com.vividsolutions.jts.io.WKTWriter Maven / Gradle / Ivy
Show all versions of JTSplus Show documentation
/*
* The JTS Topology Suite is a collection of Java classes that
* implement the fundamental operations required to validate a given
* geo-spatial data set to a known topological specification.
*
* Copyright (C) 2001 Vivid Solutions
*
* 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; either
* version 2.1 of the License, or (at your option) any later version.
*
* 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.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* For more information, contact:
*
* Vivid Solutions
* Suite #1A
* 2328 Government Street
* Victoria BC V8T 5G5
* Canada
*
* (250)385-6040
* www.vividsolutions.com
*/
package com.vividsolutions.jts.io;
import com.vividsolutions.jts.geom.*;
import com.vividsolutions.jts.util.*;
import java.io.*;
import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;
/**
* Writes the Well-Known Text representation of a {@link Geometry}.
* The Well-Known Text format is defined in the
* OGC
* Simple Features Specification for SQL.
* See {@link WKTReader} for a formal specification of the format syntax.
*
* The WKTWriter outputs coordinates rounded to the precision
* model. Only the maximum number of decimal places
* necessary to represent the ordinates to the required precision will be
* output.
*
* The SFS WKT spec does not define a special tag for {@link LinearRing}s.
* Under the spec, rings are output as LINESTRINGs.
* In order to allow precisely specifying constructed geometries,
* JTS also supports a non-standard LINEARRING tag which is used
* to output LinearRings.
*
* @version 1.7
* @see WKTReader
*/
public class WKTWriter
{
/**
* Generates the WKT for a POINT
* specified by a {@link Coordinate}.
*
* @param p0 the point coordinate
*
* @return the WKT
*/
public static String toPoint(Coordinate p0)
{
return "POINT ( " + p0.x + " " + p0.y + " )";
}
/**
* Generates the WKT for a LINESTRING
* specified by a {@link CoordinateSequence}.
*
* @param seq the sequence to write
*
* @return the WKT string
*/
public static String toLineString(CoordinateSequence seq)
{
StringBuffer buf = new StringBuffer();
buf.append("LINESTRING ");
if (seq.size() == 0)
buf.append(" EMPTY");
else {
buf.append("(");
for (int i = 0; i < seq.size(); i++) {
if (i > 0)
buf.append(", ");
buf.append(seq.getX(i) + " " + seq.getY(i));
}
buf.append(")");
}
return buf.toString();
}
/**
* Generates the WKT for a LINESTRING
* specified by a {@link CoordinateSequence}.
*
* @param seq the sequence to write
*
* @return the WKT string
*/
public static String toLineString(Coordinate[] coord)
{
StringBuffer buf = new StringBuffer();
buf.append("LINESTRING ");
if (coord.length == 0)
buf.append(" EMPTY");
else {
buf.append("(");
for (int i = 0; i < coord.length; i++) {
if (i > 0)
buf.append(", ");
buf.append(coord[i].x + " " + coord[i].y );
}
buf.append(")");
}
return buf.toString();
}
/**
* Generates the WKT for a LINESTRING
* specified by two {@link Coordinate}s.
*
* @param p0 the first coordinate
* @param p1 the second coordinate
*
* @return the WKT
*/
public static String toLineString(Coordinate p0, Coordinate p1)
{
return "LINESTRING ( " + p0.x + " " + p0.y + ", " + p1.x + " " + p1.y + " )";
}
private static final int INDENT = 2;
/**
* Creates the DecimalFormat used to write doubles
* with a sufficient number of decimal places.
*
*@param precisionModel the PrecisionModel used to determine
* the number of decimal places to write.
*@return a DecimalFormat that write double
* s without scientific notation.
*/
private static DecimalFormat createFormatter(PrecisionModel precisionModel) {
// the default number of decimal places is 16, which is sufficient
// to accomodate the maximum precision of a double.
int decimalPlaces = precisionModel.getMaximumSignificantDigits();
// specify decimal separator explicitly to avoid problems in other locales
DecimalFormatSymbols symbols = new DecimalFormatSymbols();
symbols.setDecimalSeparator('.');
String fmtString = "0" + (decimalPlaces > 0 ? "." : "")
+ stringOfChar('#', decimalPlaces);
return new DecimalFormat(fmtString, symbols);
}
/**
* Returns a String of repeated characters.
