the successor to sysdeo (and mongrel) for launching tomcat from eclipse

I’ve been using Mongrel to launch Tomcat in one click from Eclipse. In Neon, this stopped working. I learned in a comment on that blog post that there’s now a plugin called “Eclipse Tomcat Plugin 9.1.0” that does the same thing. It is advertised as being a successor to Sysdeo. And it is. But so was Mongrel. However, it works in Neon and does the same thing as Sysdeo/Mongrel so it is logically a successor to both!

The process was easy to get going:

  1. Uninstall Mongrel
  2. Restart Eclipse
  3. Install Eclipse Tomcat Plugin 9.1.0
  4. Restart Eclipse
  5. Preferences
  6. Tomcat  – choose version of Tomcat path and Tomcat home

That’s it!

mongrel tomcat launcher not working on neon

Edit: The solution is here

I used to use sydeo to launch Tomcat and then switched to Mongrel which I’ve been using for a few years. I had trouble with Mongrel in Eclipse Neon.


  • Clicking Start – get pop up with “The chosen operation is not available” and “Plugin net.sf.mongrel.plugin was unable to load class net.sf.mongrel.actions.StartActionDelegate” in the Eclipse log
  • Clicking Restart – get pop up with “The chosen operation is not available” and “Plugin net.sf.mongrel.plugin was unable to load class net.sf.mongrel.actions.RestartActionDelegate” in the Eclipse log
  • Clicking Stop – get pop up with “The chosen operation is not available” and “Plugin net.sf.mongrel.plugin was unable to load class net.sf.mongrel.actions.StopActionDelegate” in the Eclipse log
  • Opening Mongrel in the Eclipse preferences – get “An error has occurred while creating this preference page” and “Unable to create the selected preference page. An error occurred while automatically activating bundle net.sf.mongrel.plugin (1288).” The full Eclipse message in the error log is at the bottom of this post.

Attempt at solving

I checked the update site from Marketplace (by pasting the update site into “install new software” into Eclipse) and saw that there is only one version of Mongrel available. So it isn’t that I’m not using the latest version. I also tried uninstalling Mongrel and re-installing it. Nope. (You can uninstall a plugin through Marketplace if you installed it that way). Nothing.

I also learned I’m not the only one with this problem.


The workaround is to use the WTP (web tool plugin) that comes with Eclipse as described here. Not a big deal. I just like the single button approach. I had upgraded to Java 8 since I last used WTP so I immediately got “unable to start Tomcat” with this log message in the console:

java.lang.UnsupportedClassVersionError: com/javaranch/jforum/csrf/CsrfListener : Unsupported major.minor version 52.0 (unable to load class com.javaranch.jforum.csrf.CsrfListener)

It was immediately obvious to me that WTP was pointing to Java 7 since I successfully launched this project in Mars a few days ago. I clicked on “runtime” in the Tomcat profile and choose Java 8 from the pull down. This updated the classpath and then I was successful.

Full message in case curious



java.vendor=Oracle Corporation

BootLoader constants: OS=macosx, ARCH=x86_64, WS=cocoa, NL=en_US

Framework arguments:  -product org.eclipse.epp.package.jee.product -product org.eclipse.epp.package.jee.product -product org.eclipse.epp.package.jee.product -keyring /Users/nyjeanne/.eclipse_keyring

Command-line arguments:  -os macosx -ws cocoa -arch x86_64 -product org.eclipse.epp.package.jee.product -product org.eclipse.epp.package.jee.product -data file:/Users/nyjeanne/Documents/workspace/ -product org.eclipse.epp.package.jee.product -keyring /Users/nyjeanne/.eclipse_keyring



Fri Jun 24 10:48:29 EDT 2016

Unable to create the selected preference page.

java.lang.ClassNotFoundException: An error occurred while automatically activating bundle net.sf.mongrel.plugin (975).

at org.eclipse.osgi.internal.hooks.EclipseLazyStarter.postFindLocalClass(

at org.eclipse.osgi.internal.loader.classpath.ClasspathManager.findLocalClass(

at org.eclipse.osgi.internal.loader.ModuleClassLoader.findLocalClass(

at org.eclipse.osgi.internal.loader.BundleLoader.findLocalClass(

at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(

at org.eclipse.osgi.internal.loader.BundleLoader.findClass(

at org.eclipse.osgi.internal.loader.BundleLoader.findClass(

at org.eclipse.osgi.internal.loader.ModuleClassLoader.loadClass(

at java.lang.ClassLoader.loadClass(

at org.eclipse.osgi.internal.framework.EquinoxBundle.loadClass(

at org.eclipse.core.internal.registry.osgi.RegistryStrategyOSGI.createExecutableExtension(

at org.eclipse.core.internal.registry.ExtensionRegistry.createExecutableExtension(

at org.eclipse.core.internal.registry.ConfigurationElement.createExecutableExtension(

at org.eclipse.core.internal.registry.ConfigurationElementHandle.createExecutableExtension(

at org.eclipse.ui.internal.WorkbenchPlugin$

at org.eclipse.swt.custom.BusyIndicator.showWhile(

at org.eclipse.ui.internal.WorkbenchPlugin.createExtension(

at org.eclipse.ui.internal.PluginAction.createDelegate(

at org.eclipse.ui.internal.PluginAction.runWithEvent(

at org.eclipse.ui.internal.WWinPluginAction.runWithEvent(

at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(

at org.eclipse.jface.action.ActionContributionItem.lambda$5(

at org.eclipse.jface.action.ActionContributionItem$$Lambda$34/501727405.handleEvent(Unknown Source)

