package org.geoserver.wfs.response;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import java.util.logging.Logger;
import net.opengis.wfs.FeatureCollectionType;
import net.opengis.wfs.GetFeatureType;
import net.sf.json.JSONException;
import org.geoserver.config.GeoServer;
import org.geoserver.platform.Operation;
import org.geoserver.platform.ServiceException;
import org.geoserver.wfs.GMLInfo;
import org.geoserver.wfs.WFSGetFeatureOutputFormat;
import org.geoserver.wfs.WFSInfo;
import org.geotools.feature.FeatureCollection;
import org.geotools.feature.FeatureIterator;
import org.geotools.geometry.jts.ReferencedEnvelope;
import org.geotools.referencing.NamedIdentifier;
import org.opengis.feature.simple.SimpleFeature;
import org.opengis.feature.simple.SimpleFeatureType;
import org.opengis.feature.type.AttributeDescriptor;
import org.opengis.feature.type.GeometryDescriptor;
import org.opengis.referencing.ReferenceIdentifier;
import org.opengis.referencing.crs.CoordinateReferenceSystem;
import com.vividsolutions.jts.geom.Geometry;
public class GeoJSONOutputFormat extends WFSGetFeatureOutputFormat {
private final Logger LOGGER = org.geotools.util.logging.Logging
.getLogger(this.getClass().toString());
/**
* WFS configuration
*/
private WFSInfo wfs;
public static final String FORMAT = "json";
public GeoJSONOutputFormat(GeoServer gs) {
super(FORMAT);
this.wfs = gs.getService( WFSInfo.class );
}
public String getMimeType(Object value, Operation operation)
throws ServiceException {
// let's check if a callback has been set, in that case, we need to return a different mime type
GetFeatureType gft = (GetFeatureType) operation.getParameters()[0];
String callback = (String) gft.getFormatOptions().get("CALLBACK");
if(callback != null && !"".equals(callback)) {
return "text/javascript";
} else {
return "application/json";
}
}
public String getCapabilitiesElementName() {
return "GEOJSON";
}
protected String getContentDisposition(
FeatureCollectionType featureCollection) {
StringBuffer sb = new StringBuffer();
for (Iterator f = featureCollection.getFeature().iterator(); f
.hasNext();) {
FeatureCollection fc = (FeatureCollection) f.next();
sb.append(fc.getSchema().getName().getLocalPart() + "_");
}
sb.setLength(sb.length() - 1);
return "inline; filename=" + sb.toString() + ".txt";
}
protected void write(FeatureCollectionType featureCollection,
OutputStream output, Operation getFeature) throws IOException,
ServiceException {
// TODO: investigate setting proper charsets in this
// it's part of the constructor, just need to hook it up.
Writer outWriter = new BufferedWriter(
new OutputStreamWriter(output,wfs.getGeoServer().getGlobal().getCharset()));
// let's check if a callback has been set
GetFeatureType gft = (GetFeatureType) getFeature.getParameters()[0];
String callback = (String) gft.getFormatOptions().get("CALLBACK");
if(callback != null && !"".equals(callback)) {
outWriter.write(callback + "(");
}
GeoJSONBuilder jsonWriter = new GeoJSONBuilder(outWriter);
// execute should of set all the header information
// including the lockID
//
// execute should also fail if all of the locks could not be aquired
List resultsList = featureCollection.getFeature();
// FeatureResults[] featureResults = (FeatureResults[]) resultsList
// .toArray(new FeatureResults[resultsList.size()]);
LOGGER.info("about to encode JSON");
// Generate bounds for every feature?