*
*@param ch the character to repeat
*@param count the number of times to repeat the character
*@return a String of characters
*/
public static String stringOfChar(char ch, int count) {
StringBuffer buf = new StringBuffer();
for (int i = 0; i < count; i++) {
buf.append(ch);
}
return buf.toString();
}
private int outputDimension = 2;
private DecimalFormat formatter;
private boolean isFormatted = false;
private boolean useFormatting = false;
private int level = 0;
private int coordsPerLine = -1;
private String indentTabStr = " ";
/**
* Creates a new WKTWriter with default settings
*/
public WKTWriter()
{
}
/**
* Creates a writer that writes {@link Geometry}s with
* the given output dimension (2 or 3).
* If the specified output dimension is 3, the Z value
* of coordinates will be written if it is present
* (i.e. if it is not Double.NaN).
*
* @param outputDimension the coordinate dimension to output (2 or 3)
*/
public WKTWriter(int outputDimension) {
this.outputDimension = outputDimension;
if (outputDimension < 2 || outputDimension > 3)
throw new IllegalArgumentException("Invalid output dimension (must be 2 or 3)");
}
/**
* Sets whether the output will be formatted.
*
* @param isFormatted true if the output is to be formatted
*/
public void setFormatted(boolean isFormatted)
{
this.isFormatted = isFormatted;
}
/**
* Sets the maximum number of coordinates per line
* written in formatted output.
* If the provided coordinate number is <= 0,
* coordinates will be written all on one line.
*
* @param coordsPerLine the number of coordinates per line to output.
*/
public void setMaxCoordinatesPerLine(int coordsPerLine)
{
this.coordsPerLine = coordsPerLine;
}
/**
* Sets the tab size to use for indenting.
*
* @param size the number of spaces to use as the tab string
* @throws IllegalArgumentException if the size is non-positive
*/
public void setTab(int size)
{
if(size <= 0)
throw new IllegalArgumentException("Tab count must be positive");
this.indentTabStr = stringOfChar(' ', size);
}
/**
* Converts a Geometry to its Well-known Text representation.
*
*@param geometry a Geometry to process
*@return a string (see the OpenGIS Simple
* Features Specification)
*/
public String write(Geometry geometry)
{
Writer sw = new StringWriter();
try {
writeFormatted(geometry, isFormatted, sw);
}
catch (IOException ex) {
Assert.shouldNeverReachHere();
}
return sw.toString();
}
/**
* Converts a Geometry to its Well-known Text representation.
*
*@param geometry a Geometry to process
*/
public void write(Geometry geometry, Writer writer)
throws IOException
{
writeFormatted(geometry, false, writer);
}
/**
* Same as write, but with newlines and spaces to make the
* well-known text more readable.
*
*@param geometry a Geometry to process
*@return a string (see the OpenGIS Simple
* Features Specification), with newlines and spaces
*/
public String writeFormatted(Geometry geometry)
{
Writer sw = new StringWriter();
try {
writeFormatted(geometry, true, sw);
}
catch (IOException ex) {
Assert.shouldNeverReachHere();
}
return sw.toString();
}
/**
* Same as write, but with newlines and spaces to make the
* well-known text more readable.
*
*@param geometry a Geometry to process
*/
public void writeFormatted(Geometry geometry, Writer writer)
throws IOException
{
writeFormatted(geometry, true, writer);
}
/**
* Converts a Geometry to its Well-known Text representation.
*
*@param geometry a Geometry to process
*/
private void writeFormatted(Geometry geometry, boolean useFormatting, Writer writer)
throws IOException
{
this.useFormatting = useFormatting;
formatter = createFormatter(geometry.getPrecisionModel());
appendGeometryTaggedText(geometry, 0, writer);
}
/**
* Converts a Geometry to <Geometry Tagged Text> format,
* then appends it to the writer.
