#13 solved: Exceptions, die nicht direkt behandelt werden können,

werden, bis auf wenige Ausnahmen, an die Main-Klasse weitergereicht, um
dort aufgefangen zu werden.
Die Software hat jetzt einen eigenen Logger und Util-Funktionen, für das
einfache Werfen von Fehlermeldungen.

.classpath

@@ -6,5 +6,6 @@
 	<classpathentry kind="lib" path="lib/mysql-connector-java-5.1.32-bin.jar"/>
 	<classpathentry kind="lib" path="lib/sqlite-jdbc-3.7.2.jar"/>
 	<classpathentry kind="lib" path="lib/swingx-all-1.6.4.jar"/>
+	<classpathentry kind="lib" path="lib/pdfbox-app-1.8.7.jar"/>
 	<classpathentry kind="output" path="bin"/>
 </classpath>

README.md

@@ -12,4 +12,7 @@ This software uses the Oracle MySQL Java Connector (http://dev.mysql.com/downloa
 
 ### Tango Desktop Project
 This software also uses icons provided by the Tango Desktop Project (http://tango.freedesktop.org/).
-License will follow!
+License will follow!
+
+### Apache PDFBox
+This software uses the Apache PDFBox (https://pdfbox.apache.org/) package which is published under Apache License v2.0 (http://www.apache.org/licenses/LICENSE-2.0);

src/de/katho/kBorrow/KLogger.java

@@ -0,0 +1,49 @@
+package de.katho.kBorrow;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.logging.FileHandler;
+import java.util.logging.Formatter;
+import java.util.logging.Handler;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.logging.SimpleFormatter;
+
+public class KLogger {
+	private static Logger logger;
+	private Handler fileHandler;
+	private Formatter plainText;
+	
+
+	private KLogger() throws IOException {
+		logger = Logger.getLogger(Util.class.getName());
+		String fDir = System.getProperty("user.home")+"/kBorrow";
+		String fName = "kBorrow.log";
+		File dir = new File(fDir);
+		File file = new File(fDir+"/"+fName);
+		
+		if(!dir.isDirectory()) dir.mkdir();
+		if(!file.isFile()) file.createNewFile();
+		
+		fileHandler = new FileHandler(fDir+"/"+fName, true);
+		plainText = new SimpleFormatter();
+		fileHandler.setFormatter(plainText);
+		logger.addHandler(fileHandler);
+	}
+	
+	private static Logger getLogger(){
+		if(logger == null){
+			try{
+				new KLogger();
+			} catch(IOException e){
+				Util.showError(e);
+			}
+		}
+		return logger;
+	}
+	
+	public static void log(Level pLevel, String pMsg, Exception e){
+		getLogger().log(pLevel, pMsg, e);
+		System.out.println(pMsg);
+	}
+}

src/de/katho/kBorrow/Settings.java

@@ -15,13 +15,13 @@ public class Settings {
 	private String filePath;
 	private String fileName;
 	
-	public Settings() {
-		this.properties = new Properties();
-		this.filePath = System.getProperty("user.home")+"/kBorrow";
-		this.fileName = "Settings.cfg";
+	public Settings() throws Exception {
+		properties = new Properties();
+		filePath = System.getProperty("user.home")+"/kBorrow";
+		fileName = "Settings.cfg";
 				
-		if(!this.filePathHasValidConfig()){
-			this.createDefaultConfig();
+		if(!filePathHasValidConfig()){
+			createDefaultConfig();
 		}
 	}
 	
@@ -31,14 +31,14 @@ public class Settings {
 	 */
 	private boolean filePathHasValidConfig(){
 		try {
-			InputStream in = new FileInputStream(this.filePath+"/"+this.fileName);
-			this.properties = new Properties();
+			InputStream in = new FileInputStream(filePath+"/"+fileName);
+			properties = new Properties();
 			
-			this.properties.load(in);
+			properties.load(in);
 			