at org.eclipse.swt.widgets.EventTable.sendEvent(

at org.eclipse.swt.widgets.Display.sendEvent(

at org.eclipse.swt.widgets.Widget.sendEvent(

at org.eclipse.swt.widgets.Widget.sendEvent(

at org.eclipse.swt.widgets.Widget.sendEvent(

at org.eclipse.swt.widgets.Widget.notifyListeners(

at org.eclipse.swt.widgets.Display.runDeferredEvents(

at org.eclipse.swt.widgets.Display.readAndDispatch(

at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$

at org.eclipse.core.databinding.observable.Realm.runWithDefault(


at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(

at org.eclipse.ui.internal.Workbench$

at org.eclipse.core.databinding.observable.Realm.runWithDefault(

at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(

at org.eclipse.ui.PlatformUI.createAndRunWorkbench(

at org.eclipse.ui.internal.ide.application.IDEApplication.start(


at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(

at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(



at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(

at sun.reflect.DelegatingMethodAccessorImpl.invoke(

at java.lang.reflect.Method.invoke(

at org.eclipse.equinox.launcher.Main.invokeFramework(

at org.eclipse.equinox.launcher.Main.basicRun(


Caused by: org.osgi.framework.BundleException: Error loading bundle activator.

at org.eclipse.osgi.internal.framework.BundleContextImpl.start(

at org.eclipse.osgi.internal.framework.EquinoxBundle.startWorker0(

at org.eclipse.osgi.internal.framework.EquinoxBundle$EquinoxModule.startWorker(

at org.eclipse.osgi.container.Module.doStart(

at org.eclipse.osgi.container.Module.start(

at org.eclipse.osgi.framework.util.SecureAction.start(

at org.eclipse.osgi.internal.hooks.EclipseLazyStarter.postFindLocalClass(

… 51 more

Caused by: java.lang.ClassNotFoundException: org.eclipse.core.internal.compatibility.PluginActivator cannot be found by net.sf.mongrel.plugin_1.0.0.201101221622

at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(

at org.eclipse.osgi.internal.loader.BundleLoader.findClass(

at org.eclipse.osgi.internal.loader.BundleLoader.findClass(

at org.eclipse.osgi.internal.framework.BundleContextImpl.loadBundleActivator(

at org.eclipse.osgi.internal.framework.BundleContextImpl.start(

… 57 more

installing postgres and tomcat on the mac

Back when I was setting up my Mac, I installed Eclipse 3.7.  I also installed Postgres and Tomcat so I could run locally.  Postgres was either unnecessarily frustrating or it required knowledge I didn’t know I was missing.  The whole shared memory thing should have been a clue.  The good news is that I think I did almost everything wrong one could so I have a nice list of problems.  I wrote this up two months ago, but waited to post until I understood better what was going on.

I learned I didn’t know where the applications folder is on the hard drive.   First I learned you can view the path of a file in the finder. Which is all well and good.  It tells me the path is Macintosh HD > Applications > Eclipse.  Awesome.  On a UNIX file system, a directory has a slash up front.  Ok.  So I’m now at a UNIX prompt looking for it.  No Mac HD at the root level.  Volumes looks promising so I cd there and see Macintosh HD as a choice.  Great.  And there’s even an Applications folder under it with my apps!  I found it without having to use “find.”  That wasn’t bad, but it was more surprising than I expected.  I also noticed there is /Applications which will be more convenient next time.

Also, the “one click installer that doesn’t tell you what it is doing” installs some things by unzipping to the directory you are in, some files to /Library and presumably some files to who knows where.  Now I see the scripts I was expecting.

initdb doesn’t have enough privileges as me so I tried root and got initdb cannot be run as root.  Ok so it’s a real UNIX install where I need a user to run as.  I wasn’t expecting this because all my previous installs on the Mac have shielded me from a real UNIX install.

I thought I needed to create a  postgres user to run the database.  In Apple’s system preferences it tells me an id with that name already exists.  But /etc/passwd says nothing about it.  Running

dscl . -list /Users UniqueID

does turn up a postgres id. I need to figure out how the Mac Directory Service thing works.  Anyway, now that I know the postgres users exists I did “sudo passwd postgres” to reset the password to something I know.  Turns out the “sorry” message when trying to sudo to postgres wasn’t from an incorrect password.  Eureka!  I needed to type “sudo su postgres” and then type *my* admin password to switch.  Which kind of makes sense because my regular id isn’t allowed to switch user but my sudo admin user is.

I then changed owner of /Library/PostgreSQL recursively to postgres user.  A nice easy step.  (sudo chown -R postgres /Library/Post*)

Finally, I could run initdb and get prompted for the new superuser password!

I then tried to start the database and got a complaint the lock file already exists.

FATAL:  lock file “/tmp/.s.PGSQL.5432.lock” already exists

HINT:  Is another postmaster (PID 94) using socket file “/tmp/.s.PGSQL.5432”?bash-3.2$

Tried rebooting.  Error still there.  Turns out postgres automatically starts up.  I went on to create a user and database using the usual commands.

Then I opened pgadmin to see if I could access the database.

Connected – maintenance db is database name.

Almost there.  I used the wrong password for the id I created in postgres.  (This matters because the coderanch integration tests assume a certain password.  And because the one I picked I will never remember.)

alter user postgres with password ‘better_password’;

Importing data from file went smoothly.

Ongoing Little problems

  1. Copy paste from Eclipse doesn’t work.  You have to go through textedit.
  2. Postgres uses shift arrow key to select a line.  I wish Apple apps would all use the same convention.


  • – except for the building from source parts this was useful


Given how many problems I had with Postgres, I decided to follow a tutorial for Tomcat.  This one was easy to understand.  I know enough about the Mac to understand what the sudo is for (to be an admin.)  And the rest is pure UNIX – permissions, making a symbolic link, etc.