*
*@param geometry the Geometry to process
*@param writer the output writer to append to
*/
private void appendGeometryTaggedText(Geometry geometry, int level, Writer writer)
throws IOException
{
indent(level, writer);
if (geometry instanceof Point) {
Point point = (Point) geometry;
appendPointTaggedText(point.getCoordinate(), level, writer, point.getPrecisionModel());
}
else if (geometry instanceof LinearRing) {
appendLinearRingTaggedText((LinearRing) geometry, level, writer);
}
else if (geometry instanceof LineString) {
appendLineStringTaggedText((LineString) geometry, level, writer);
}
else if (geometry instanceof Polygon) {
appendPolygonTaggedText((Polygon) geometry, level, writer);
}
else if (geometry instanceof MultiPoint) {
appendMultiPointTaggedText((MultiPoint) geometry, level, writer);
}
else if (geometry instanceof MultiLineString) {
appendMultiLineStringTaggedText((MultiLineString) geometry, level, writer);
}
else if (geometry instanceof MultiPolygon) {
appendMultiPolygonTaggedText((MultiPolygon) geometry, level, writer);
}
else if (geometry instanceof GeometryCollection) {
appendGeometryCollectionTaggedText((GeometryCollection) geometry, level, writer);
}
else {
Assert.shouldNeverReachHere("Unsupported Geometry implementation:"
+ geometry.getClass());
}
}
/**
* Converts a Coordinate to <Point Tagged Text> format,
* then appends it to the writer.
*
*@param coordinate the Coordinate to process
*@param writer the output writer to append to
*@param precisionModel the PrecisionModel to use to convert
* from a precise coordinate to an external coordinate
*/
private void appendPointTaggedText(Coordinate coordinate, int level, Writer writer,
PrecisionModel precisionModel)
throws IOException
{
writer.write("POINT ");
appendPointText(coordinate, level, writer, precisionModel);
}
/**
* Converts a LineString to <LineString Tagged Text>
* format, then appends it to the writer.
*
*@param lineString the LineString to process
*@param writer the output writer to append to
*/
private void appendLineStringTaggedText(LineString lineString, int level, Writer writer)
throws IOException
{
writer.write("LINESTRING ");
appendLineStringText(lineString, level, false, writer);
}
/**
* Converts a LinearRing to <LinearRing Tagged Text>
* format, then appends it to the writer.
*
*@param linearRing the LinearRing to process
*@param writer the output writer to append to
*/
private void appendLinearRingTaggedText(LinearRing linearRing, int level, Writer writer)
throws IOException
{
writer.write("LINEARRING ");
appendLineStringText(linearRing, level, false, writer);
}
/**
* Converts a Polygon to <Polygon Tagged Text> format,
* then appends it to the writer.
*
*@param polygon the Polygon to process
*@param writer the output writer to append to
*/
private void appendPolygonTaggedText(Polygon polygon, int level, Writer writer)
throws IOException
{
writer.write("POLYGON ");
appendPolygonText(polygon, level, false, writer);
}
/**
* Converts a MultiPoint to <MultiPoint Tagged Text>
* format, then appends it to the writer.
*
*@param multipoint the MultiPoint to process
*@param writer the output writer to append to
*/
private void appendMultiPointTaggedText(MultiPoint multipoint, int level, Writer writer)
throws IOException
{
writer.write("MULTIPOINT ");
appendMultiPointText(multipoint, level, writer);
}
/**
* Converts a MultiLineString to <MultiLineString Tagged
* Text> format, then appends it to the writer.
*
*@param multiLineString the MultiLineString to process
*@param writer the output writer to append to
*/
private void appendMultiLineStringTaggedText(MultiLineString multiLineString, int level,
Writer writer)
throws IOException
{
writer.write("MULTILINESTRING ");
appendMultiLineStringText(multiLineString, level, false, writer);
}
/**
* Converts a MultiPolygon to <MultiPolygon Tagged Text>
* format, then appends it to the writer.
