Update test and writer

From the test class the whenReadWithBufferedReader_thenCorrect() and testCPGFileCreation() have been removed and a new method testCpgFileAgainstRelatedSpapefile() called from all the Test methods.
The writer has been updated taking the charset from the ShapefileDataStore of the related shapefile or adding the default charset in case the above one is null

feat: extend shapefile writer to create .cpg file

Create .cpg file/files when one/more .shp files are created.
The .cpg file contain only the encoding used to write the shapefile.
Create test for creating .cpg file

io/plugins/eu.esdihumboldt.hale.io.shp.test/src/eu/esdihumboldt/hale/io/shp/ShapefileInstanceWriterTest.groovy

@@ -25,6 +25,7 @@ import java.time.Instant
 import java.time.LocalDate
 import java.util.function.Consumer
 
+import org.geotools.data.shapefile.ShapefileDataStore
 import org.junit.Test
 import org.locationtech.jts.geom.Coordinate
 import org.locationtech.jts.geom.Geometry
@@ -100,7 +101,7 @@ class ShapefileInstanceWriterTest {
 		String filenameOnly = Paths.get(location).getFileName().toString();
 
 		filenameOnly = filenameOnly.substring(0, filenameOnly.lastIndexOf("."));
-		String filename = filePath + "/" + filenameOnly + "_" + additionalName + ".shp";
+		String filename = filePath + "/" + filenameOnly + "_" + additionalName + ShapefileConstants.SHP_EXTENSION;
 		file = new File(filename)
 		Schema schema = loadSchema(file)
 
@@ -114,10 +115,11 @@ class ShapefileInstanceWriterTest {
 		assertTrue(report.isSuccess())
 		assertTrue(report.getErrors().isEmpty())
 
+		testCpgFileAgainstRelatedSpapefile(file)
+
 		return reader.getInstances();
 	}
 
-
 	/**
 	 * Write an instance collection to a Shapefile.
 	 */
@@ -184,11 +186,25 @@ class ShapefileInstanceWriterTest {
 			println "Temporary file is $tmpFile"
 			writeInstances(tmpFile.toFile(), schema, instances, configurator)
 			handler.accept(tmpFile.toFile())
+
+			testCpgFileAgainstRelatedSpapefile(tmpFile.toFile())
 		} finally {
 			tmpDir.deleteDir()
 		}
 	}
 
+	private static testCpgFileAgainstRelatedSpapefile(File shpFile) {
+		ShapefileDataStore store = new ShapefileDataStore(shpFile.toURL());
+		String cpgFilePath = shpFile.getAbsolutePath().replace(ShapefileConstants.SHP_EXTENSION, ShapefileConstants.CPG_EXTENSION)
+
+		def cpgFile = new File(cpgFilePath)
+		if (cpgFile.exists()) {
+			assertTrue(store.getCharset().toString().equals(cpgFile.text))
+		} else {
+			println("File not found.")
+		}
+	}
+
 	//@CompileStatic
 	static void withNewShapefileWithReporterErrors(Schema schema, InstanceCollection instances, Consumer<File> handler,
 			Consumer<ShapefileInstanceWriter> configurator = null) {
@@ -199,6 +215,8 @@ class ShapefileInstanceWriterTest {
 			println "Temporary file is $tmpFile"
 			writeInstancesWithReporterErrors(tmpFile.toFile(), schema, instances, configurator)
 			handler.accept(tmpFile.toFile())
+
+			testCpgFileAgainstRelatedSpapefile(tmpFile.toFile())
 		} finally {
 			tmpDir.deleteDir()
 		}
@@ -240,6 +258,7 @@ class ShapefileInstanceWriterTest {
 					num++
 				}
 			}
+
 			// 593 instances were loaded
 			assertEquals(593, num)
 		}

io/plugins/eu.esdihumboldt.hale.io.shp/src/eu/esdihumboldt/hale/io/shp/ShapefileConstants.java

@@ -81,6 +81,12 @@ public interface ShapefileConstants {
 	 * Constant for the shape file extension.
 	 */
 	public static final String SHP_EXTENSION = ".shp";
+
+	/**
+	 * Constant for the CPG file extension.
+	 */
+	public static final String CPG_EXTENSION = ".cpg";
+
 	/**
 	 * Constant for underscore.
 	 */

io/plugins/eu.esdihumboldt.hale.io.shp/src/eu/esdihumboldt/hale/io/shp/writer/ShapefileInstanceWriter.java

@@ -16,6 +16,7 @@
 package eu.esdihumboldt.hale.io.shp.writer;
 
 import java.io.File;
+import java.io.FileWriter;
 import java.io.IOException;
 import java.io.Serializable;
 import java.net.URI;
@@ -122,6 +123,11 @@ protected IOReport execute(ProgressIndicator progress, IOReporter reporter)
 				setTarget(new MultiLocationOutputSupplier(uris));
 			}
 
+			for (String f : filesWritten) {
+				String cpgFileName = filePath + "/" + f + ShapefileConstants.CPG_EXTENSION;
+				writeCodePageFile(cpgFileName);
+			}
+
 			reporter.setSuccess(true);
 		} catch (Exception e) {
 			reporter.error(new IOMessageImpl(e.getMessage(), e));
@@ -724,4 +730,35 @@ private List<String> writeToFile(
 		return filesWritten;
 	}
 
+	/**
+	 * Create the CPG file starting from the Shapefile
+	 * 
+	 * @param cpgFilePath Path of the file to be written with just one line of
+	 *            the encoding
+	 * @throws IOException exception in any.
+	 */
+	public void writeCodePageFile(String cpgFilePath) throws IOException {
+		File cpgFile = new File(cpgFilePath);
+		FileWriter fileWriter = new FileWriter(cpgFile);
+
+		ShapefileDataStore store = new ShapefileDataStore(
+				new File(cpgFilePath.replace(ShapefileConstants.CPG_EXTENSION,
+						ShapefileConstants.SHP_EXTENSION)).toURL());
+
+		try {
+			fileWriter.write(store.getCharset() != null ? store.getCharset().toString()
+					: getDefaultCharset().toString());
+		} catch (IOException e) {
+			throw new IOException("An error occurred while writing the CPG file: " + cpgFilePath
+					+ " " + e.getMessage());
+		} finally {
+			try {
+				fileWriter.close();
+			} catch (IOException e) {
+				throw new IOException("An error occurred while trying to close the CPG file: "
+						+ cpgFilePath + " " + e.getMessage());
+			}
+		}
+	}
+
 }