 			// Check if the properties file holds certain keys and values.
-			if(		(this.properties.containsKey("dBType") && this.properties.containsValue("sqlite") && this.properties.containsKey("sqlitePath")) || 
-					(this.properties.contains("dbType") && this.properties.containsValue("mysql") && this.properties.containsKey("mysqlDB") && this.properties.containsKey("mysqlHost") && this.properties.containsKey("mysqlUser") && this.properties.containsKey("mysqlPass"))) {
+			if(		(properties.containsKey("dBType") && properties.containsValue("sqlite") && properties.containsKey("sqlitePath")) || 
+					(properties.contains("dbType") && properties.containsValue("mysql") && properties.containsKey("mysqlDB") && properties.containsKey("mysqlHost") && properties.containsKey("mysqlUser") && properties.containsKey("mysqlPass"))) {
 				in.close();
 				return true;
 				
@@ -49,21 +49,23 @@ public class Settings {
 			}
 				
 		} catch (FileNotFoundException e) {
+			Util.showWarning(new Exception("Kann die Settingsdatei nicht finden. Versuche, eine neue zu erzeugen.", e));
 			return false;
 		} catch (IOException e){
-			e.printStackTrace();
+			Util.showWarning(e);
 			return false;
 		}
 	}
 	
 	/**
 	 * Writes a default config to the config file.
+	 * @throws Exception 
 	 * 
 	 */
-	private void createDefaultConfig() {		
+	private void createDefaultConfig() throws Exception {		
 		try {
-			File dir = new File(this.filePath);
-			File file = new File(this.filePath+"/"+this.fileName);
+			File dir = new File(filePath);
+			File file = new File(filePath+"/"+fileName);
 			if(!dir.isDirectory()) dir.mkdir();
 			if(!file.isFile()) file.createNewFile();
 			else {
@@ -73,39 +75,40 @@ public class Settings {
 			
 			OutputStream os = new FileOutputStream(this.filePath+"/"+this.fileName);
 			
-			this.properties.put("dBType", "sqlite");
-			this.properties.put("sqlitePath",System.getProperty("user.home").replace("\\", "/")+"/kBorrow/kBorrow.db" );
-			this.properties.store(os, null);
+			properties.put("dBType", "sqlite");
+			properties.put("sqlitePath",System.getProperty("user.home").replace("\\", "/")+"/kBorrow/kBorrow.db" );
+			properties.store(os, null);
 			
 			os.close();
 		} catch (FileNotFoundException e) {
-			System.out.println("I couldn't find the specified properties file while trying to create a default config.");
-			e.printStackTrace();
+			throw new Exception("I couldn't find the specified properties file while trying to create a default config.", e);
 		} catch (IOException e) {
-			System.out.println("I had problems, writing to the properties file while trying to create a default config.");
-			e.printStackTrace();
+			throw new Exception("I had problems writing to the properties file while trying to create a default config.", e);
 		}		
 	}
 	
 	public String getProperty(String pKey){
-		return this.properties.getProperty(pKey);
+		if(properties.containsKey(pKey)) return properties.getProperty(pKey);
+		return "";
 	}
 	
-	public void setProperty(String pKey, String pValue){
-		this.properties.put(pKey, pValue);
+	public void setProperty(String pKey, String pValue) throws IOException{
+		properties.put(pKey, pValue);
 		
 		OutputStream os;
 		try {
 			os = new FileOutputStream(this.filePath+"/"+this.fileName);
-			this.properties.store(os, null);
+			properties.store(os, null);
 			
 			os.close();
 		} catch (FileNotFoundException e) {
-			System.out.println("I couldn't find the specified properties file while trying to write the config.");
-			e.printStackTrace();
+			throw new FileNotFoundException("I couldn't find the specified properties file while trying to write the config.");
 		} catch (IOException e) {
-			System.out.println("I had problems, writing to the properties file while saving a setting.");
-			e.printStackTrace();
+			throw new IOException("I had problems, writing to the properties file while saving a setting.");
 		}		
 	}
+	
+	public String getSettingsDir(){
+		return filePath;
+	}
 }

src/de/katho/kBorrow/Util.java

@@ -1,13 +1,52 @@
 package de.katho.kBorrow;
+
 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
 import java.util.Date;
+import java.util.Random;
+import java.util.logging.Level;
 