*
*@param multiPolygon the MultiPolygon to process
*@param writer the output writer to append to
*/
private void appendMultiPolygonTaggedText(MultiPolygon multiPolygon, int level, Writer writer)
throws IOException
{
writer.write("MULTIPOLYGON ");
appendMultiPolygonText(multiPolygon, level, writer);
}
/**
* Converts a GeometryCollection to <GeometryCollection
* Tagged Text> format, then appends it to the writer.
*
*@param geometryCollection the GeometryCollection to process
*@param writer the output writer to append to
*/
private void appendGeometryCollectionTaggedText(GeometryCollection geometryCollection, int level,
Writer writer)
throws IOException
{
writer.write("GEOMETRYCOLLECTION ");
appendGeometryCollectionText(geometryCollection, level, writer);
}
/**
* Converts a Coordinate to <Point Text> format, then
* appends it to the writer.
*
*@param coordinate the Coordinate to process
*@param writer the output writer to append to
*@param precisionModel the PrecisionModel to use to convert
* from a precise coordinate to an external coordinate
*/
private void appendPointText(Coordinate coordinate, int level, Writer writer,
PrecisionModel precisionModel)
throws IOException
{
if (coordinate == null) {
writer.write("EMPTY");
}
else {
writer.write("(");
appendCoordinate(coordinate, writer);
writer.write(")");
}
}
/**
* Appends the i'th coordinate from the sequence to the writer
*
* @param seq the CoordinateSequence to process
* @param i the index of the coordinate to write
* @param writer the output writer to append to
*/
private void appendCoordinate(CoordinateSequence seq, int i, Writer writer)
throws IOException
{
writer.write(writeNumber(seq.getX(i)) + " " + writeNumber(seq.getY(i)));
if (outputDimension >= 3 && seq.getDimension() >= 3) {
double z = seq.getOrdinate(i, 3);
if (! Double.isNaN(z)) {
writer.write(" ");
writer.write(writeNumber(z));
}
}
}
/**
* Converts a Coordinate to <Point> format,
* then appends it to the writer.
*
*@param coordinate the Coordinate to process
*@param writer the output writer to append to
*/
private void appendCoordinate(Coordinate coordinate, Writer writer)
throws IOException
{
writer.write(writeNumber(coordinate.x) + " " + writeNumber(coordinate.y));
if (outputDimension >= 3 && ! Double.isNaN(coordinate.z)) {
writer.write(" ");
writer.write(writeNumber(coordinate.z));
}
}
/**
* Converts a double to a String, not in scientific
* notation.
*
*@param d the double to convert
*@return the double as a String, not in
* scientific notation
*/
private String writeNumber(double d) {
return formatter.format(d);
}
/**
* Converts a LineString to <LineString Text> format, then
* appends it to the writer.
*
*@param lineString the LineString to process
*@param writer the output writer to append to
*/
private void appendSequenceText(CoordinateSequence seq, int level, boolean doIndent, Writer writer)
throws IOException
{
if (seq.size() == 0) {
writer.write("EMPTY");
}
else {
if (doIndent) indent(level, writer);
writer.write("(");
for (int i = 0; i < seq.size(); i++) {
if (i > 0) {
writer.write(", ");
if (coordsPerLine > 0
&& i % coordsPerLine == 0) {
indent(level + 1, writer);
}
}
appendCoordinate(seq, i, writer);
}
writer.write(")");
}
}
/**
* Converts a LineString to <LineString Text> format, then
* appends it to the writer.
*
*@param lineString the LineString to process
*@param writer the output writer to append to
*/
private void appendLineStringText(LineString lineString, int level, boolean doIndent, Writer writer)
throws IOException
{
if (lineString.isEmpty()) {
writer.write("EMPTY");
}
else {
if (doIndent) indent(level, writer);
writer.write("(");
for (int i = 0; i < lineString.getNumPoints(); i++) {
if (i > 0) {
writer.write(", ");
if (coordsPerLine > 0
&& i % coordsPerLine == 0) {
indent(level + 1, writer);
}
}
appendCoordinate(lineString.getCoordinateN(i), writer);
}
writer.write(")");
}
}
/**
* Converts a Polygon to <Polygon Text> format, then
* appends it to the writer.
