Problema com PreparedStatement no HSQLDB

import java.io.*;
import java.sql.*; 
import java.util.ArrayList;

import javax.swing.*;

public class DBLayer {
	private static DBLayer instance;
	private Connection con;
	private Statement stm;
//	private PreparedStatement pstm;
	private MyProperties properties = MyProperties.getInstance();
	private String
		driver = properties.getProperty("DB_DRIVER"),
		url = properties.getProperty("DB_URL"),
		user = properties.getProperty("DB_USER"),
		password = properties.getProperty("DB_PASSWORD"),
		path = properties.getProperty("MUSIC_DIRECTORY"),
		dbHome = properties.getProperty("DB_HOME");
	
	private DBLayer() {}
	
	public static DBLayer getInstance() {
		if (instance == null) {
			instance = new DBLayer();
		}
		return instance;
	}
	
	public ArrayList<Object[]> getTableData(String sql) {
		ArrayList<Object[]> array = new ArrayList<Object[]>();
		try {
			Class.forName(driver);
			con = DriverManager.getConnection(url, user, password);
			stm = con.createStatement();
			ResultSet rs = stm.executeQuery(sql);
			ResultSetMetaData rsmd = rs.getMetaData();
			while(rs.next()) {
				Object[] o = new Object[rsmd.getColumnCount()];
				for(int i = 0; i < o.length; i++) {
					o[i] = rs.getObject(i + 1).toString();
				}
				array.add(o);
			}
		} catch (SQLException e) {
			JOptionPane.showMessageDialog(null, "Excessão SQL em getStyleData");
			e.printStackTrace();
		} catch (ClassNotFoundException e) {
			JOptionPane.showMessageDialog(null, "ClassNotFoundException em getStyleData");
			e.printStackTrace();
		}
		return array;
	}
	
	public void insertDB() {
		
		String insertStyle = properties.getProperty("INSERT_STYLE");
		String insertArtist = properties.getProperty("INSERT_ARTIST");
		String insertAlbum = properties.getProperty("INSERT_ALBUM");
		String insertTitle = properties.getProperty("INSERT_TITLE");
		String updateStyle = properties.getProperty("UPDATE_STYLE");
		String updateArtist = properties.getProperty("UPDATE_ARTIST");
		String updateAlbum = properties.getProperty("UPDATE_ALBUM");
		
		int iArtist = -1;
		int iAlbum = -1;
		int iTitle = -1;
		try {
			con = DriverManager.getConnection(url, user, password);

			File musicDir = new File(path);
			String[] styles = musicDir.list();
			
			for(int i = 0; i < styles.length; i++) {
				File stylesDir = new File(musicDir + File.separator + styles[i]);

