/**
* Find the generic geometry type of the feature collection. Simple method - find the 1st non null
* geometry and its type is the generic type. returns 0 - all empty/invalid <br>
* 1 - point <br>
* 2 - line <br>
* 3 - polygon <br>
*
* @param fc feature collection containing tet geometries.
*/
int findBestGeometryType(FeatureCollection fc) {
Geometry geom;
for (Iterator i = fc.iterator(); i.hasNext(); ) {
geom = ((Feature) i.next()).getGeometry();
if (geom instanceof Point) {
return 1;
}
if (geom instanceof MultiPoint) {
return 1;
}
if (geom instanceof Polygon) {
return 3;
}
if (geom instanceof MultiPolygon) {
return 3;
}
if (geom instanceof LineString) {
return 2;
}
if (geom instanceof MultiLineString) {
return 2;
}
}
return 0;
}
/**
* look at all the data in the column of the featurecollection, and find the largest string!
*
* @param fc features to look at
* @param attributeNumber which of the column to test.
*/
int findMaxStringLength(FeatureCollection fc, int attributeNumber) {
int l;
int maxlen = 0;
Feature f;
for (Iterator i = fc.iterator(); i.hasNext(); ) {
f = (Feature) i.next();
l = f.getString(attributeNumber).length();
if (l > maxlen) {
maxlen = l;
}
}
return maxlen;
}
/**
* return a single geometry collection <br>
* result.GeometryN(i) = the i-th feature in the FeatureCollection<br>
* All the geometry types will be the same type (ie. all polygons) - or they will be set to<br>
* NULL geometries<br>
* <br>
* GeometryN(i) = {Multipoint,Multilinestring, or Multipolygon)<br>
*
* @param fc feature collection to make homogeneous
*/
public GeometryCollection makeSHAPEGeometryCollection(FeatureCollection fc) throws Exception {
GeometryCollection result;
Geometry[] allGeoms = new Geometry[fc.size()];
int geomtype = findBestGeometryType(fc);
if (geomtype == 0) {
throw new Exception(
"Could not determine shapefile type - data is either all GeometryCollections or empty");
}
List features = fc.getFeatures();
for (int t = 0; t < features.size(); t++) {
Geometry geom;
geom = ((Feature) features.get(t)).getGeometry();
switch (geomtype) {
case 1: // point
if ((geom instanceof Point)) {
// good!
Point[] p = new Point[1];
p[0] = (Point) geom;
allGeoms[t] = new MultiPoint(p, new PrecisionModel(), 0);
} else if (geom instanceof MultiPoint) {
allGeoms[t] = geom;
} else {
allGeoms[t] = new MultiPoint(null, new PrecisionModel(), 0);
}
break;
case 2: // line
if ((geom instanceof LineString)) {
LineString[] l = new LineString[1];
l[0] = (LineString) geom;
allGeoms[t] = new MultiLineString(l, new PrecisionModel(), 0);
} else if (geom instanceof MultiLineString) {
allGeoms[t] = geom;
} else {
allGeoms[t] = new MultiLineString(null, new PrecisionModel(), 0);
}
break;
case 3: // polygon
if (geom instanceof Polygon) {
// good!
Polygon[] p = new Polygon[1];
p[0] = (Polygon) geom;
allGeoms[t] = makeGoodSHAPEMultiPolygon(new MultiPolygon(p, new PrecisionModel(), 0));
} else if (geom instanceof MultiPolygon) {
allGeoms[t] = makeGoodSHAPEMultiPolygon((MultiPolygon) geom);
} else {
allGeoms[t] = new MultiPolygon(null, new PrecisionModel(), 0);
}
break;
}
}
result = new GeometryCollection(allGeoms, new PrecisionModel(), 0);
return result;
}
/**
* Write a dbf file with the information from the featureCollection.
*
* @param featureCollection column data from collection
* @param fname name of the dbf file to write to
*/
void writeDbf(FeatureCollection featureCollection, String fname) throws Exception {
DbfFileWriter dbf;
FeatureSchema fs;
int t;
int f;
int u;
int num;
fs = featureCollection.getFeatureSchema();
// -1 because one of the columns is geometry
DbfFieldDef[] fields = new DbfFieldDef[fs.getAttributeCount() - 1];
// dbf column type and size
f = 0;
for (t = 0; t < fs.getAttributeCount(); t++) {
AttributeType columnType = fs.getAttributeType(t);
String columnName = fs.getAttributeName(t);
if (columnType == AttributeType.INTEGER) {
fields[f] = new DbfFieldDef(columnName, 'N', 16, 0);
f++;
} else if (columnType == AttributeType.DOUBLE) {
fields[f] = new DbfFieldDef(columnName, 'N', 33, 16);
f++;
} else if (columnType == AttributeType.STRING) {
int maxlength = findMaxStringLength(featureCollection, t);
if (maxlength > 255) {
throw new Exception(
"ShapefileWriter does not support strings longer than 255 characters");
}
fields[f] = new DbfFieldDef(columnName, 'C', maxlength, 0);
f++;
} else if (columnType == AttributeType.DATE) {
fields[f] = new DbfFieldDef(columnName, 'D', 8, 0);
f++;
} else if (columnType == AttributeType.GEOMETRY) {
// do nothing - the .shp file handles this
} else {
throw new Exception("Shapewriter: unsupported AttributeType found in featurecollection.");
}
}
// write header
dbf = new DbfFileWriter(fname);
dbf.writeHeader(fields, featureCollection.size());
// write rows
num = featureCollection.size();
List features = featureCollection.getFeatures();
for (t = 0; t < num; t++) {
// System.out.println("dbf: record "+t);
Feature feature = (Feature) features.get(t);
Vector DBFrow = new Vector();
// make data for each column in this feature (row)
for (u = 0; u < fs.getAttributeCount(); u++) {
AttributeType columnType = fs.getAttributeType(u);
if (columnType == AttributeType.INTEGER) {
Object a = feature.getAttribute(u);
if (a == null) {
DBFrow.add(new Integer(0));
} else {
DBFrow.add((Integer) a);
}
} else if (columnType == AttributeType.DOUBLE) {
Object a = feature.getAttribute(u);
if (a == null) {
DBFrow.add(new Double(0.0));
} else {
DBFrow.add((Double) a);
}
} else if (columnType == AttributeType.DATE) {
Object a = feature.getAttribute(u);
if (a == null) {
DBFrow.add("");
} else {
DBFrow.add(DbfFile.DATE_PARSER.format((Date) a));
}
} else if (columnType == AttributeType.STRING) {
Object a = feature.getAttribute(u);
if (a == null) {
DBFrow.add(new String(""));
} else {
// MD 16 jan 03 - added some defensive programming
if (a instanceof String) {
DBFrow.add(a);
} else {
DBFrow.add(a.toString());
}
}
}
}
dbf.writeRecord(DBFrow);
}
dbf.close();
}