/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2002-2011, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package org.geotools.data.shapefile.ng;
import java.io.IOException;
import java.util.List;
import java.util.Map;
import java.util.NoSuchElementException;
import org.geotools.data.FeatureReader;
import org.geotools.data.shapefile.ng.dbf.DbaseFileHeader;
import org.geotools.data.shapefile.ng.dbf.DbaseFileReader;
import org.geotools.data.shapefile.ng.dbf.DbaseFileReader.Row;
import org.geotools.data.shapefile.ng.fid.IndexedFidReader;
import org.geotools.data.shapefile.ng.shp.ShapeType;
import org.geotools.data.shapefile.ng.shp.ShapefileReader;
import org.geotools.data.shapefile.ng.shp.ShapefileReader.Record;
import org.geotools.feature.simple.SimpleFeatureBuilder;
import org.geotools.renderer.ScreenMap;
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 com.vividsolutions.jts.geom.Envelope;
import com.vividsolutions.jts.geom.Geometry;
class ShapefileFeatureReader implements FeatureReader<SimpleFeatureType, SimpleFeature> {
SimpleFeatureType schema;
ShapefileReader shp;
DbaseFileReader dbf;
int[] dbfindexes;
SimpleFeatureBuilder builder;
SimpleFeature nextFeature;
Envelope targetBBox;
double simplificationDistance;
ScreenMap screenMap;
StringBuffer idxBuffer;
int idxBaseLen;
IndexedFidReader fidReader;
public ShapefileFeatureReader(SimpleFeatureType schema, ShapefileReader shp, DbaseFileReader dbf, IndexedFidReader fidReader)
throws IOException {
this.schema = schema;
this.shp = shp;
this.dbf = dbf;
this.fidReader = fidReader;
this.builder = new SimpleFeatureBuilder(schema);
idxBuffer = new StringBuffer(schema.getTypeName());
idxBuffer.append('.');
idxBaseLen = idxBuffer.length();
if (dbf != null) {
// build the list of dbf indexes we have to read taking into consideration the
// duplicated dbf field names issue
List<AttributeDescriptor> atts = schema.getAttributeDescriptors();
dbfindexes = new int[atts.size()];
DbaseFileHeader head = dbf.getHeader();
for (int i = 0; i < atts.size(); i++) {
AttributeDescriptor att = atts.get(i);
if (att instanceof GeometryDescriptor) {
dbfindexes[i] = -1;
} else {
String attName = att.getLocalName();
int count = 0;
Map<Object, Object> userData = att.getUserData();
if (userData.get(ShapefileDataStore.ORIGINAL_FIELD_NAME) != null) {
attName = (String) userData.get(ShapefileDataStore.ORIGINAL_FIELD_NAME);
count = (Integer) userData
.get(ShapefileDataStore.ORIGINAL_FIELD_DUPLICITY_COUNT);
}
boolean found = false;
for (int j = 0; j < head.getNumFields(); j++) {
if (head.getFieldName(j).equals(attName) && count-- <= 0) {
dbfindexes[i] = j;
found = true;
break;
}
}
if (!found) {
throw new IOException("Could not find attribute " + attName
+ " (mul count: " + count);
}
}
}
}
}
@Override
public SimpleFeatureType getFeatureType() {
return schema;
}
@Override
public SimpleFeature next() throws IOException, IllegalArgumentException,
NoSuchElementException {
if (hasNext()) {
SimpleFeature result = nextFeature;
nextFeature = null;
return result;
} else {
throw new NoSuchElementException("hasNext() returned false");
}
}
/**
* Returns true if the lower level readers, shp and dbf, have one more record to read
*
* @return
* @throws IOException
*/
boolean filesHaveMore() throws IOException {
if (dbf == null) {
return shp.hasNext();
} else {
boolean dbfHasNext = dbf.hasNext();
boolean shpHasNext = shp.hasNext();
if (dbfHasNext && shpHasNext) {
return true;
} else if (dbfHasNext || shpHasNext) {
throw new IOException(((shpHasNext) ? "Shp" : "Dbf") + " has extra record");
} else {
return false;
}
}
}
@Override
public boolean hasNext() throws IOException {
while (nextFeature == null && filesHaveMore()) {
Record record = shp.nextRecord();
// read the geometry, so that we can decide if this row is to be skipped or not
Envelope envelope = record.envelope();
boolean skip = false;
Geometry geometry = null;
if(schema.getGeometryDescriptor() != null) {
// ... if geometry is out of the target bbox, skip both geom and row
if (targetBBox != null && !targetBBox.isNull() && !targetBBox.intersects(envelope)) {
skip = true;
// ... if the geometry is awfully small avoid reading it (unless it's a point)
} else if (simplificationDistance > 0 && envelope.getWidth() < simplificationDistance
&& envelope.getHeight() < simplificationDistance) {
try {
if (screenMap != null && screenMap.checkAndSet(envelope)) {
geometry = null;
skip = true;
} else {
// if we are using the screenmap better provide a slightly modified
// version of the geometry bounds or we'll end up with many holes
// in the rendering
geometry = (Geometry) record.getSimplifiedShape(screenMap);
}
} catch (Exception e) {
geometry = (Geometry) record.getSimplifiedShape();
}
// ... otherwise business as usual
} else {
geometry = (Geometry) record.shape();
}
}
if (!skip) {
// also grab the dbf row
Row row;
if (dbf != null) {
row = dbf.readRow();
} else {
row = null;
}
nextFeature = buildFeature(record.number, geometry, row);
} else {
if (dbf != null) {
dbf.skip();
}
}
}
return nextFeature != null;
}
SimpleFeature buildFeature(int number, Geometry geometry, Row row) throws IOException {
if (dbfindexes != null) {
for (int i = 0; i < dbfindexes.length; i++) {
if (dbfindexes[i] == -1) {
builder.add(geometry);
} else {
builder.add(row.read(dbfindexes[i]));
}
}
} else if(geometry != null) {
builder.add(geometry);
}
// build the feature id
String featureId = buildFeatureId(number);
return builder.buildFeature(featureId);
}
protected String buildFeatureId(int number) throws IOException {
if(fidReader == null) {
idxBuffer.delete(idxBaseLen, idxBuffer.length());
idxBuffer.append(number);
return idxBuffer.toString();
} else {
fidReader.goTo(number - 1);
return fidReader.next();
}
}
@Override
public void close() throws IOException {
try {
if (shp != null) {
shp.close();
}
} finally {
try {
if (dbf != null) {
dbf.close();
}
} finally {
shp = null;
dbf = null;
}
}
}
/**
* Sets the target bbox, will be used to skip over features we do not need
*
* @param targetBBox
*/
public void setTargetBBox(Envelope targetBBox) {
this.targetBBox = targetBBox;
}
/**
* Sets the simplification distance, the reader will subsample pixels on the go
*
* @param simplificationDistance
*/
public void setSimplificationDistance(double simplificationDistance) {
this.simplificationDistance = simplificationDistance;
}
/**
* Sets the screen map, will be used to skip over features that are too small
*
* @param screenMap
*/
public void setScreenMap(ScreenMap screenMap) {
this.screenMap = screenMap;
}
void disableShxUsage() throws IOException {
this.shp.disableShxUsage();
}
ShapeType getShapeType() {
return shp.getHeader().getShapeType();
}
}