*
*@param polygon the Polygon to process
*@param writer the output writer to append to
*/
private void appendPolygonText(Polygon polygon, int level, boolean indentFirst, Writer writer)
throws IOException
{
if (polygon.isEmpty()) {
writer.write("EMPTY");
}
else {
if (indentFirst) indent(level, writer);
writer.write("(");
appendLineStringText(polygon.getExteriorRing(), level, false, writer);
for (int i = 0; i < polygon.getNumInteriorRing(); i++) {
writer.write(", ");
appendLineStringText(polygon.getInteriorRingN(i), level + 1, true, writer);
}
writer.write(")");
}
}
/**
* Converts a MultiPoint to <MultiPoint Text> format, then
* appends it to the writer.
*
*@param multiPoint the MultiPoint to process
*@param writer the output writer to append to
*/
private void appendMultiPointText(MultiPoint multiPoint, int level, Writer writer)
throws IOException
{
if (multiPoint.isEmpty()) {
writer.write("EMPTY");
}
else {
writer.write("(");
for (int i = 0; i < multiPoint.getNumGeometries(); i++) {
if (i > 0) {
writer.write(", ");
indentCoords(i, level + 1, writer);
}
writer.write("(");
appendCoordinate(((Point) multiPoint.getGeometryN(i)).getCoordinate(), writer);
writer.write(")");
}
writer.write(")");
}
}
/**
* Converts a MultiLineString to <MultiLineString Text>
* format, then appends it to the writer.
*
*@param multiLineString the MultiLineString to process
*@param writer the output writer to append to
*/
private void appendMultiLineStringText(MultiLineString multiLineString, int level, boolean indentFirst,
Writer writer)
throws IOException
{
if (multiLineString.isEmpty()) {
writer.write("EMPTY");
}
else {
int level2 = level;
boolean doIndent = indentFirst;
writer.write("(");
for (int i = 0; i < multiLineString.getNumGeometries(); i++) {
if (i > 0) {
writer.write(", ");
level2 = level + 1;
doIndent = true;
}
appendLineStringText((LineString) multiLineString.getGeometryN(i), level2, doIndent, writer);
}
writer.write(")");
}
}
/**
* Converts a MultiPolygon to <MultiPolygon Text> format,
* then appends it to the writer.
*
*@param multiPolygon the MultiPolygon to process
*@param writer the output writer to append to
*/
private void appendMultiPolygonText(MultiPolygon multiPolygon, int level, Writer writer)
throws IOException
{
if (multiPolygon.isEmpty()) {
writer.write("EMPTY");
}
else {
int level2 = level;
boolean doIndent = false;
writer.write("(");
for (int i = 0; i < multiPolygon.getNumGeometries(); i++) {
if (i > 0) {
writer.write(", ");
level2 = level + 1;
doIndent = true;
}
appendPolygonText((Polygon) multiPolygon.getGeometryN(i), level2, doIndent, writer);
}
writer.write(")");
}
}
/**
* Converts a GeometryCollection to <GeometryCollectionText>
* format, then appends it to the writer.
*
*@param geometryCollection the GeometryCollection to process
*@param writer the output writer to append to
*/
private void appendGeometryCollectionText(GeometryCollection geometryCollection, int level,
Writer writer)
throws IOException
{
if (geometryCollection.isEmpty()) {
writer.write("EMPTY");
}
else {
int level2 = level;
writer.write("(");
for (int i = 0; i < geometryCollection.getNumGeometries(); i++) {
if (i > 0) {
writer.write(", ");
level2 = level + 1;
}
appendGeometryTaggedText(geometryCollection.getGeometryN(i), level2, writer);
}
writer.write(")");
}
}
private void indentCoords(int coordIndex, int level, Writer writer)
throws IOException
{
if (coordsPerLine <= 0
|| coordIndex % coordsPerLine != 0)
return;
indent(level, writer);
}
private void indent(int level, Writer writer)
throws IOException
{
if (! useFormatting || level <= 0)
return;
writer.write("\n");
for (int i = 0; i < level; i++) {
writer.write(indentTabStr);
}
}
}