Mysql/j Connector Unloads Mysteriously Under Tomcat 6/JDK 6 - java

Thank you for taking time to look at my question.
I developing a Java WAR file intended for distribution to only one server at a time. So far, I have tested on 3 different servers with success, one Debian, one Ubuntu and the other, the Windows machine I'm developing on.
On the final deployment server, for some reason the app deploys fine, and upon each startup, runs well for about 3 minutes. Database connectivity works, everything runs fine. After 3 minutes however, I start seeing NoClassDefFoundError's consistently every time the app tries to access the DB.
I'm the following libraries with all of them packaged in the WAR file:
Mysql/j Connecter, latest version
ActiveObjects, 0.8.2
Jasorb 1.3
Jython 2.5.1 (for some scripting)
Tomcat 6.0.20
mod_python
Apache
The error:
Exception in thread "Timer-4"
java.lang.NoClassDefFoundError:
com/mysql/jdbc/SQLError
at com.mysql.jdbc.Util.handleNewInstance(Util.java:430)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:352)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:284)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:185)
at net.java.ao.DatabaseProvider.getConnectionImpl(DatabaseProvider.java:771)
at net.java.ao.DatabaseProvider.getConnection(DatabaseProvider.java:734)
at net.java.ao.EntityManager.find(EntityManager.java:666)
at net.java.ao.EntityManager.find(EntityManager.java:607)
at net.java.ao.EntityManager.find(EntityManager.java:579)
at com.sq.sa.SAPushAlertsTask.run(SAPushAlertsTask.java:32)
at java.util.TimerThread.mainLoop(Timer.java:512)
at java.util.TimerThread.run(Timer.java:462)
Caused by:
java.lang.ClassNotFoundException:
com.mysql.jdbc.SQLError
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:138
7)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:123
3)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
... 13 more

Either your MySQL/J connector is somehow broken OR (more likely) you have another somewhere jar in your classpath that has only some of the classes from MySQL's JDBC driver. Either way, "com/mysql/jdbc/SQLError" class can't be found.
Your application runs fine the first few minutes, then when some error occurs the above class can't be loaded which throws the exception as posted. Check your entire classpath (CLASSPATH env. variable + tomcat's lib + webapp's lib) and see whether a) you actually do have SQLError in it and b) MySQL JDBC driver does not occur more than once.
Once the above is fixed, you'll get an actual error that's causing this and should be able to take it from there.

Related

How to debug java.lang.ClassNotFoundException during Tomcat startup?

When Tomcat loads my war, I get this error:
Exception in thread "ClientMessageReceptor0" java.lang.NoClassDefFoundError: java/net/Inet6Address
at org.jacorb.orb.iiop.IIOPAddress.getNetworkInetAddresses(IIOPAddress.java:675)
at org.jacorb.orb.iiop.IIOPAddress.getLocalHost(IIOPAddress.java:591)
at org.jacorb.orb.iiop.IIOPAddress.getLocalHostAddress(IIOPAddress.java:574)
at org.jacorb.orb.listener.SSLListenerUtil.processException(SSLListenerUtil.java:73)
at org.jacorb.orb.iiop.IIOPConnection.handleCommFailure(IIOPConnection.java:77)
at org.jacorb.orb.etf.StreamConnectionBase.read(StreamConnectionBase.java:139)
at org.jacorb.orb.giop.GIOPConnection.getMessage(GIOPConnection.java:389)
at org.jacorb.orb.giop.GIOPConnection.receiveMessagesLoop(GIOPConnection.java:541)
at org.jacorb.orb.giop.GIOPConnection.receiveMessages(GIOPConnection.java:533)
at org.jacorb.orb.giop.MessageReceptor.doWork(MessageReceptor.java:69)
at org.jacorb.util.threadpool.ConsumerTie.run(ConsumerTie.java:60)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ClassNotFoundException: Illegal access: this web application instance has been stopped already. Could not load [java.net.Inet6Address]. 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.checkStateForClassLoading(WebappClassLoaderBase.java:1375)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1226)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1188)
Our application uses Tomcat v9.0.41 and JDK 1.8.0_111 . This same combination works for others in my team and also it worked for me sometime back. I'm not sure what changed now. I have looked at other similar posts and they suggest mismatch between Tomcat and JDK version. But above combination of Tomcat and JDK works for others.
I have removed all other JDK and JRE version on my system.
Ensured JAVA_HOME points to JDK 1.8.0_111 and PATH points to correct JRE.
Any pointers on how to debug this further? Can I turn on some logging during Tomcat startup to see what paths are being used by Tomcat? Any suggestions are highly appreciated :).

Eclipse and Tomcat 8.0.35 app ERROR: Illegal access: this web application instance has been stopped already

I'm running a Java app in Eclipse EE Oxygen 32 bit in a 64 machine since the program will be transferred to a 32 bit machine later. The app is connected to mysql installed through Wampserver, and the server I'm using in the app is Apache Tomcat 8.0.35. When I run the app in "Run as> Run on Server" inside Eclispe. I get the following error message in "Console":
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:1372)
at org.apache.catalina.loader.WebappClassLoaderBase.getResource(WebappClassLoaderBase.java:1042)
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)
How can I debug that?
The java code is totally portable across 32-bit and 64-bit platforms, doesn't make sense to use a 32 bit Eclipse version.
To solve your issue, just restart the Tomcat server to get rid of the older cache then try again.
If still doesn't work:
Restart Eclipse
Clean up Eclipse working directory (see #nitind comment).
Run Eclipse in clean mode (see this)

