Technology Tales

Adventures & experiences in contemporary technology

Getting Eclipse to start without incompatibility errors on Linux Mint 19.1

12th June 2019

Recent curiosity about Java programming and Groovy scripting got me trying to start up the Eclipse IDE that I had install on my main machine. What I got instead of a successful application startup was a message that included the following:

!MESSAGE Exception launching the Eclipse Platform:
!STACK
java.lang.ClassNotFoundException: org.eclipse.core.runtime.adaptor.EclipseStarter
at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:466)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:566)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:499)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:626)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:584)
at org.eclipse.equinox.launcher.Main.run(Main.java:1438)
at org.eclipse.equinox.launcher.Main.main(Main.java:1414)

The cause was a mismatch between Eclipse and the installed version of Java that it needed in order to run. After all, the software itself is written in the Java language and the installed version from the usual software repositories was too old for Java 11. The solution turned out to be installing a newer version as a Snap (Ubuntu’s answer to Flatpak). The following command did the needful since Snapd already was running on my machine:

sudo snap install eclipse --classic

The only part of the command that warrants extra comment is the --classic switch since that is needed for a tool like Eclipse that needs to access a host file system. On executing, the software was downloaded from Snapcraft and then installed within its own bundle of dependencies. The latter adds a certain detachment from the underlying Linux installation and ensures that no messages appear because of incompatibilities like the one near the start of this post.

You always can install things yourself…

26th November 2009

With Linux distributions offering you everything on a plate, there is a temptation to stick with what they offer rather than taking things into your own hands. For example, Debian’s infrequent stable releases and the fact that they don’t seem to change software versions throughout the lifetime of such a release means that things such as browser versions are fixed for the purposes of stability; Lenny has stuck with Firefox 3.06 and called it Iceweasel for some unknown reason. However, I soon got to grabbing a tarball for 3.5 and popped its contents into /opt where the self-contained package worked without a hitch. The same modus operandii was used to get in Eclipse PDT and that applied to Ubuntu too until buttons stopped working, forcing a jumping of ship to Netbeans. Of course, you could make a mess when veering away from what is in a distribution but that should be good enough reason not to get carried away with software additions. With the availability of DEB packages for things like Adobe Reader, RealPlayer, VirtualBox, Google Chrome and Opera, keeping things clean isn’t so hard. Your mileage may vary when it comes to how well things work out for you but I have only ever had the occasional problem anyway.

What reminded me of this was a recent irritation with the OpenOffice package included in Ubuntu 9.10 whereby spell checking wasn’t working. While there were thoughts about is situ fixes like additional dictionary installations, I ended up plumping for what could be called the lazy option: grabbing a tarball full of DEB packages from the OpenOffice website and extracting its contents into /tmp and, once the URE package was in place, installing from there using the command:

dpkg -i o*

To get application shortcuts added to the main menu, it was a matter of diving into the appropriate subfolder and installing from the GNOME desktop extension package. Of course, Ubuntu’s OpenOffice variant was removed as part of all this but, if you wanted to live a little more dangerously, the external installation goes into /opt so there shouldn’t be too much of a conflict anyway. In any case, the DIY route got me the spell checking in OpenOffice Writer that I needed so all was well and another Ubuntu rough edge eradicated from my life, for now anyway.

When buttons stop working…

16th November 2009

One of the things that stopped working as it should after my recent Ubuntu 9.10 upgrade was the Eclipse PDT installation that I had in place. Editing files went a bit haywire and creating projects had me pushing buttons with nothing happening. Whether this was a Java or GNOME issue, I don’t know but I found it happening too on openSUSE 11.2 (there should be more on that distro in a later entry). That was enough to get me looking again at Netbeans.

In both openSUSE (NB version 6.5) and Ubuntu (NB version 6.7.1), I plucked the default offering of Netbeans from the respective software repositories and added the PHP plugin in both cases. Unlike when I last gave the platform a go, things seemed to go smoothly and it looks to have replaced Eclipse for PHP development duties. Project scanning make take a little while but it’s far from annoying and my earlier dalliance with using Netbeans as a PHP editor was stymied by performance that was so sluggish as to make the thing a pain to use. Up to now, Netbeans’ footprints when it comes to its use of PC power never was light so I am wondering if dual-core and quad-core CPU’s help along with a copious supply of RAM. Only time will tell if these inital positive impressions stay the course and I’ll be keeping an open mind for now.