-public class Util {
+import javax.swing.JFrame;
+
+import org.jdesktop.swingx.JXErrorPane;
+import org.jdesktop.swingx.error.ErrorInfo;
+
+public final class Util {
+	private static JFrame mainwindow;
+	
 	public static String getCurrentDate(){
 		DateFormat dateFormat = new SimpleDateFormat("dd.MM.yyyy");
 		Date date = new Date();
 		
 		return dateFormat.format(date);
 	}
+	
+	public static String generateRandomString(int length) {
+		char[] chars = "abcdefghijklmnopqrstuvwxyz".toCharArray();
+		StringBuilder sb = new StringBuilder();
+		Random random = new Random();
+		
+		for (int i = 0; i < length; i++) {
+		    char c = chars[random.nextInt(chars.length)];
+		    sb.append(c);
+		}
+	
+		return sb.toString();
+	  }
+	
+	public static void showWarning(Exception e){
+		KLogger.log(Level.WARNING, e.getMessage(), e);
+		ErrorInfo info = new ErrorInfo("Warnung", e.getMessage(), null, null, e, Level.WARNING, null);
+		JXErrorPane.showDialog(mainwindow, info);
+	}
+	
+	public static void showError(Exception e){
+		KLogger.log(Level.SEVERE, e.getMessage(), e);
+		ErrorInfo info = new ErrorInfo("Fehler", e.getMessage(), null, null, e, Level.SEVERE, null);
+		JXErrorPane.showDialog(mainwindow, info);
+	}
+	
+	public static void setMainWindow(JFrame p){
+		mainwindow = p;
+	}
 }

src/de/katho/kBorrow/controller/NewLendingController.java

@@ -1,12 +1,28 @@
 package de.katho.kBorrow.controller;
 
+import org.apache.pdfbox.exceptions.COSVisitorException;
+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.apache.pdfbox.pdmodel.PDPage;
+import org.apache.pdfbox.pdmodel.common.PDRectangle;
+import org.apache.pdfbox.pdmodel.edit.PDPageContentStream;
+import org.apache.pdfbox.pdmodel.font.PDFont;
+import org.apache.pdfbox.pdmodel.font.PDType1Font;
+
+import java.awt.Desktop;
+import java.io.File;
+import java.io.IOException;
 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Date;
 import java.util.HashMap;
 
+import de.katho.kBorrow.Settings;
+import de.katho.kBorrow.Util;
+import de.katho.kBorrow.data.KArticle;
 import de.katho.kBorrow.data.KLender;
+import de.katho.kBorrow.data.KLending;
+import de.katho.kBorrow.data.KUser;
 import de.katho.kBorrow.db.DbConnector;
 import de.katho.kBorrow.models.ArticleTableModel;
 import de.katho.kBorrow.models.FreeArticleTableModel;
@@ -21,14 +37,16 @@ public class NewLendingController {
 	private FreeArticleTableModel freeArticleModel;
 	private LendingTableModel lendingTableModel;
 	private ArticleTableModel articleTableModel;
+	private Settings settings;
 	
-	public NewLendingController(DbConnector pDbCon, HashMap<String, Object> pModels){
+	public NewLendingController(DbConnector pDbCon, HashMap<String, Object> pModels, final Settings pSettings){
 		dbCon = pDbCon;
 		userListModel = (UserListModel)pModels.get("userlistmodel");
 		lenderModel = (LenderModel)pModels.get("lendermodel");
 		freeArticleModel = (FreeArticleTableModel)pModels.get("freearticletablemodel");
 		articleTableModel = (ArticleTableModel)pModels.get("articletablemodel");
 		lendingTableModel = (LendingTableModel)pModels.get("lendingtablemodel");
+		settings = pSettings;
 	}
 	
