implemented test for database export

tests/de/deadlocker8/budgetmaster/tests/resources/export.json

-{  "categories": [    {      "ID": 1,      "name": "NONE",      "color": {        "red": 1.0,        "green": 1.0,        "blue": 1.0,        "opacity": 1.0      }    },    {      "ID": 2,      "name": "Übertrag",      "color": {        "red": 1.0,        "green": 1.0,        "blue": 0.0,        "opacity": 1.0      }    },    {      "ID": 3,      "name": "123 Tü+?est Category",      "color": {        "red": 0.9411765,        "green": 0.972549,        "blue": 1.0,        "opacity": 1.0      }    }  ],  "normalPayments": [    {      "ID": 1,      "amount": 23,      "date": "2017-06-02",      "categoryID": 0,      "name": "Test Normal",      "description": "Lorem Ipsum"    }  ],  "repeatingPayments": [    {      "repeatInterval": 7,      "repeatEndDate": "2017-06-30",      "repeatMonthDay": 0,      "ID": 3,      "amount": -10012,      "date": "2017-06-01",      "categoryID": 1,      "name": "Test Repeating",      "description": "Lorem Ipsum"    }  ]}
\ No newline at end of file
+{"categories":[{"ID":2,"name":"Übertrag","color":{"red":1.0,"green":1.0,"blue":0.0,"opacity":1.0}},{"ID":3,"name":"123 Tü+?est Category","color":{"red":0.9411765,"green":0.972549,"blue":1.0,"opacity":1.0}},{"ID":4,"name":"123 Tü+?est Category","color":{"red":0.9411765,"green":0.972549,"blue":1.0,"opacity":1.0}}],"normalPayments":[],"repeatingPayments":[]}
\ No newline at end of file

tests/de/deadlocker8/budgetmaster/tests/resources/import.json

+{"categories":[{"ID":1,"name":"NONE","color":{"red":1.0,"green":1.0,"blue":1.0,"opacity":1.0}},{"ID":2,"name":"Übertrag","color":{"red":1.0,"green":1.0,"blue":0.0,"opacity":1.0}},{"ID":3,"name":"123 Tü+?est Category","color":{"red":0.9411765,"green":0.972549,"blue":1.0,"opacity":1.0}}],"normalPayments":[{"ID":1,"amount":23,"date":"2017-06-02","categoryID":0,"name":"Test Normal","description":"Lorem Ipsum"}],"repeatingPayments":[{"repeatInterval":7,"repeatEndDate":"2017-06-30","repeatMonthDay":0,"ID":1,"amount":-10012,"date":"2017-06-01","categoryID":1,"name":"Test Repeating","description":"Lorem Ipsum"}]}
\ No newline at end of file

tests/de/deadlocker8/budgetmaster/tests/server/database/DatabaseExportTest.java

+package de.deadlocker8.budgetmaster.tests.server.database;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import com.google.gson.Gson;
+
+import de.deadlocker8.budgetmasterserver.logic.DatabaseExporter;
+import de.deadlocker8.budgetmasterserver.logic.Settings;
+import de.deadlocker8.budgetmasterserver.logic.Utils;
+
+public class DatabaseExportTest
+{			
+	private static Settings settings; 
+	
+	@BeforeClass
+	public static void init()
+	{
+		try
+		{
+			//init
+			settings = Utils.loadSettings();	
+		}
+		catch(IOException | URISyntaxException e)
+		{
+			fail(e.getMessage());
+		}		
+	}	
+	
+	@Test
+	public void testExport()
+	{	
+		try
+		{
+			File file = Paths.get("tests/de/deadlocker8/budgetmaster/tests/resources/export.json").toFile();
+			DatabaseExporter exporter = new DatabaseExporter(settings);	
+			Gson gson = new Gson();
+			String databaseJSON = gson.toJson(exporter.exportDatabase());
+			de.deadlocker8.budgetmaster.logic.Utils.saveDatabaseJSON(file, databaseJSON);		
+			
+			String expectedJSON = new String(Files.readAllBytes(Paths.get("tests/de/deadlocker8/budgetmaster/tests/resources/import.json")));
+			String exportedJSON = new String(Files.readAllBytes(Paths.get("tests/de/deadlocker8/budgetmaster/tests/resources/export.json")));
+			assertEquals(expectedJSON, exportedJSON);
+		}
+		catch(Exception e)
+		{
+			e.printStackTrace();
+			fail(e.getMessage());
+		}		
+	}
+}
\ No newline at end of file

tests/de/deadlocker8/budgetmaster/tests/server/database/DatabaseImportTest.java

@@ -49,7 +49,7 @@ public class DatabaseImportTest
 	{	
 		try
 		{
-			File file = Paths.get("tests/de/deadlocker8/budgetmaster/tests/resources/export.json").toFile();
+			File file = Paths.get("tests/de/deadlocker8/budgetmaster/tests/resources/import.json").toFile();
 			Database database = de.deadlocker8.budgetmaster.logic.Utils.loadDatabaseJSON(file);			
 			
 			DatabaseImporter importer = new DatabaseImporter(databaseHandler);