				if(stylesDir.isDirectory()) {
					PreparedStatement pstm0 = con.prepareStatement(insertStyle);
					pstm0.setInt(1, i);
					pstm0.setString(2, styles[i]);
					pstm0.executeUpdate();
					pstm0.close();
					//primeiro JOptionPane
					JOptionPane.showMessageDialog(null, stylesDir.getAbsoluteFile() + " " + i
							+ "\n" + insertStyle + " " + i + " " + styles[i]);
					String[] artists = stylesDir.list();
					for(int j = 0; j < artists.length; j++) {						
						File artistsFile = new File(stylesDir + File.separator + artists[j]);
						if(artistsFile.isDirectory()) {							
							PreparedStatement pstm1 = con.prepareStatement(insertArtist);
							pstm1.setInt(1, ++iArtist);
							pstm1.setString(2, artists[j]);
							pstm1.setInt(3, i);
							pstm1.executeUpdate();
							pstm1.close();
							String[] albums = artistsFile.list();
							for(int k = 0; k < albums.length; k++) {
								File albumsFile = new File(artistsFile + File.separator + albums[k]);
								if(albumsFile.isDirectory()) {
									String[] songs = albumsFile.list();
									PreparedStatement pstm2 = con.prepareStatement(insertAlbum);
									pstm2.setInt(1, ++iAlbum);
									pstm2.setString(2, albums[k]);
									pstm2.setInt(3, iArtist);
									pstm2.executeUpdate();
									pstm2.close();
									for(int l = 0; l < songs.length; l++) {
										if((songs[l].contains(".jpg")) || 
												(songs[l].contains(".jpeg")) || 
												(songs[l].contains(".png"))) 
										{
											String s = albumsFile + File.separator + songs[l];
											PreparedStatement pstm3 = con.prepareStatement(updateAlbum);
											pstm3.setString(1, s);
											pstm3.setInt(1, iAlbum);
											pstm3.executeUpdate();
											pstm3.close();
										} else {
											int format = 0;
											if(songs[l].contains(Constants.AUDIO_FORMAT)) {
												format = 1;
											} else if(songs[l].contains(Constants.VIDEO_FORMAT)) {
												format = 2;
											}
											PreparedStatement pstm3 = con.prepareStatement(insertTitle);//FIXME execution e length no random
											pstm3.setInt(1, ++iTitle);
											pstm3.setString(2, songs[l]);
											pstm3.setInt(3, format);
											pstm3.setInt(4, (int)(1000 * Math.random()));
											pstm3.setInt(5, iAlbum);
											pstm3.setInt(6, (int)(1000 * Math.random()));
											pstm3.executeUpdate();
											pstm3.close();
										}
									}
								} else if((albumsFile.toString().contains(".jpg")) || 
										(albumsFile.toString().contains(".jpeg")) || 
										(albumsFile.toString().contains(".png")))
								{
									PreparedStatement pstm2 = con.prepareStatement(updateArtist);
									pstm2.setString(1, albumsFile.getAbsolutePath());
									pstm2.setInt(2, iArtist);
									pstm2.executeUpdate();
									pstm2.close();
								}
							}
						} else if((artistsFile.toString().contains(".jpg")) || 
								(artistsFile.toString().contains(".jpeg")) || 
								(artistsFile.toString().contains(".png")))
						{
							PreparedStatement pstm1 = con.prepareStatement(updateStyle);
							pstm1.setString(1, artistsFile.getAbsolutePath());
							pstm1.setInt(2, i);
							pstm1.executeUpdate();
							pstm1.close();
						}
					}
				} else {
					//segundo JOptionPane
					JOptionPane.showMessageDialog(null, stylesDir.getAbsoluteFile() + "\nEstá no diretório errado...");
				}
			}
		} catch(SQLException e) { 
			JOptionPane.showMessageDialog(null, "sql exception");
			e.printStackTrace();
		} finally {
			try {
				con.close();
			} catch(SQLException onConClose) {
				JOptionPane.showMessageDialog(null, "Houve erro no fechamento da conexão");
				onConClose.printStackTrace();
			}
		}
	}

	public void createDB() {
		deleteDBFiles();

		String createStyle = properties.getProperty("CREATE_STYLE");
		String createArtist = properties.getProperty("CREATE_ARTIST");
		String createAlbum = properties.getProperty("CREATE_ALBUM");
		String createTitle = properties.getProperty("CREATE_TITLE");
		
		try {
			Class.forName(driver);
			con = DriverManager.getConnection(url, user, password);
			stm = con.createStatement();
			stm.executeQuery(createStyle + createArtist + createAlbum + createTitle);
			
		} catch(ClassNotFoundException e){
			JOptionPane.showMessageDialog(null, "Classe nao encontrada");
			e.printStackTrace();
		} catch(SQLException e) { 
			JOptionPane.showMessageDialog(null, "Excessão SQL");
			e.printStackTrace();
		} finally {
			try {
				stm.execute("SHUTDOWN");
				con.close();
			} catch(SQLException onConClose) {
				JOptionPane.showMessageDialog(null, "Houve erro no fechamento da conexão");
				onConClose.printStackTrace();
			}
		}
	}
	
	public void deleteDBFiles() {
		try {
			File[] dbFiles = new File(dbHome).listFiles();
			for(int i = 0; i < dbFiles.length; i++) {
				dbFiles[i].delete();
			}
		} catch(SecurityException e) {
			e.printStackTrace();
		}
	}
	
	public static void main(String[] args) {
		DBLayer db = DBLayer.getInstance();
		db.createDB();
		db.insertDB();
		db.getTableData("SELECT * FROM ARTIST ORDER BY descr");
	}
}

String insertStyle = properties.getProperty("INSERT_STYLE");  
String insertArtist = properties.getProperty("INSERT_ARTIST");  

PreparedStatement insertStyleStatement  = con.prepareStatement(insertStyle);  
PreparedStatement insertArtistStatement  = con.prepareStatement(insertArtist );  

for( ... ) {
    insertStyleStatement.setString( 1, "test style" );
    insertStyleStatement.addBatch();
    for( ... ) {
        insertArtistStatement.setString( 1, "test artist" );
        insertArtistStatement.addBatch();
    }
}

// e depois de processar tudo
insertStyleStatement.executeBatch();
insertArtistStatement.executeBatch();

PreparedStatement pstmArtist = con.prepareStatement("SET WRITE_DELAY 0");
pstmArtist.executeUpdate();
pstmArtist.close();