In the event of a parsing error or if the input json is invalid.

readFeatureCollection

public FeatureCollection readFeatureCollection(InputStream input)
                                        throws IOException

Reads a feature collection from GeoJSON.

Warning that this method will load the entire feature collection into memory. For large feature collections streamFeatureCollection(Object) should be used.

This method calls through to readFeatureCollection(Object).

Parameters:

input - The input stream.

Returns:

The feature collection.

Throws:

IOException - In the event of a parsing error or if the input json is invalid.

streamFeatureCollection

public FeatureIterator<SimpleFeature> streamFeatureCollection(Object input)
                                                       throws IOException

Reads a feature collection from GeoJSON streaming back the contents via an iterator.

Parameters:

input - The input. See GeoJSONUtil.toReader(Object) for details.

Returns:

A feature iterator.

Throws:

IOException - In the event of a parsing error or if the input json is invalid.

toString

public String toString(FeatureCollection features)
                throws IOException

Writes a feature collection as GeoJSON returning the result as a string.

Parameters:

features - The feature collection.

Returns:

The feature collection encoded as GeoJSON

Throws:

IOException

writeCRS

public void writeCRS(CoordinateReferenceSystem crs,
                     Object output)
              throws IOException

Writes a coordinate reference system as GeoJSON.

Parameters:

crs - The coordinate reference system.

output - The output. See GeoJSONUtil.toWriter(Object) for details.

Throws:

IOException

writeCRS

public void writeCRS(CoordinateReferenceSystem crs,
                     OutputStream output)
              throws IOException

Writes a coordinate reference system as GeoJSON.

This method calls through to writeCRS(CoordinateReferenceSystem, Object)

Parameters:

crs - The coordinate reference system.

output - The output stream.

Throws:

IOException

readCRS

public CoordinateReferenceSystem readCRS(Object input)
                                  throws IOException

Reads a coordinate reference system from GeoJSON.

This method only handles named coordinate reference system objects.

Parameters:

input - The input. See GeoJSONUtil.toReader(Object) for details.

Returns:

The coordinate reference system.

Throws:

IOException - In the event of a parsing error or if the input json is invalid.

readCRS

public CoordinateReferenceSystem readCRS(InputStream input)
                                  throws IOException

Reads a coordinate reference system from GeoJSON.

This method only handles named coordinate reference system objects.

This method calls through to readCRS(Object)

Parameters:

input - The input. See GeoJSONUtil.toReader(Object) for details.

Returns:

The coordinate reference system.

Throws:

IOException - In the event of a parsing error or if the input json is invalid.

readFeatureCollectionSchema

public SimpleFeatureType readFeatureCollectionSchema(Object input,
                                                     boolean nullValuesEncoded)
                                              throws IOException

Reads the SimpleFeatureType of a GeoJSON feature collection. In the worst case, it will parse all features searching for attributes not present in previous features.

Parameters:

input - The input. See GeoJSONUtil.toReader(Object) for details.

nullValuesEncoded - if the input has null values encoded. If this flag is set to true and the GeoJSON doesn't actually encode null values, only the first feature attributes will be discovered.

Returns:

The feature collection schema

Throws:

IOException - In the event of a parsing error or if the input json is invalid.

readFeatureCollectionSchema

public SimpleFeatureType readFeatureCollectionSchema(InputStream input,
                                                     boolean nullValuesEncoded)
                                              throws IOException

Reads the SimpleFeatureType of a GeoJSON feature collection. In the worst case, it will parse all features searching for attributes not present in previous features.

Parameters:

input - The input. See GeoJSONUtil.toReader(Object) for details.

nullValuesEncoded - if the input has null values encoded. If this flag is set to true and the GeoJSON doesn't actually encode null values, only the first feature attributes will be discovered.

Returns:

The feature collection schema

Throws:

IOException - In the event of a parsing error or if the input json is invalid.

toString

public String toString(CoordinateReferenceSystem crs)
                throws IOException

Writes a coordinate reference system as GeoJSON returning the result as a string.

Parameters:

crs - The coordinate reference system.

Returns:

The coordinate reference system encoded as GeoJSON

Throws:

IOException