A collection of lessons learned from using Eclipse on Ubuntu

9th July 2008

I have been running into a few woes on the home computing front that may or may not give rise to a number of posts on here. Having my Windows VM’s going awry on VMware is a more worrying development with my need to use a Windows-based application for my hillwalking mapping  but I am going to devote this entry to a spot of bother that I started to have with Eclipse, if only because I managed to sort that one out.

Up to yesterday, I had all my offline website development stuff in a single project area for sake of ease of testing. I suppose that I got led into this by my use of Dreamweaver and the way that it sets up what it calls Sites. Applying that same of working to Quanta Plus and Netbeans just chokes up the respective IDE’s and makes them less usable. Until recently, Eclipse escaped this because it seemed to check if a file had changed when you tried editing it and asked you if you wanted the latest version. This stopped in the last few days for whatever reason and it started to stall just like the others.

Naturally, I wanted to set it back as before so a certain amount of investigation was in order. I ended up refreshing my installation in /usr/lib, a manual extraction of the Eclipse PDT archive but that didn’t resolve the issue. In fact, it created another one but we’ll talk about that later. Creating a smaller project made it all work again and I’ll be building up a number of these.

The new issue pertained to the creation and selection of the Eclipse workspace. There was no problem using what I wanted it to use but it wouldn’t remember the setting. There was more blundering about before I happened on the cause: access permissions. I copied the new Eclipse files in as the root user and that meant that Eclipse couldn’t update its setting when I was running it under my own account. Running the editor using sudo sorted out the workspace selection issue for now but a more permanent fixing such as giving myself write access to the configuration directory and what’s in there remains an outstanding task.

The mention of the Eclipse workspace brings me back to the way that it was working before the upheaval hit me. It does keep a copy of every file that you edit in there and maybe more besides. Thus, having a copy of every file in the project would have meant that it didn’t need to do the constant churning being performed by Quanta or Netbeans. That’s impression that I have but I’ll sticking with smaller project bundles from now on. Learning all this was useful.

A reasonable requirement of an IDE

20th May 2008

I have been having a play with NetBeans IDE Early Access for PHP and, while it has a lot to offer, one impression remains uppermost in my mind: it is so slow. I might have a project with a lot of files in it but start-up takes an age because of project checking. Other functionality such as text searching is far from speedy either. The sluggishness probably arises from this release being very early in its life cycle and it reminds me of how slow older versions of the Java IDE were, even if this is slower. For PHP development, I’ll be giving NetBeans a while to mature before taking another look at it.

On a similar note, I recently dispatched Quanta Plus from my system for sluggish start-ups and will not return to it because other alternatives such as Bluefish and Eclipse PDT fit my needs much better. I like my editors to be slick and responsive and Quanta has been around long enough for any slowness to be knocked out of it. However, I get the feeling that the extras have added bloat while I expect any additional functionality that I never use not to get in my way. It is for the latter reason that I was always able to get on with Dreamweaver and even run it on Ubuntu using the WINE library. If I really wanted a stripped out yet functional editor, Gedit would do most of what I need -- it colour codes syntax for a variety of languages for a start -- but it’s always handy to have a file system explorer window incorporated and I value any syntax checking and auto-completion as well. So, it looks as if Eclipse and Bluefish could be serving my needs for a while to come alongside so use Dreamweaver for online editing of website files.

A NetBeans 6.1 Review

11th May 2008

I have been thinking of sharing my thoughts on using IDE‘s such as NetBeans, Eclipse and Komodo Edit from a web developer’s point of view for a while but it has still to come. In the meantime, Java Boutique have shared their thoughts on NetBeans 6.1 and I think that they are well worth a look. In fact, I downloaded a copy for my own use off the back of this. MySQL capabilities look especially intriguing.

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