Tomcat not running for a JAR file

I am using Postman alongside a JAR file that runs a REST service that holds some contacts. However when I try to run the JAR file by using: java -jar ContactListRESTService.jar in Powershell, I am seeing a bunch of errors that Apache Tomcat could not run. Postman also doesn't recognize the localhost.
Caused by: java.lang.IllegalStateException: Tomcat connector in failed state
at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.start(TomcatEmbeddedServletContainer.java:159)
Caused by: java.lang.IllegalStateException: Tomcat connector in failed state
at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.start(TomcatEmbeddedServletCntainer.java:159) ~[spring-boot 1.3.7.RELEASE.jar!/:1.3.7.RELEASE]
I have tried uninstalling and reinstalling JAVA SE per some guidance from a mentor with no results.
If anyone can point me in the right direction please.

VisualVM is unable to profile a web application on Eclipse

I would like to profile my Spring Web Application that is running on Tomcat and Eclipse. I added VisualVM to the Eclipse and followed below steps to run the application for profiling.
Right click on the application name >
Run As >
Run Configuration >
Java Application >
'Selected Project' >
Set 'org.apache.catalina.starup.Boostrap' as a value for Main class,
also selected VisualVM as the Launcher > clicked on Run button.
The VisualVM starts but shows following message:
"Cannot open requested application"
Under local I can see VisualVM, Eclipse and Tomcat.
Following exception will be thrown and shown on console as well:
Exception in thread "main" java.lang.NoClassDefFoundError:
org/apache/juli/logging/LogFactory
at org.apache.catalina.startup.Bootstrap.<clinit>(Bootstrap.java:59)
Caused by: java.lang.ClassNotFoundException: org.apache.juli.logging.LogFactory
at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 1 more
I reckon the issue is because of wrong server selected. Maybe I should choose Tomcat but not sure how.
Probably an issue with an incomplete classpath when the VisualVM plugin launches Tomcat. You could try to correct the classpath of the start configuration which you created (e.g. try to add bin/tomcat-juli.jar from your tomcat installation) but I doubt this will work easily.
You can try the following:
start your Tomcat, e.g. from Eclipse
then manually start VisualVM: It is actually part of the JDK and located in <JDK dir>/bin/jvisualvm(.exe)
in the application list you should see the Tomcat process and then you can open it with a double click.
Try using Java Mission Control by running jmc. It is included in recent versions of the JDK.
See the getting started doc at http://docs.oracle.com/javacomponents/jmc-5-5/jmc-user-guide/index.html
Run your application, then open the jmc window and connect to the Tomcat process.
This is caused when a class file that your code depends on is not found at run time. This is purely an issue with the class path. Either the class is not exists in the class path or you have a different version of JAR file in the class path. The exception will go away if the class path is corrected.

Matlab has critical error from clean install (possibly OS X related?)

Using R2014b on OS X Yosemite.
Exception in thread "Startup Class Loader" java.lang.UnsatisfiedLinkError: jogamp.common.jvm.JVMUtil.initialize(Ljava/nio/ByteBuffer;)Z
at jogamp.common.jvm.JVMUtil.initialize(Native Method)
at jogamp.common.jvm.JVMUtil.<clinit>(JVMUtil.java:58)
at com.jogamp.common.os.Platform$1.run(Platform.java:212)
at java.security.AccessController.doPrivileged(Native Method)
at com.jogamp.common.os.Platform.<clinit>(Platform.java:179)
at javax.media.opengl.GLProfile.<clinit>(GLProfile.java:83)
at com.mathworks.hg.peer.JavaSceneServerPeer.initializeJOGL(JavaSceneServerPeer.java:114)
at com.mathworks.hg.peer.JavaSceneServerPeer.<clinit>(JavaSceneServerPeer.java:100)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:190)
at com.mathworks.mde.desk.StartupClassLoader.loadClass(StartupClassLoader.java:258)
at com.mathworks.mde.desk.StartupClassLoader.access$900(StartupClassLoader.java:25)
at com.mathworks.mde.desk.StartupClassLoader$2.run(StartupClassLoader.java:244)
at java.lang.Thread.run(Thread.java:745)
This pops up the moment I start matlab. I am unable to use imagesc() or imshow() and probably loads of other functions, because matlab crashes with Caught unexpected exception of unknown type. instantly.
I'm at my wits end. The matlab install is fresh, and so is the OS. Same problem using the Java from Apple or the Java from Oracle.
EDIT: Response from MathWorks is that integration with Maple breaks everything. Emptying the .maplerc.sh file in the /bin/ directory fixes everything.
This issue is caused by having installed Matlab integration through maple. A file called .maplerc.sh is placed within the /bin/ folder in the matlab .app, and it apparently breaks everything. You cannot delete the file (this causes matlab to not launch on start up) but you can erase its contents. This will create an error upon launch, but you can ignore it and everything will work fine.
Uninstall matlab and maple, and reinstall maple and matlab without integration will fix the issue entirely.
Replace the contents of the file /Applications/MATLAB_R2014b.app/bin/.maplerc.sh by an empty line (as suggested by the other answer from Dorako), and
Modify the file /Applications/MATLAB_R2014b.app/toolbox/local/matlabrc.m, by searching for Maple in this text file and comment-out or remove the part between the two lines containing %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%.
The second step ensures that there is no error or warning message any more on startup, so that re-installing the programs is not necessary.

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