i have problem. When I try to connect to a remote database on the server. I get this exception.
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up. at sun.reflect.GeneratedConstructorAccessor27.newInstance(Unknown Source) I have shortened full stack trace.
I seem to close all the connections. Everything works on the local database, what's the problem? Here is an example of connecting
public static Connection getConnection() throws ClassNotFoundException, SQLException { Class.forName("com.mysql.jdbc.Driver"); return DriverManager.getConnection( "jdbc:mysql://zrn.mysql.ukraine.com.ua:3306/zrn_program?" + "autoReconnect=true&useSSL=false", "USERNAME", "PASSWORD"); } Sample queries
public static List<Training> showTraining(String date){ List<Training> trainings = new ArrayList<>(); try (Connection con = Connector.getConnection(); PreparedStatement pst = con.prepareStatement("SELECT * FROM view_training" + " WHERE training_date = ?")){ pst.setDate(1, Date.valueOf(date)); ResultSet rs = pst.executeQuery(); while (rs.next()){ trainings.add(new Training(rs.getInt("training_id"),rs.getString("patient"), rs.getString("specialist"),rs.getString("training_date"), rs.getString("training_time"),rs.getBoolean("hasTicket"), rs.getString("category"),rs.getString("status"),rs.getDouble("sum"), rs.getString("color"))); } rs.close(); } catch (SQLException | ClassNotFoundException e) { e.printStackTrace(); } return trainings; } Help, please.
UPD1
this full stack trace
om.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up. at sun.reflect.GeneratedConstructorAccessor27.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:422) at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) at com.mysql.jdbc.Util.getInstance(Util.java:408) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:918) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:897) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:886) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:860) at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2163) at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2088) at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:806) at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47) at sun.reflect.GeneratedConstructorAccessor25.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:422) at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:410) at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:328) at java.sql.DriverManager.getConnection(DriverManager.java:664) at java.sql.DriverManager.getConnection(DriverManager.java:247) at database.Connector.getConnection(Connector.java:13) at database.DBTraining.showConsultation(DBTraining.java:268) at servlet.views.Main.doGet(Main.java:58) at javax.servlet.http.HttpServlet.service(HttpServlet.java:624) at javax.servlet.http.HttpServlet.service(HttpServlet.java:731) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:614) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2522) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2511) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745) Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server. at sun.reflect.GeneratedConstructorAccessor26.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:422) at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:989) at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:341) at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2251) at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2104) ... 37 more Caused by: java.net.ConnectException: Connection timed out: connect at java.net.DualStackPlainSocketImpl.connect0(Native Method) at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:79) at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:345) at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206) at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188) at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172) at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) at java.net.Socket.connect(Socket.java:589) at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:211) at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:300) ... 39 more