 	/**
@@ -41,8 +59,9 @@ public class NewLendingController {
 	 * 				4:		Die gegebene Kombination aus Lender-Name, -Surname und -Studentnumber
 	 * 						existiert mehrmals in der Datenbank. Das darf nicht sein und wirft daher einen Fehler!
 	 * 				5:		Matrikelnummer muss eine Zahl sein!
+	 * @throws Exception 
 	 */
-	public int newLending(int pArtId, String pLName, String pLSurname, String pLSN, String pStartDate, Date pEstEndDate, String pUsername){
+	public int newLending(int pArtId, String pLName, String pLSurname, String pLSN, String pStartDate, Date pEstEndDate, String pUsername) throws Exception{
 		if(pArtId == -1 || pStartDate.isEmpty() || pEstEndDate == null || pLName.isEmpty() || pLSurname.isEmpty() || pUsername.isEmpty()) return 2;
 		if(pEstEndDate.before(new Date())) return 3;
 		if(!pLSN.matches("[0-9]+")) return 5;
@@ -62,16 +81,114 @@ public class NewLendingController {
 			KLender lender = lenders.get(0);
 			int uId = userListModel.getIdByFullname(pUsername);
 			DateFormat dateFormat = new SimpleDateFormat("dd.MM.yyyy");
-			int result = dbCon.createNewLending(pArtId, uId, lender.getId(), pStartDate, dateFormat.format(pEstEndDate));
 			
-			if(result == 0){
+			int[] result = dbCon.createNewLending(pArtId, uId, lender.getId(), pStartDate, dateFormat.format(pEstEndDate));
+			
+			if(result[0] == 0){
 				freeArticleModel.updateModel();
 				articleTableModel.updateModel();
 				lendingTableModel.updateModel();
-				return result;
+				createPdfFile(result[1]);
+				
+				return result[0];
 			}
-			else return result;
+			else return result[0];
 		}
 		return 4;
 	}
+	
+	
+	private void createPdfFile(int pLendingId) throws Exception {
+		KLending lending = lendingTableModel.getLendingById(pLendingId);
+		KArticle article = articleTableModel.getArticleById(lending.getArticleId());
+		KUser user = userListModel.getUserById(lending.getUserId());
+		KLender lender = lenderModel.getLenderById(lending.getLenderId());		
+		
+		PDDocument doc = new PDDocument();
+		PDPage page = new PDPage(PDPage.PAGE_SIZE_A4);
+		PDRectangle rect = page.getMediaBox();
+		doc.addPage(page);
+		
+		PDFont fontNormal = PDType1Font.HELVETICA;
+		PDFont fontBold = PDType1Font.HELVETICA_BOLD;
+		
+		String[] text = {
+							"Artikel: ",
+							"Verliehen von: ",
+							"Ausgeliehen an: ",
+							"Start der Ausleihe: ",
+							"Voraussichtliche R<>ckgabe: "
+						};
+		String[] vars = {
+							article.getName(),
+							user.getName()+" "+user.getSurname(),
+							lender.getName()+" "+lender.getSurname()+" ("+lender.getStudentnumber()+")",
+							lending.getStartDate(),
+							lending.getExpectedEndDate()
+						};
+		try {
+			File file = createRandomFile();
+			
+			PDPageContentStream cos = new PDPageContentStream(doc, page);
+			
+			cos.beginText();
+			cos.moveTextPositionByAmount(100, rect.getHeight() - 100);
+			cos.setFont(fontBold, 16);
+			cos.drawString("Ausleihe #"+lending.getId());
+			cos.endText();
+			
+			int i = 0;
+			
+			while (i < text.length){
+				cos.beginText();
+				cos.moveTextPositionByAmount(100, rect.getHeight() - 25*(i+2) - 100 );
+				cos.setFont(fontBold, 12);
+				cos.drawString(text[i]);
+				cos.moveTextPositionByAmount(rect.getWidth() / 2 - 100, 0);
+				cos.setFont(fontNormal, 12);
+				cos.drawString(vars[i]);
+				cos.endText();
+				i++;
+			}
+			
+			i = i+2;
+			cos.setLineWidth(1);
+			cos.addLine(100, rect.getHeight() - 25*(i+2) - 100, 300, rect.getHeight() - 25*(i+2) - 100);
+			cos.closeAndStroke();
+			
+			i++;
+			
+			cos.beginText();
+			cos.moveTextPositionByAmount(100, rect.getHeight() - 25*(i+2) - 100);
+			cos.setFont(fontNormal, 12);
+			cos.drawString("Unterschrift "+lender.getName()+" "+lender.getSurname());
+			cos.endText();			
+		
+			cos.close();
+			doc.save(file);
+			doc.close();
+			
+			if(Desktop.isDesktopSupported()){
+				Desktop desktop = Desktop.getDesktop();
+				if(desktop.isSupported(Desktop.Action.OPEN)){
+					desktop.open(file);
+				}
+			}
+		} catch (IOException | COSVisitorException e) {
+			throw new Exception("Problem bei der Erstellung der PDF-Datei.", e);
+		}
+	}
+	
+	private File createRandomFile() throws IOException{
+		File dir = new File(settings.getSettingsDir()+"/tmp");
+		File file = new File(settings.getSettingsDir()+"/tmp/"+Util.generateRandomString(8)+".pdf");
+		if(!dir.isDirectory()) dir.mkdir();
+		if(!file.isFile()) file.createNewFile();
+		else {
+			file.delete();
+			file.createNewFile();
+		}
+		
+		return file;
+	}
 }

