org.geotoolkit.io.wkt.PrjFiles Maven / Gradle / Ivy
/*
* Geotoolkit.org - An Open Source Java GIS Toolkit
* http://www.geotoolkit.org
*
* (C) 2009-2012, Open Source Geospatial Foundation (OSGeo)
* (C) 2009-2012, Geomatys
*
* 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.geotoolkit.io.wkt;
import java.io.*;
import java.net.URL;
import java.nio.channels.Channels;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.WritableByteChannel;
import org.opengis.util.FactoryException;
import org.opengis.referencing.crs.CoordinateReferenceSystem;
import org.geotoolkit.lang.Static;
import org.geotoolkit.referencing.CRS;
import org.geotoolkit.resources.Errors;
import org.geotoolkit.io.ContentFormatException;
/**
* Parses and formats PRJ files. Those files usually have the {@code ".prj"} suffix and contain
* the definition of exactly one Coordinate Reference System (CRS) in Well
* Known Text (WKT) format. This class allows the definition to span many lines, but the
* common practice is to provide the full WKT string on a single line.
*
* If the definition is not a valid WKT string (during reads), or if a CRS can not be formatted as
* a WKT (during writes), then the methods in this class throw a {@link ContentFormatException}.
* This is a subclass of {@link IOException} and consequently does not require a try …
* catch block different than the one for normal I/O operations.
*
* Every files are expected to use the ISO-8859-1 (a.k.a. ISO-LATIN-1) encoding.
*
* @author Martin Desruisseaux (Geomatys)
* @version 3.07
*
* @since 3.05
* @module
*/
public final class PrjFiles extends Static {
/**
* The encoding of PRJ files.
*/
private static final String ENCODING = "ISO-8859-1";
/**
* Do not allow instantiation of this class.
*/
private PrjFiles() {
}
/**
* Parses a PRJ file and returns its content as a coordinate reference system.
*
* @param file The file to parse. It usually has the {@code ".prj"} suffix,
* @return The PRJ file content as a coordinate reference system.
* @throws ContentFormatException If the content of the PRJ file is an invalid WKT.
* @throws IOException If the parsing failed for an other raison.
*/
public static CoordinateReferenceSystem read(final File file) throws ContentFormatException, IOException {
return read(new FileInputStream(file), true);
}
/**
* Parses a PRJ file from a URL and returns its content as a coordinate reference system.
*
* @param file The file to parse. It usually has the {@code ".prj"} suffix,
* @return The PRJ file content as a coordinate reference system.
* @throws ContentFormatException If the content of the PRJ file is an invalid WKT.
* @throws IOException If the parsing failed for an other raison.
*/
public static CoordinateReferenceSystem read(final URL file) throws ContentFormatException, IOException {
return read(file.openStream(), true);
}
/**
* Parses a PRJ file from a channel and returns its content as a coordinate reference system.
* The given channel is not closed by this method, unless the {@code close} argument is set to
* {@code true}. The later case allows this method to close the channel sooner than what could
* be achieved if the channel was closed by the caller: before the WKT parsing begin.
*
* @param in The channel to read.
* @param close Whatever this method should close the channel.
* @return The PRJ file content as a coordinate reference system.
* @throws ContentFormatException If the content of the PRJ file is an invalid WKT.
* @throws IOException If the parsing failed for an other raison.
*
* @since 3.07
*/
public static CoordinateReferenceSystem read(final ReadableByteChannel in, final boolean close)
throws ContentFormatException, IOException
{
return read(Channels.newInputStream(in), close);
}
/**
* Parses a PRJ file from a stream and returns its content as a coordinate reference system.
* The given stream is not closed by this method, unless the {@code close} argument is set to
* {@code true}. The later case allows this method to close the stream sooner than what could
* be achieved if the stream was closed by the caller: before the WKT parsing begin.
*
* @param in The stream to read.
* @param close Whatever this method should close the stream.
* @return The PRJ file content as a coordinate reference system.
* @throws ContentFormatException If the content of the PRJ file is an invalid WKT.
* @throws IOException If the parsing failed for an other raison.
*/
public static CoordinateReferenceSystem read(final InputStream in, final boolean close)
throws ContentFormatException, IOException
{
return read(new BufferedReader(new InputStreamReader(in, ENCODING)), close);
}
/**
* Parses a PRJ file from a reader and returns its content as a coordinate reference system.
