com.vividsolutions.jts.io.kml.KMLWriter Maven / Gradle / Ivy
package com.vividsolutions.jts.io.kml;
import java.io.IOException;
import java.io.Writer;
import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;
import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.Geometry;
import com.vividsolutions.jts.geom.GeometryCollection;
import com.vividsolutions.jts.geom.LineString;
import com.vividsolutions.jts.geom.LinearRing;
import com.vividsolutions.jts.geom.Point;
import com.vividsolutions.jts.geom.Polygon;
import com.vividsolutions.jts.util.StringUtil;
/**
* Writes a formatted string containing the KML representation of a JTS
* {@link Geometry}.
* The output is KML fragments which
* can be substituted wherever the KML Geometry abstract element can be used.
*
* Output elements are indented to provide a
* nicely-formatted representation.
* An output line prefix and maximum
* number of coordinates per line can be specified.
*
* The Z ordinate value output can be forced to be a specific value.
* The extrude and altitudeMode modes can be set.
* If set, the corresponding sub-elements will be output.
*/
public class KMLWriter
{
/**
* The KML standard value clampToGround for use in {@link #setAltitudeMode(String)}.
*/
public static String ALTITUDE_MODE_CLAMPTOGROUND = "clampToGround ";
/**
* The KML standard value relativeToGround for use in {@link #setAltitudeMode(String)}.
*/
public static String ALTITUDE_MODE_RELATIVETOGROUND = "relativeToGround ";
/**
* The KML standard value absolute for use in {@link #setAltitudeMode(String)}.
*/
public static String ALTITUDE_MODE_ABSOLUTE = "absolute";
/**
* Writes a Geometry as KML to a string, using
* a specified Z value.
*
* @param geometry the geometry to write
* @param z the Z value to use
* @return a string containing the KML geometry representation
*/
public static String writeGeometry(Geometry geometry, double z) {
KMLWriter writer = new KMLWriter();
writer.setZ(z);
return writer.write(geometry);
}
/**
* Writes a Geometry as KML to a string, using
* a specified Z value, precision, extrude flag,
* and altitude mode code.
*
* @param geometry the geometry to write
* @param z the Z value to use
* @param precision the maximum number of decimal places to write
* @param extrude the extrude flag to write
* @param altitudeMode the altitude model code to write
* @return a string containing the KML geometry representation
*/
public static String writeGeometry(Geometry geometry, double z, int precision,
boolean extrude, String altitudeMode) {
KMLWriter writer = new KMLWriter();
writer.setZ(z);
writer.setPrecision(precision);
writer.setExtrude(extrude);
writer.setAltitudeMode(altitudeMode);
return writer.write(geometry);
}
private final int INDENT_SIZE = 2;
private static final String COORDINATE_SEPARATOR = ",";
private static final String TUPLE_SEPARATOR = " ";
private String linePrefix = null;
private int maxCoordinatesPerLine = 5;
private double zVal = Double.NaN;
private boolean extrude = false;
private boolean tesselate;
private String altitudeMode = null;
private DecimalFormat numberFormatter = null;
/**
* Creates a new writer.
*/
public KMLWriter() {
}
/**
* Sets a tag string which is prefixed to every emitted text line.
* This can be used to indent the geometry text in a containing document.
*
* @param linePrefix the tag string
*/
public void setLinePrefix(String linePrefix) {
this.linePrefix = linePrefix;
}
/**
* Sets the maximum number of coordinates to output per line.
*
* @param maxCoordinatesPerLine the maximum number of coordinates to output
*/
public void setMaximumCoordinatesPerLine(int maxCoordinatesPerLine) {
if (maxCoordinatesPerLine <= 0) {
maxCoordinatesPerLine = 1;
return;
}
this.maxCoordinatesPerLine = maxCoordinatesPerLine;
}
/**
* Sets the Z value to be output for all coordinates.
* This overrides any Z value present in the Geometry coordinates.
*
* @param zVal the Z value to output
*/
public void setZ(double zVal) {
this.zVal = zVal;
}
/**
* Sets the flag to be output in the extrude element.
*
* @param extrude the extrude flag to output
*/
public void setExtrude(boolean extrude) {
this.extrude = extrude;
}
/**
* Sets the flag to be output in the tesselate element.
*
* @param tesselate the tesselate flag to output
*/
public void setTesselate(boolean tesselate) {
this.tesselate = tesselate;
}
/**
* Sets the value output in the altitudeMode element.
*
* @param altitudeMode string representing the altitude mode
*/
public void setAltitudeMode(String altitudeMode) {
this.altitudeMode = altitudeMode;
}
/**
* Sets the maximum nummber of decimal places to output in ordinate values.
* Useful for limiting output size.
*
* @param precision the number of decimal places to output
*/
public void setPrecision(int precision) {
//this.precision = precision;
if (precision >= 0)
numberFormatter = createFormatter(precision);
}
/**
* Writes a {@link Geometry} in KML format as a string.
