org.sqlite.SQLiteException: [SQLITE_ERROR] SQL error or missing database (Connection is closed)

Пытаюсь подключиться к БД Sqlite с помощью JDBC.

public class HelloServlet extends HttpServlet {
public static Connection conn;
public static Statement stat;
public static ResultSet rs;
public static void Conn() throws ClassNotFoundException, SQLException, NamingException {
    Class.forName("org.sqlite.JDBC");
    conn = DriverManager.getConnection("jdbc:sqlite:C:\\Images.db");
    stat = conn.createStatement();
}
public static void addPicture(String arrayPicture) throws SQLException, ClassNotFoundException {
    try {
        Conn();
        String[] ss = arrayPicture.split(",");
        stat.execute("INSERT INTO 'ImagesItems'('ImageName','PointsArray') VALUES('" + ss[ss.length] + "','" + arrayPicture + "'");
    } catch (Exception e) {
        System.out.println(e);
    } finally {
        CloseDB();
    }
}
public static String getPicture(int id) throws SQLException, NamingException, ClassNotFoundException {
    Conn();
    rs = stat.executeQuery("SELECT 'PointsArray' FROM 'ImagesItems' WHERE '_id' = " + id);
    String rss = rs.toString();
    CloseDB();
    return rss;
}
public static void CloseDB() throws ClassNotFoundException, SQLException {
    conn.close();
    stat.close(); // Указывает на эту строку
    rs.close();
}
@Override
public void doGet(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws IOException {
    // httpServletResponse.getWriter().print("Hello from servlet");
}
@Override
public void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
    String ss = "";
    if ("POST".equalsIgnoreCase(req.getMethod())) {
        Scanner s = null;
        try {
            s = new Scanner(req.getInputStream(), "UTF-8");
            while(s.hasNext()) {
                ss += s.nextLine();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    if(ss.startsWith("1")) {
        try {
            addPicture(ss);
        } catch (SQLException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    } else if(ss.startsWith("2")) {
        try {
            String response = getPicture(1);
            res.setStatus(HttpServletResponse.SC_OK);
            res.getOutputStream().write(response.getBytes());
            res.getOutputStream().flush();
            res.getOutputStream().close();
        } catch (SQLException e) {
            e.printStackTrace();
        } catch (NamingException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
}

}

Выбрасывается исключение

org.sqlite.SQLiteException: [SQLITE_ERROR] SQL error or missing database (Connection is closed)
at org.sqlite.core.DB.newSQLException(DB.java:909)
at org.sqlite.core.CoreStatement.internalClose(CoreStatement.java:115)
at org.sqlite.jdbc3.JDBC3Statement.close(JDBC3Statement.java:35)
at org.sqlite.jdbc4.JDBC4Statement.close(JDBC4Statement.java:27)
at org.mycompany.myname.HelloServlet.CloseDB(HelloServlet.java:49)
at org.mycompany.myname.HelloServlet.getPicture(HelloServlet.java:43)
at org.mycompany.myname.HelloServlet.doPost(HelloServlet.java:84)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)

Указывает на эту строку в методе CloseDB

stat.close();

В чем может быть проблема?