VelocityServlet : Error processing the template

java.lang.RuntimeException: Closed Connection: OraclePooledConnection.getConnection() - SQLException Ocurred:Invalid or Stale Connection found in the Connection Cache
java.lang.RuntimeException: Closed Connection: OraclePooledConnection.getConnection() - SQLException Ocurred:Invalid or Stale Connection found in the Connection Cache at com.threeis.webta.jdbc.DbAccessor.getConnection(DbAccessor.java:49) at com.threeis.webta.HelpServlet.handleRequest(HelpServlet.java:123) at org.apache.velocity.servlet.VelocityServlet.doRequest(VelocityServlet.java:331) at org.apache.velocity.servlet.VelocityServlet.doGet(VelocityServlet.java:292) at javax.servlet.http.HttpServlet.service(HttpServlet.java:489) at javax.servlet.http.HttpServlet.service(HttpServlet.java:583) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:212) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:156) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:181) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:156) at org.tuckey.web.filters.urlrewrite.RuleChain.handleRewrite(RuleChain.java:176) at org.tuckey.web.filters.urlrewrite.RuleChain.doRules(RuleChain.java:145) at org.tuckey.web.filters.urlrewrite.UrlRewriter.processRequest(UrlRewriter.java:92) at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:389) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:181) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:156) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:168) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:90) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:483) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:130) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:93) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:679) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:346) at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:617) at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63) at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:934) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1690) at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52) at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:63) at java.lang.Thread.run(Thread.java:750) Caused by: java.sql.SQLRecoverableException: Closed Connection: OraclePooledConnection.getConnection() - SQLException Ocurred:Invalid or Stale Connection found in the Connection Cache at oracle.jdbc.pool.OraclePooledConnection.getConnection(OraclePooledConnection.java:327) at oracle.jdbc.pool.OracleImplicitConnectionCache.getConnection(OracleImplicitConnectionCache.java:412) at oracle.jdbc.pool.OracleDataSource.getConnection(OracleDataSource.java:513) at oracle.jdbc.pool.OracleDataSource.getConnection(OracleDataSource.java:202) at oracle.jdbc.pool.OracleDataSource.getConnection(OracleDataSource.java:184) at com.threeis.webta.jdbc.OracleConnectionManager.getConnection(OracleConnectionManager.java:216) at com.threeis.webta.jdbc.DbAccessor.getConnection(DbAccessor.java:35) ... 33 more