src/de/katho/kBorrow/data/KArticle.java

@@ -7,22 +7,22 @@ public class KArticle {
 	private boolean isFree;
 
 	public KArticle(int pId, String pName, boolean pFree, String pDesc) {
-		this.id = pId;
-		this.name = pName;
-		this.description = pDesc;
+		id = pId;
+		name = pName;
+		description = pDesc;
 		isFree = pFree;
 	}
 
 	public int getId() {
-		return this.id;
+		return id;
 	}
 
 	public String getName() {
-		return this.name;
+		return name;
 	}
 
 	public String getDescription() {
-		return this.description;
+		return description;
 	}
 	
 	public boolean getIsFree(){
@@ -30,11 +30,11 @@ public class KArticle {
 	}
 	
 	public void setName(String pName){
-		this.name = pName;
+		name = pName;
 	}
 	
 	public void setDescription(String pDesc){
-		this.description = pDesc;
+		description = pDesc;
 	}
 	
 	public void setIsFree(boolean pFree){

src/de/katho/kBorrow/db/DbConnector.java

@@ -19,7 +19,7 @@ public interface DbConnector {
 	public int editArticle(int pId, String pName, String pDesc);
 	public ArrayList<KArticle> getFreeArticleList();
 	public ArrayList<KLender> getLenderList();
-	public int createNewLending(int pArtId, int pUId, int pLId, String pStartDate, String pEstEndDate);
+	public int[] createNewLending(int pArtId, int pUId, int pLId, String pStartDate, String pEstEndDate);
 	public int createNewLender(String pLName, String pLSurname, String pLSN);
 	public ArrayList<KLending> getActiveLendingList();
 	public int returnLending(int lendingId, int artId, String string);

src/de/katho/kBorrow/db/SqlConnector.java

@@ -75,10 +75,10 @@ public class SqlConnector implements DbConnector{
 	}
 
 	@Override
-	public int createNewLending(int pArtId, int pUId, int pLId,
+	public int[] createNewLending(int pArtId, int pUId, int pLId,
 			String pStartDate, String pEstEndDate) {
 		// TODO Auto-generated method stub
-		return 0;
+		return new int[2];
 	}
 
 	@Override

src/de/katho/kBorrow/db/SqliteConnector.java

@@ -12,6 +12,7 @@ import java.util.ArrayList;
 import java.util.Hashtable;
 import java.util.Map.Entry;
 
+import de.katho.kBorrow.Util;
 import de.katho.kBorrow.data.KArticle;
 import de.katho.kBorrow.data.KLender;
 import de.katho.kBorrow.data.KLending;
@@ -92,7 +93,7 @@ public class SqliteConnector implements DbConnector {
 			return true;
 			
