500 Servlet Exception

[show] java.lang.IllegalStateException: connection is closed

java.lang.IllegalStateException: connection is closed
	at com.caucho.sql.UserConnection.getMConn(UserConnection.java:1366)
	at com.caucho.sql.UserConnection.getDriverConnection(UserConnection.java:1348)
	at com.caucho.sql.UserConnection.prepareCall(UserConnection.java:487)
	at pl.com.pointer.eshop.DB.getKrajZIP(DB.java:3411)
	at BaseServlet.doResponse(BaseServlet.java:727)
	at BaseServlet.doResponseMessage(BaseServlet.java:547)
	at BaseServlet.doGetPost(BaseServlet.java:316)
	at BaseServlet.doGet(BaseServlet.java:146)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:120)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:97)
	at com.caucho.server.dispatch.ServletFilterChain.doFilter(ServletFilterChain.java:109)
	at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:156)
	at com.caucho.server.webapp.AccessLogFilterChain.doFilter(AccessLogFilterChain.java:95)
	at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:289)
	at com.caucho.server.hmux.HmuxRequest.handleInvocation(HmuxRequest.java:473)
	at com.caucho.server.hmux.HmuxRequest.handleRequestImpl(HmuxRequest.java:374)
	at com.caucho.server.hmux.HmuxRequest.handleRequest(HmuxRequest.java:341)
	at com.caucho.network.listen.TcpSocketLink.dispatchRequest(TcpSocketLink.java:1345)
	at com.caucho.network.listen.TcpSocketLink.handleRequest(TcpSocketLink.java:1301)
	at com.caucho.network.listen.TcpSocketLink.handleRequestsImpl(TcpSocketLink.java:1285)
	at com.caucho.network.listen.TcpSocketLink.handleRequests(TcpSocketLink.java:1193)
	at com.caucho.network.listen.TcpSocketLink.handleAcceptTaskImpl(TcpSocketLink.java:992)
	at com.caucho.network.listen.ConnectionTask.runThread(ConnectionTask.java:117)
	at com.caucho.network.listen.ConnectionTask.run(ConnectionTask.java:93)
	at com.caucho.network.listen.SocketLinkThreadLauncher.handleTasks(SocketLinkThreadLauncher.java:169)
	at com.caucho.network.listen.TcpSocketAcceptThread.run(TcpSocketAcceptThread.java:61)
	at com.caucho.env.thread2.ResinThread2.runTasks(ResinThread2.java:173)
	at com.caucho.env.thread2.ResinThread2.run(ResinThread2.java:118)