mysql服务器继续给出以下异常
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
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.throwConnectionClosedException(ConnectionImpl.java:1187)
at com.mysql.jdbc.ConnectionImpl.checkClosed(ConnectionImpl.java:1182)
at com.mysql.jdbc.ConnectionImpl.prepareStatement(ConnectionImpl.java:4071)
at com.mysql.jdbc.ConnectionImpl.prepareStatement(ConnectionImpl.java:4040)
at com.iseva.Servlet.DS_status_search.doGet(DS_status_search.java:47)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:94)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:504)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:620)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:502)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1104)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:684)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1519)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1475)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
Nov 30, 2017 2:32:30 PM org.apache.catalina.core.StandardContext reload
INFO: Reloading Context with name [/i_seva] has started
Nov 30, 2017 2:32:30 PM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesJdbc
WARNING: The web application [i_seva] registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
Nov 30, 2017 2:32:30 PM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
WARNING: The web application [i_seva] appears to have started a thread named [Abandoned connection cleanup thread] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
java.lang.Object.wait(Native Method)
java.lang.ref.ReferenceQueue.remove(Unknown Source)
com.mysql.jdbc.AbandonedConnectionCleanupThread.run(AbandonedConnectionCleanupThread.java:64)
java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
java.lang.Thread.run(Unknown Source)
Nov 30, 2017 2:32:31 PM org.apache.catalina.loader.WebappClassLoaderBase checkStateForResourceLoading
INFO: Illegal access: this web application instance has been stopped already. Could not load []. The following stack trace is thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access.
java.lang.IllegalStateException: Illegal access: this web application instance has been stopped already. Could not load []. The following stack trace is thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access.
at org.apache.catalina.loader.WebappClassLoaderBase.checkStateForResourceLoading(WebappClassLoaderBase.java:1353)
at org.apache.catalina.loader.WebappClassLoaderBase.getResource(WebappClassLoaderBase.java:1029)
at com.mysql.jdbc.AbandonedConnectionCleanupThread.checkContextClassLoaders(AbandonedConnectionCleanupThread.java:90)
at com.mysql.jdbc.AbandonedConnectionCleanupThread.run(AbandonedConnectionCleanupThread.java:63)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Nov 30, 2017 2:32:32 PM org.apache.jasper.servlet.TldScanner scanJars
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
Nov 30, 2017 2:32:32 PM org.apache.catalina.core.StandardContext reload
INFO: Reloading Context with name [/i_seva] is completed
当尝试定期访问数据库时，我不理解这个问题，所以我搜索了它并且发现它可以使用ping来解决
如何使用jdbc进行ping
我的连接类看起来像这样
package Connectionfactory;
import java.sql.Connection;
import java.sql.DriverManager;
public class ConnectionFactory {
static Connection cn;
static
{
try{
Class.forName("com.mysql.jdbc.Driver");
}
catch(Exception e)
{
e.printStackTrace();
}
}
public static Connection getConnection()
{
try
{
cn=DriverManager.getConnection("jdbc:mysql://mydb.cn89qwuvudeu.us-east-2.rds.amazonaws.com:3306","XXX","XXXXXXXX");
}
catch(Exception p)
{
p.printStackTrace();
}
return cn;
}
}
请帮助我，这需要添加上面ConnectionFactory中的任何方法，还是有其他方法可以解决它。
答案 0 :(得分：0)
建立连接可能对您有所帮助
package Connectionfactory;
import java.sql.Connection;
import java.sql.DriverManager;
public class ConnectionFactory {
private Connection cn;
public ConnectionFactory () {
super();
}
public Connection getConnection()throws ClassNotFoundException, SQLException{
Class.forName("com.mysql.jdbc.Driver");
cn=DriverManager.getConnection("jdbc:mysql://mydb.cn89qwuvudeu.us-east-2.rds.amazonaws.com:3306","root","pwd");
return cn;
}
}