 		} catch (SQLException e) {
-			e.printStackTrace();
+			Util.showWarning(e);
 			return false;
 		}		
 	}
@@ -108,7 +109,7 @@ public class SqliteConnector implements DbConnector {
 			return true;
 		}
 		catch (SQLException e){
-			e.printStackTrace();
+			Util.showWarning(e);
 			return false;
 		}
 	}
@@ -201,7 +202,7 @@ public class SqliteConnector implements DbConnector {
 			return userArr;
 		} 
 		catch (SQLException e){
-			e.printStackTrace();
+			Util.showWarning(e);
 			return null;
 		}
 	}
@@ -221,7 +222,7 @@ public class SqliteConnector implements DbConnector {
 			return userArr;
 		} 
 		catch (SQLException e){
-			e.printStackTrace();
+			Util.showWarning(e);
 			return null;
 		}
 	}
@@ -241,7 +242,7 @@ public class SqliteConnector implements DbConnector {
 			return artArr;
 		}
 		catch (SQLException ex){
-			ex.printStackTrace();
+			Util.showWarning(ex);
 			return null;
 		}
 	}
@@ -261,7 +262,7 @@ public class SqliteConnector implements DbConnector {
 			return artArr;
 		}
 		catch(SQLException ex){
-			ex.printStackTrace();
+			Util.showWarning(ex);
 			return null;
 		}
 	}
@@ -281,7 +282,7 @@ public class SqliteConnector implements DbConnector {
 			return lendArr;
 		}
 		catch(SQLException ex){
-			ex.printStackTrace();
+			Util.showWarning(ex);
 			return null;
 		}
 	}
@@ -302,7 +303,7 @@ public class SqliteConnector implements DbConnector {
 			return lendingArr;
 		}
 		catch(SQLException e){
-			e.printStackTrace();
+			Util.showWarning(e);
 			return lendingArr;
 		}
 	}
@@ -323,7 +324,7 @@ public class SqliteConnector implements DbConnector {
 			return lendingArr;
 		}
 		catch(SQLException e){
-			e.printStackTrace();
+			Util.showWarning(e);
 			return lendingArr;
 		}
 	}
@@ -345,7 +346,7 @@ public class SqliteConnector implements DbConnector {
 			return 0;
 			
 		} catch (SQLException e) {
-			e.printStackTrace();
+			Util.showWarning(e);
 			return 1;
 		}
 	}
@@ -361,7 +362,7 @@ public class SqliteConnector implements DbConnector {
 			return 0;
 		}
 		catch(SQLException e){
-			e.printStackTrace();
+			Util.showWarning(e);
 			return 1;
 		}
 	}
@@ -377,7 +378,7 @@ public class SqliteConnector implements DbConnector {
 			return true;
 		}
 		catch (SQLException e){
-			e.printStackTrace();
+			Util.showWarning(e);
 			return false;
 		}
 	}
@@ -393,7 +394,7 @@ public class SqliteConnector implements DbConnector {
 			return 0;
 			
 		} catch (SQLException e) {
-			e.printStackTrace();
+			Util.showWarning(e);
 			return 1;
 		}
 	}
@@ -408,7 +409,7 @@ public class SqliteConnector implements DbConnector {
 			return 0;
 		}
 		catch (SQLException e){
-			e.printStackTrace();
+			Util.showWarning(e);
 			return 1;
 		}
 	}
@@ -424,31 +425,46 @@ public class SqliteConnector implements DbConnector {
 			return 0;
 		}
 		catch(SQLException e){
-			e.printStackTrace();
+			Util.showWarning(e);
 			return 1;
 		}
 	}
 
 	/**
+	 * Erstellt eine neue Ausleihe.
 	 * 
-	 * @return	Status-Code:
-	 * 			0:		Erfolg
-	 * 			1:		SQL-Fehler
+	 * 
+	 * @return	R<>ckgabewert ist ein Array mit zwei Werten.
+	 * 
+	 * 			Index		0:	Enth<74>lt den R<>ckgabestatus:
+	 * 			- Status 	0:	Alles in Ordnung
+	 * 			- Status	1:	SQL-Fehler
+	 * 
+	 * 			Index 1: Enth<74>lt die ID der gerade erzeugten Tabellenzeile
 	 */
-	public int createNewLending(int pArtId, int pUId, int pLId, String pStartDate, String pEstEndDate) {
+	public int[] createNewLending(int pArtId, int pUId, int pLId, String pStartDate, String pEstEndDate) {
+		int[] result = new int[2];
+		
 		try{
 			Statement st = connection.createStatement();
 			String query = "INSERT INTO lending (article_id, user_id, lender_id, start_date, expected_end_date ) "
-					+ "VALUES ("+pArtId+", "+pUId+", "+pLId+", '"+pStartDate+"', '"+pEstEndDate+"');"
+							+ "VALUES ("+pArtId+", "+pUId+", "+pLId+", '"+pStartDate+"', '"+pEstEndDate+"');"
 							+ "UPDATE article SET is_free = 0 WHERE id = "+pArtId+";";
 			
 			st.executeUpdate(query);
 			