boolean featureBounding = wfs.isFeatureBounding();
boolean hasGeom = false;
try {
jsonWriter.object().key("type").value("FeatureCollection");
jsonWriter.key("features");
jsonWriter.array();
CoordinateReferenceSystem crs = null;
for (int i = 0; i < resultsList.size(); i++) {
FeatureCollection collection = (FeatureCollection) resultsList
.get(i);
FeatureIterator iterator = collection.features();
try {
SimpleFeatureType fType;
List<AttributeDescriptor> types;
while (iterator.hasNext()) {
SimpleFeature feature = (SimpleFeature) iterator.next();
jsonWriter.object();
jsonWriter.key("type").value("Feature");
jsonWriter.key("id").value(feature.getID());
fType = feature.getFeatureType();
types = fType.getAttributeDescriptors();
GeometryDescriptor defaultGeomType = fType.getGeometryDescriptor();
if (crs == null && defaultGeomType != null)
crs = fType.getGeometryDescriptor().getCoordinateReferenceSystem();
jsonWriter.key("geometry");
Geometry aGeom = (Geometry) feature.getDefaultGeometry();
if (aGeom == null) {
// In case the default geometry is not set, we will
// just use the first geometry we find
for (int j = 0; j < types.size() && aGeom == null; j++) {
Object value = feature.getAttribute(j);
if (value != null && value instanceof Geometry) {
aGeom = (Geometry) value;
}
}
}
// Write the geometry, whether it is a null or not
if (aGeom != null) {
jsonWriter.writeGeom(aGeom);
hasGeom = true;
} else {
jsonWriter.value(null);
}
if (defaultGeomType != null)
jsonWriter.key("geometry_name").value(
defaultGeomType.getLocalName());
jsonWriter.key("properties");
jsonWriter.object();
for (int j = 0; j < types.size(); j++) {
Object value = feature.getAttribute(j);
AttributeDescriptor ad = types.get(j);
if (value != null) {
if (value instanceof Geometry) {
// This is an area of the spec where they
// decided to 'let convention evolve',
// that is how to handle multiple
// geometries. My take is to print the
// geometry here if it's not the default.
// If it's the default that you already
// printed above, so you don't need it here.
if (ad.equals(defaultGeomType)) {
// Do nothing, we wrote it above
// jsonWriter.value("geometry_name");
} else {
jsonWriter.key(ad.getLocalName());
jsonWriter.writeGeom((Geometry) value);
}
} else {
jsonWriter.key(ad.getLocalName());
jsonWriter.value(value);
}
} else {
jsonWriter.key(ad.getLocalName());
jsonWriter.value(null);
}
}
// Bounding box for feature in properties
ReferencedEnvelope refenv = new ReferencedEnvelope(feature.getBounds());
if (featureBounding && !refenv.isEmpty())
jsonWriter.writeBoundingBox(refenv);
jsonWriter.endObject(); // end the properties
jsonWriter.endObject(); // end the feature
}
} // catch an exception here?
finally {
collection.close(iterator);
}
}
jsonWriter.endArray(); // end features
// Coordinate Referense System, currently only if the namespace is
// EPSG
if (crs != null) {
Set<ReferenceIdentifier> ids = crs.getIdentifiers();
// WKT defined crs might not have identifiers at all
if(ids != null && ids.size() > 0) {
NamedIdentifier namedIdent = (NamedIdentifier) ids.iterator().next();
String csStr = namedIdent.getCodeSpace().toUpperCase();
if (csStr.equals("EPSG")) {
jsonWriter.key("crs");
jsonWriter.object();
jsonWriter.key("type").value(csStr);
jsonWriter.key("properties");
jsonWriter.object();
jsonWriter.key("code");
jsonWriter.value(namedIdent.getCode());
jsonWriter.endObject(); // end properties
jsonWriter.endObject(); // end crs
}
}
}
// Bounding box for featurecollection
if (hasGeom) {
ReferencedEnvelope e = null;
for (int i = 0; i < resultsList.size(); i++) {
FeatureCollection collection = (FeatureCollection) resultsList
.get(i);
if (e == null) {
e = collection.getBounds();
} else {
e.expandToInclude(collection.getBounds());
}
}
if (e != null) {
jsonWriter.writeBoundingBox(e);
}
}
jsonWriter.endObject(); // end featurecollection
outWriter.flush();
if(callback != null && !"".equals(callback)) {
outWriter.write(")");
outWriter.flush();
}
} catch (JSONException jsonException) {
ServiceException serviceException = new ServiceException("Error: "
+ jsonException.getMessage());
serviceException.initCause(jsonException);
throw serviceException;
}
}
}