* The given reader is not closed by this method, unless the {@code close} argument is set to
* {@code true}. The later case allows this method to close the reader sooner than what could
* be achieved if the reader was closed by the caller: before the WKT parsing begin.
*
* @param in The reader.
* @param close Whatever this method should close the reader.
* @return The PRJ file content as a coordinate reference system.
* @throws ContentFormatException If the content of the PRJ file is an invalid WKT.
* @throws IOException If the parsing failed for an other raison.
*/
public static CoordinateReferenceSystem read(final BufferedReader in, final boolean close)
throws ContentFormatException, IOException
{
StringBuilder buffer = null;
String wkt=null, line;
while ((line = in.readLine()) != null) {
line = line.trim();
if (!line.isEmpty()) {
if (wkt == null) {
wkt = line;
} else {
if (buffer == null) {
buffer = new StringBuilder(wkt);
}
buffer.append('\n').append(line);
}
}
}
if (close) {
in.close();
}
if (buffer != null) {
wkt = buffer.toString();
}
if (wkt == null) {
throw new EOFException(Errors.format(Errors.Keys.END_OF_DATA_FILE));
}
try {
return CRS.parseWKT(wkt);
} catch (FactoryException e) {
throw new ContentFormatException(e.getLocalizedMessage(), e);
}
}
/**
* Formats the given CRS as a string.
*
* @throws ContentFormatException if the given CRS is not formattable as a WKT.
*/
private static String format(final CoordinateReferenceSystem crs) throws ContentFormatException {
try {
if (crs instanceof FormattableObject) {
return ((FormattableObject) crs).toWKT(Convention.OGC, WKTFormat.SINGLE_LINE);
} else {
return crs.toWKT();
}
} catch (UnsupportedOperationException e) {
throw new ContentFormatException(e.getLocalizedMessage(), e);
}
}
/**
* Formats a coordinate reference system as a PRJ file.
* The file is created only if the given CRS is formattable.
*
* @param crs The PRJ file content as a coordinate reference system.
* @param file The file to create. It usually has the {@code ".prj"} suffix,
* @throws ContentFormatException if the given CRS is not formattable as a WKT.
* @throws IOException If an other error occurred while writing the file.
*/
public static void write(final CoordinateReferenceSystem crs, final File file)
throws ContentFormatException, IOException
{
final String wkt = format(crs);
final Writer out = new OutputStreamWriter(new FileOutputStream(file), ENCODING);
// No need to buffer, because we will write everything (except EOL) in one shot.
// In addition, OutputStreamWriter already manage its own internal buffer anyway.
out.write(wkt);
out.write('\n'); // Use Unix EOL for cross-platform consistency.
out.close();
}
/**
* Formats a coordinate reference system as a PRJ file in the given channel. The channel
* is not closed by this method. It is caller responsibility to close it.
*
* @param crs The PRJ file content as a coordinate reference system.
* @param out The channel where to write.
* @throws ContentFormatException if the given CRS is not formattable as a WKT.
* @throws IOException If an other error occurred while writing the file.
*
* @since 3.07
*/
public static void write(final CoordinateReferenceSystem crs, final WritableByteChannel out)
throws ContentFormatException, IOException
{
write(crs, Channels.newOutputStream(out));
}
/**
* Formats a coordinate reference system as a PRJ file in the given stream. The stream
* is not closed by this method. It is caller responsibility to close it.
*
* @param crs The PRJ file content as a coordinate reference system.
* @param out The stream where to write.
* @throws ContentFormatException if the given CRS is not formattable as a WKT.
* @throws IOException If an other error occurred while writing the file.
*/
public static void write(final CoordinateReferenceSystem crs, final OutputStream out)
throws ContentFormatException, IOException
{
// No need to buffer - see the above method.
final Writer writer = new OutputStreamWriter(out, ENCODING);
write(crs, writer);
writer.flush();
}
/**
* Formats a coordinate reference system as a PRJ file in the given writer. The writer
* is not closed by this method. It is caller responsibility to close it.
*
* @param crs The PRJ file content as a coordinate reference system.
* @param out The writer.
* @throws ContentFormatException if the given CRS is not formattable as a WKT.
* @throws IOException If an other error occurred while writing the file.
*/
public static void write(final CoordinateReferenceSystem crs, final Writer out)
throws ContentFormatException, IOException
{
out.write(format(crs));
out.write('\n'); // Use Unix EOL for cross-platform consistency.
// No close - this is caller responsibility.
}
}