*
* @param geom the geometry to write
* @return a string containing the KML geometry representation
*/
public String write(Geometry geom) {
StringBuffer buf = new StringBuffer();
write(geom, buf);
return buf.toString();
}
/**
* Writes the KML representation of a {@link Geometry} to a {@link Writer}.
*
* @param geometry the geometry to write
* @param writer the Writer to write to
* @throws IOException if an I/O error occurred
*/
public void write(Geometry geometry, Writer writer) throws IOException {
writer.write(write(geometry));
}
/**
* Appends the KML representation of a {@link Geometry} to a {@link StringBuffer}.
*
* @param geometry the geometry to write
* @param buf the buffer to write into
*/
public void write(Geometry geometry, StringBuffer buf) {
writeGeometry(geometry, 0, buf);
}
private void writeGeometry(Geometry g, int level, StringBuffer buf) {
String attributes = "";
if (g instanceof Point) {
writePoint((Point) g, attributes, level, buf);
} else if (g instanceof LinearRing) {
writeLinearRing((LinearRing) g, attributes, true, level, buf);
} else if (g instanceof LineString) {
writeLineString((LineString) g, attributes, level, buf);
} else if (g instanceof Polygon) {
writePolygon((Polygon) g, attributes, level, buf);
} else if (g instanceof GeometryCollection) {
writeGeometryCollection((GeometryCollection) g, attributes, level, buf);
}
else
throw new IllegalArgumentException("Geometry type not supported: " + g.getGeometryType());
}
private void startLine(String text, int level, StringBuffer buf) {
if (linePrefix != null)
buf.append(linePrefix);
buf.append(StringUtil.spaces(INDENT_SIZE * level));
buf.append(text);
}
private String geometryTag(String geometryName, String attributes) {
StringBuffer buf = new StringBuffer();
buf.append("<");
buf.append(geometryName);
if (attributes != null && attributes.length() > 0) {
buf.append(" ");
buf.append(attributes);
}
buf.append(">");
return buf.toString();
}
private void writeModifiers(int level, StringBuffer buf)
{
if (extrude) {
startLine("1 \n", level, buf);
}
if (tesselate) {
startLine("1 \n", level, buf);
}
if (altitudeMode != null) {
startLine("" + altitudeMode + " \n", level, buf);
}
}
private void writePoint(Point p, String attributes, int level,
StringBuffer buf) {
// ... ... ... \n", level, buf);
writeLinearRing((LinearRing) p.getExteriorRing(), null, false, level + 1, buf);
startLine(" \n", level, buf);
for (int t = 0; t < p.getNumInteriorRing(); t++) {
startLine(" \n", level, buf);
writeLinearRing((LinearRing) p.getInteriorRingN(t), null, false, level + 1, buf);
startLine(" \n", level, buf);
}
startLine("\n", level, buf);
}
private void writeGeometryCollection(GeometryCollection gc,
String attributes, int level, StringBuffer buf) {
startLine("\n", level, buf);
for (int t = 0; t < gc.getNumGeometries(); t++) {
writeGeometry(gc.getGeometryN(t), level + 1, buf);
}
startLine(" \n", level, buf);
}
/**
* Takes a list of coordinates and converts it to KML.
* 2d and 3d aware. Terminates the coordinate output with a newline.
*
* @param cs array of coordinates
*/
private void write(Coordinate[] coords, int level, StringBuffer buf) {
startLine("", level, buf);
boolean isNewLine = false;
for (int i = 0; i < coords.length; i++) {
if (i > 0) {
buf.append(TUPLE_SEPARATOR);
}
if (isNewLine) {
startLine(" ", level, buf);
isNewLine = false;
}
write(coords[i], buf);
// break output lines to prevent them from getting too long
if ((i + 1) % maxCoordinatesPerLine == 0 && i < coords.length - 1) {
buf.append("\n");
isNewLine = true;
}
}
buf.append(" \n");
}
private void write(Coordinate p, StringBuffer buf) {
write(p.x, buf);
buf.append(COORDINATE_SEPARATOR);
write(p.y, buf);
double z = p.z;
// if altitude was specified directly, use it
if (!Double.isNaN(zVal))
z = zVal;
// only write if Z present
// MD - is this right? Or should it always be written?
if (!Double.isNaN(z)) {
buf.append(COORDINATE_SEPARATOR);
write(z, buf);
}
}
private void write(double num, StringBuffer buf) {
if (numberFormatter != null)
buf.append(numberFormatter.format(num));
else
buf.append(num);
}
/**
* 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(int precision) {
// specify decimal separator explicitly to avoid problems in other locales
DecimalFormatSymbols symbols = new DecimalFormatSymbols();
symbols.setDecimalSeparator('.');
DecimalFormat format = new DecimalFormat("0."
+ StringUtil.chars('#', precision), symbols);
format.setDecimalSeparatorAlwaysShown(false);
return format;
}
}