-			return 0;
+			query = "SELECT id FROM lending ORDER BY id DESC LIMIT 1;";
+			
+			ResultSet rs = st.executeQuery(query);
+			
+			result[1] = rs.getInt("id");
+			result[0] = 0;
+			
+			return result;
 		}
 		catch(SQLException e){
-			e.printStackTrace();
-			return 1;
+			Util.showWarning(e);
+			return new int[]{1,0};
 		}
 	}
 
@@ -462,7 +478,7 @@ public class SqliteConnector implements DbConnector {
 			return true;
 		}
 		catch(SQLException e){
-			e.printStackTrace();
+			Util.showWarning(e);
 			return false;
 		}
 	}
@@ -478,7 +494,7 @@ public class SqliteConnector implements DbConnector {
 			return 0;
 		}
 		catch(SQLException e){
-			e.printStackTrace();
+			Util.showWarning(e);
 			return 1;
 		}
 		
@@ -495,7 +511,7 @@ public class SqliteConnector implements DbConnector {
 			return 0;
 		}
 		catch(SQLException e){
-			e.printStackTrace();
+			Util.showWarning(e);
 			return 1;
 		}
 	}

src/de/katho/kBorrow/gui/MainWindow.java

@@ -5,16 +5,13 @@ import javax.swing.JTabbedPane;
 import javax.swing.UIManager;
 import javax.swing.UnsupportedLookAndFeelException;
 
-import org.jdesktop.swingx.JXErrorPane;
-import org.jdesktop.swingx.error.ErrorInfo;
-
-
 import java.awt.BorderLayout;
+import java.io.File;
 import java.io.IOException;
-import java.sql.SQLException;
 import java.util.HashMap;
 
 import de.katho.kBorrow.Settings;
+import de.katho.kBorrow.Util;
 import de.katho.kBorrow.db.DbConnector;
 import de.katho.kBorrow.db.SqlConnector;
 import de.katho.kBorrow.db.SqliteConnector;
@@ -46,14 +43,25 @@ public class MainWindow {
 	 * @throws ClassNotFoundException 
 	 * @throws IOException 
 	 */
-	public MainWindow() throws IOException {
-		set = new Settings();
-		frame = new JFrame();
-		frame.setResizable(false);
-		frame.setBounds(100, 100, 600, 500);
-		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+	public MainWindow() {
+		// Delete all files in tmp-dir
+		Runtime.getRuntime().addShutdownHook(new Thread(){
+			public void run(){
+				File dir = new File(set.getSettingsDir()+"/tmp/");
+				if(dir.isDirectory()){
+					for(File file : dir.listFiles()) file.delete();
+				}
+			}
+		});
 		
 		try {
+			frame = new JFrame();
+			frame.setResizable(false);
+			frame.setBounds(100, 100, 600, 500);
+			frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+			Util.setMainWindow(frame);
+			set = new Settings();
+			
 			UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
 			
 			if(set.getProperty("dBType").equals("sqlite")){
@@ -72,23 +80,22 @@ public class MainWindow {
 			models.put("lendingtablemodel", new LendingTableModel(dbCon, models));
 			
 			tabbedPane = new JTabbedPane(JTabbedPane.TOP);
-			frame.getContentPane().add(this.tabbedPane, BorderLayout.CENTER);
-			tabbedPane.addTab("Neue Ausleihe", new NewLendingPanel(this.dbCon, models));
+			frame.getContentPane().add(tabbedPane, BorderLayout.CENTER);
+			tabbedPane.addTab("Neue Ausleihe", new NewLendingPanel(this.dbCon, models, set));
 			tabbedPane.addTab("Ausleihen verwalten", new ManageLendingsPanel(this.dbCon, models));
 			tabbedPane.addTab("Artikel verwalten", new ArticlePanel(this.dbCon, models));
 			tabbedPane.addTab("Benutzer verwalten", new UserPanel(this.dbCon, models));
 			
