JDBC, servlets and strange "No operations allowed after connection closed" - mysql

Question

I have a servlet which put data to remote MySQL Database. From servlet I call post which run method, which connect to database, make operations on the table and close all resource. But, during prefom this, occur the "No operations allowed after connection closed. ". But if comment close methods on all resources, all works fine, and the database is update.
Below i present my code where I change the name of my object and error log:
public class MySqlManager {
Logger logger = Logger.getLogger("MySqlManager");
private Connection sqlConnection;
public Connection getConnenction() throws SQLException{
sqlConnection = DriverManager.getConnection(DataConstants.dbUrl, DataConstants.dbName, DataConstants.password);
return sqlConnection;
}
public MySqlManager() {
DriverManager.setLogWriter(new PrintWriter(System.out));
}
public void putData(String value1, String value2, String value3) throws SQLException{
Connection sqlConn = null;
Statement statement = null;
ResultSet resultSet = null;
PreparedStatement preparedStatement = null;
try {
//register for MySQL driver
Class.forName("com.mysql.jdbc.Driver").
//get connection for data base
sqlConn = getConnenction();
logger.info("Connect to database");
int id;
//create a statement which gets data from database
statement = sqlConn.createStatement();
//if exist row in column sec_id, get id of this row
String idQuery = "SELECT id FROM table1 WHERE sec_id = \'" + value3 + "\'";
logger.info("query=" + idQuery);
resultSet = statement.executeQuery(idQuery);
if(resultSet.next()){
//if row exist, update data in this row
id = resultSet.getInt("id");
preparedStatement = sqlConn.prepareStatement("UPDATE table1 SET col2 = ?, col2 = ?, col3 = ?, col4 = ? WHERE id = ?");
preparedStatement.setString(1, "some_tekst");
preparedStatement.setLong(2, 90854924897293);
preparedStatement.setString(3, "some_tekst");
preparedStatement.setString(4, "some_tekst"));
preparedStatement.setInt(5, id);
int i = preparedStatement.executeUpdate();
logger.info("Update " + i + " record");
}else{
//if row not exist, insert data to table1
preparedStatement = sqlConn.prepareStatement("INSERT INTO table1 (col2, col3, col4, col5, col6, col7, col8) VALUES (?, ?, ?, ?, ?, ?, ?)");
preparedStatement.setString(1, "some_tekst");
preparedStatement.setLong(2, 9146517234571);
preparedStatement.setString(3, "some_tekst");
preparedStatement.setString(4, "some_tekst");
preparedStatement.setInt(5, 0);
preparedStatement.setString(6, "some_tekst"));
preparedStatement.setString(7, "some_tekst"));
int i = preparedStatement.executeUpdate();
logger.info("Insert " + i + " record");
}
} catch (SQLException ex) {
Logger.getLogger(MySqlManager.class.getName()).log(Level.SEVERE, null, ex);
} catch (ClassNotFoundException ex) {
Logger.getLogger(MySqlManager.class.getName()).log(Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
Logger.getLogger(MySqlManager.class.getName()).log(Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
Logger.getLogger(MySqlManager.class.getName()).log(Level.SEVERE, null, ex);
}finally{
/*if I close all resources which has been defined above, I have an error:
SQLState(S1000) vendor code(0)
java.sql.SQLException: Operation not allowed after ResultSet closed
if I comment code below, all works fine, and database is update
*/
try { resultSet.close();} catch (Exception e) {}
try { statement.close();} catch (Exception e) {}
try { preparedStatement.close();} catch (Exception e) {}
try { closeConnection();} catch (Exception e) {}
}
}
public synchronized final void closeConnection() throws SQLException{
sqlConnection.close();
sqlConnection = null;
}
}
lis 21, 2014 12:56:32 PM com.test.database.MySqlManager putData
INFO: Connect to database
lis 21, 2014 12:56:32 PM com.test.database.MySqlManager putData
SEVERE: null
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.Util.getInstance(Util.java:386)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1014)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:988)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:974)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:919)
at com.mysql.jdbc.ConnectionImpl.throwConnectionClosedException(ConnectionImpl.java:1290)
at com.mysql.jdbc.ConnectionImpl.checkClosed(ConnectionImpl.java:1282)
at com.mysql.jdbc.ConnectionImpl.createStatement(ConnectionImpl.java:2653)
at com.mysql.jdbc.ConnectionImpl.createStatement(ConnectionImpl.java:2635)
at com.test.database.MySqlManager.putData(MySqlManager.java:33)
at com.test.database.SmackCcsClient.updateDB(SmackCcsClient.java:289)
at com.test.database.GCMNotification.doPost(GCMNotification.java:89)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
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:503)
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:950)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:314)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
SQLState(08003) vendor code(0)
EDIT:
Error log when it occur during getConnection()
DriverManager.getConnection("jdbc:mysql://mysql-testhost:3306/dbname")
trying sun.jdbc.odbc.JdbcOdbcDriver
*Driver.connect (jdbc:mysql://mysql-testhost:3306/dbname)
trying com.mysql.jdbc.Driver
SQLState(S1000) vendor code(0)
java.sql.SQLException: Operation not allowed after ResultSet closed
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1074)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:988)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:974)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:919)
at com.mysql.jdbc.ResultSetImpl.checkClosed(ResultSetImpl.java:804)
at com.mysql.jdbc.ResultSetImpl.realClose(ResultSetImpl.java:7331)
at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1527)
at com.mysql.jdbc.ConnectionImpl.loadServerVariables(ConnectionImpl.java:4156)
at com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3548)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2513)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2283)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:822)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:404)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:317)
at java.sql.DriverManager.getConnection(DriverManager.java:571)
at java.sql.DriverManager.getConnection(DriverManager.java:215)
at com.test.database.MySqlManager.getConnenction(MySqlManager.java:8)
at com.test.database.MySqlManager.putData(MySqlManager.java:52)
at com.test.database.SmackCcsClient.updateDB(SmackCcsClient.java:289)
