TOPIC: JAVA DEVELOPMENT TOOLS
Getting Eclipse to start without incompatibility errors on Linux Mint 19.1
12th June 2019Recent curiosity about Java programming and Groovy scripting got me trying to start up the Eclipse IDE that I had installed 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 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.
If all else fails...
3rd June 2010
Two problems have come my way that were resolved by removing configuration files and going again. Both affected Linux installations that I have. The Ubuntu installation on my main PC is working well, but I ran into trouble starting up NetBeans 6.8. No GUI would ever appear but taking away the .netbeans folder from my home area allowed a fresh start with the IDE starting up as it should. To date, not all the various projects that I have are restored, but that can be done as I go along. Plugins for PHP development needing reinstatement, but that was another easy thing to achieve; just go to Tools > Plugins on the menus and work with the dialogue box that appears to download and install the needful.
The inspiration for taking the configuration folder from the home area came from needing to address a misadventure with a Debian VM. Perhaps foolishly, I went using gconf-editor on there and messed up the appearance of the terminal window with whatever change I made. Getting rid of the .gconf folder restored order with its recreation by the system. Next time, remembering what changes have been made and reversing them might be the best course of action...
A collection of lessons learned from using Eclipse on Ubuntu
9th July 2008I 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. While 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, 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 the 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, only for that not to resolve the issue. In fact, it created another one that we'll talk about 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. While there was no problem using what I wanted it to use, it wouldn't remember the setting. There was more blundering about before I happened on the cause: access permissions. Then, 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 its contents 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 the impression that I have, so I'll stick with smaller project bundles from now on. Learning all this was useful.
A reasonable requirement of an IDE
20th May 2008I 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. While I might have a project with many files in it, 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.