 		}
-		catch(ClassNotFoundException | InstantiationException | IllegalAccessException | IOException | UnsupportedLookAndFeelException | SQLException e) {
-			ErrorInfo info = new ErrorInfo("Exception", e.getMessage(), null, null, e, null, null);
-			JXErrorPane.showDialog(frame, info);
+		catch(Exception e) {
+			Util.showError(e);
 			System.exit(1);
 		}
 		
-		this.frame.setVisible(true);
+		frame.setVisible(true);
 	}
 	
-	public static void main(String[] args) throws IOException{
+	public static void main(String[] args) {
 		new MainWindow();
 	}
 }

src/de/katho/kBorrow/gui/NewLendingPanel.java

@@ -28,6 +28,7 @@ import javax.swing.border.TitledBorder;
 import org.jdesktop.swingx.JXDatePicker;
 import org.jdesktop.swingx.autocomplete.AutoCompleteDecorator;
 
+import de.katho.kBorrow.Settings;
 import de.katho.kBorrow.Util;
 import de.katho.kBorrow.controller.NewLendingController;
 import de.katho.kBorrow.converter.LenderNameConverter;
@@ -70,7 +71,7 @@ public class NewLendingPanel extends JPanel implements ActionListener, FocusList
 	 * @param dbCon 
 	 * @throws IOException 
 	 */
-	public NewLendingPanel(final DbConnector dbCon, HashMap<String, Object> pModel) throws IOException {
+	public NewLendingPanel(final DbConnector dbCon, HashMap<String, Object> pModel, final Settings pSettings) throws IOException {
 		setLayout(null);
 		articleId = -1;
 		
@@ -78,7 +79,7 @@ public class NewLendingPanel extends JPanel implements ActionListener, FocusList
 		freeArticleTableModel = (FreeArticleTableModel)pModel.get("freearticletablemodel");
 		userListModel = (UserListModel)pModel.get("userlistmodel");
 		lenderModel = (LenderModel)pModel.get("lendermodel");
-		newLendingController = new NewLendingController(dbCon, pModel);
+		newLendingController = new NewLendingController(dbCon, pModel, pSettings);
 		
 		JTable freeArticleTable = new JTable(freeArticleTableModel);
 		freeArticleTable.setRowHeight(30);
@@ -217,7 +218,7 @@ public class NewLendingPanel extends JPanel implements ActionListener, FocusList
 		tfStudentNumber.setText("");
 	}
 	
-	private void saveButtonPressed(){
+	private void saveButtonPressed() throws Exception {
 		String pLName = tfName.getText();
 		String pLSurname = tfSurname.getText();
 		String startDate = lblStartDate.getText();
@@ -266,7 +267,11 @@ public class NewLendingPanel extends JPanel implements ActionListener, FocusList
 		}
 		
 		if(pEvent.getSource() == btnSave){
-			saveButtonPressed();
+			try {
+				saveButtonPressed();
+			} catch (Exception e) {
+				Util.showError(e);
+			}
 		}
 		
 	}
@@ -287,7 +292,12 @@ public class NewLendingPanel extends JPanel implements ActionListener, FocusList
 	}
 
 	public void keyPressed(KeyEvent pKeyPress) {
-		if(pKeyPress.getKeyCode() == KeyEvent.VK_ENTER) saveButtonPressed();
+		if(pKeyPress.getKeyCode() == KeyEvent.VK_ENTER)
+			try {
+				saveButtonPressed();
+			} catch (Exception e) {
+				Util.showError(e);
+			}
 		
 	}
 

src/de/katho/kBorrow/models/UserListModel.java

@@ -72,6 +72,13 @@ public class UserListModel extends AbstractListModel<String> implements ComboBox
 		return -1;
 	}
 	
+	public KUser getUserById(int pId){
+		for (KUser elem : data){
+			if(elem.getId() == pId) return elem;
+		}
+		return null;
+	}
+	
 	
 }