at com.test.database.GCMNotification.doPost(GCMNotification.java:89)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
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:503)
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:950)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
SQLState(S1000) vendor code(0)
java.sql.SQLException: Operation not allowed after ResultSet closed
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1074)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:988)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:974)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:919)
at com.mysql.jdbc.ResultSetImpl.checkClosed(ResultSetImpl.java:804)
at com.mysql.jdbc.ResultSetImpl.realClose(ResultSetImpl.java:7331)
at com.mysql.jdbc.ResultSetImpl.close(ResultSetImpl.java:923)
at com.mysql.jdbc.StatementImpl.realClose(StatementImpl.java:2590)
at com.mysql.jdbc.StatementImpl.close(StatementImpl.java:582)
at com.mysql.jdbc.ConnectionImpl.loadServerVariables(ConnectionImpl.java:4188)
at com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3548)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2513)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2283)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:822)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:404)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:317)
at java.sql.DriverManager.getConnection(DriverManager.java:571)
at java.sql.DriverManager.getConnection(DriverManager.java:215)
at com.test.database.MySqlManager.getConnenction(MySqlManager.java:8)
at com.test.database.MySqlManager.putData(MySqlManager.java:52)
at com.test.database.SmackCcsClient.updateDB(SmackCcsClient.java:289)
at com.test.database.GCMNotification.doPost(GCMNotification.java:89)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
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:503)
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:950)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
SQLState(S1000) vendor code(0)
java.sql.SQLException: Operation not allowed after ResultSet closed
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1074)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:988)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:974)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:919)
at com.mysql.jdbc.ResultSetImpl.checkClosed(ResultSetImpl.java:804)
at com.mysql.jdbc.ResultSetImpl.realClose(ResultSetImpl.java:7331)
at com.mysql.jdbc.ResultSetImpl.close(ResultSetImpl.java:923)
at com.mysql.jdbc.StatementImpl.realClose(StatementImpl.java:2590)
at com.mysql.jdbc.StatementImpl.close(StatementImpl.java:582)
at com.mysql.jdbc.ConnectionImpl.buildCollationMapping(ConnectionImpl.java:1076)
at com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3556)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2513)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2283)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:822)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:404)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:317)
at java.sql.DriverManager.getConnection(DriverManager.java:571)
at java.sql.DriverManager.getConnection(DriverManager.java:215)
at com.test.database.MySqlManager.getConnenction(MySqlManager.java:8)
at com.test.database.MySqlManager.putData(MySqlManager.java:52)
at com.test.database.SmackCcsClient.updateDB(SmackCcsClient.java:289)
at com.test.database.GCMNotification.doPost(GCMNotification.java:89)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
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:503)
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:950)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
SQLState(S1000) vendor code(0)
java.sql.SQLException: Operation not allowed after ResultSet closed
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1074)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:988)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:974)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:919)
at com.mysql.jdbc.ResultSetImpl.checkClosed(ResultSetImpl.java:804)
at com.mysql.jdbc.ResultSetImpl.realClose(ResultSetImpl.java:7331)
at com.mysql.jdbc.ResultSetImpl.close(ResultSetImpl.java:923)
at com.mysql.jdbc.StatementImpl.realClose(StatementImpl.java:2590)
at com.mysql.jdbc.StatementImpl.close(StatementImpl.java:582)
at com.mysql.jdbc.ConnectionImpl.isAutoCommitNonDefaultOnServer(ConnectionImpl.java:3798)
at com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3644)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2513)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2283)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:822)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:404)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:317)
at java.sql.DriverManager.getConnection(DriverManager.java:571)
at java.sql.DriverManager.getConnection(DriverManager.java:215)
at com.test.database.MySqlManager.getConnenction(MySqlManager.java:8)
at com.test.database.MySqlManager.putData(MySqlManager.java:52)
at com.test.database.SmackCcsClient.updateDB(SmackCcsClient.java:289)
at com.test.database.GCMNotification.doPost(GCMNotification.java:89)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
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:503)
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:950)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
getConnection returning com.mysql.jdbc.Driver

Answer 1

Remove static modifier from sqlConnection object and getConnection() . it will work fine. The reason you get exception is this, by using static modifier you are creating a single connection object for all the objects of this class. If you close it once you are closing for all the servlets.
EDIT:
As discussed with david90 , the guy who asked this question, his problem was solved by changing the version of MySQL driver. from 5.1.24 to 5.1.34
Calling ResultSet.close() on an already closed ResultSet caused an SQLException.
Problem Exists in MySQL driver 5.1.24, while 5.1.34 fixed it.
Calling ResultSet.close() on an already closed ResultSet caused an SQLException. While the exception was silently discarded, it did result in performance issues. This fix makes Connector/J comply with the Java specification that when a ResultSet object is already closed, application of the close method on it should be a no-op. (Bug #16722637, Bug #67318)

Answer 2

Your code isn't thread-safe. sqlConnection should be a local variable everywhere, and never an instance or static member. Ditto the Statement and ResultSet variables.