Eclipse version control - problems with project no longer showing in workspace - java

I'm trying to figure out which files to check in to version control when using Eclipse for Android development. I have a workspace with a single project. I found this which suggested that the .metadata folder did not need to be controlled (minus the comment there about launch params, however I don't mind re-picking those again on a different machine).
If I remove the .metadata folder then open Eclipse the project is no longer shown. I searched for posts on this symptom and they suggest re-importing the project. This solution doesn't make sense here, I'm trying to check in whatever is needed so another developer can open the workspace and see the project and work on it. Having them move the project then re-import it would be a bit messy.
So which files should I be version controlling so that someone else can get the latest and be able to open the project without controlling a bunch of user specific preferences?

I have had similar experience using Eclipse for version control, and decided to quit using it because it is very annoying and buggy. Now, for git, I use SourceTree, which I prefer over eclipse version control. I think you should version control the source code folders, along with configurations, and other files you program needs to function, but never the executable files. If the other person is using Eclipse, for easiness, it is good idea to include the .classpath configuration file. If not, then the other person would need to clone the repository and make the required changes so that it works with his/her IDE.

I think I've settled on the following approach. This seems to work well so far and avoids some of the headaches mentioned in my original question.
1) each developer creates an Eclipse workspace on their machine somewhere, outside of version control; only the project directory is checked into version control - the workspace is completely uncontrolled
2) developers checkout the project directory from version control (in a different directory structure than where the workspace was created) and then use File >> Import, but they leave the "copy into workspace" unchecked.
So with the above, you can checkout from version control and work with the files right where they were checked out. There's no need to move them out then import them back in. When you import with the copy option unchecked, the workspace (which itself is not controlled) is just referencing the files where they're at on disk.
The only minor downside is that any workspace stuff has to be setup individually. Other articles mention controlling the launch params, but so far this hasn't been an issue - pretty easy to pick that once the first time you launch.
So anyway, hopefully this helps someone else :) This seems to be a reasonably smooth way to do it and avoids the issues we ran into initially.

Related

Eclipse workspace vs. regular directory

Note: I don't find this being a duplicate of any question. I have done a lot of research on this (few hours, read whole Google about workspaces probably - it's a metaphor of course) but couldn't find the answer to my problem.
So I have done some programming in Java and mainly used Eclipse for it (when projects were getting more complex, before I had used Vi). I was always working in that default workspace $HOME/eclipse-workspace because I never really understood the point of workspaces.
I am back to programming in Java, installed Eclipse and get prompted to Select a directory as workspace which kindly offered me to use /home/campovski/eclipse-workspace. Before I would just hit Launch but now I started getting curious. What are these workspaces, what are they used for...?
I have done some research:
Eclipse Workspaces: What for and why? (SE)
Eclipse - Workspaces (Tutorials point)
Documentation
I also followed the links that were provided in answers to the first link but none gave me the answer to my question:
What is the difference between a directory and a workspace?
As is stated in third link: A workspace can have any number of projects, each of which can be stored in a different location in some file system. Ok, this might be useful, but what is the problem of including all projects in one parent directory which could serve instead of a workspace?
If we take Matlab for example:
There you have a directory selection menu on the left, just like in Eclipse. The current directory you are in is selected as a working directory and any Matlab function and scripts declared in this directory can be executed in the Command Window. The analogy from Eclipse would be as to import a function from different folder.
So my question to rephrase it is, is there anything else to workspaces than workspace just being a collection of projects, folders and files, just like a normal directory, except that in workspace there can be projects from different paths.
Workspace it's like user's homedir in linux.
Workspaces bind together JRE version, installed servers, and if you're using server connectors, all the data and temporary WARs, EARs are saved there (.metadata/plugins). Switching workspace is for switching context of your work: project, client, language, paradigm ... Workspace is the directory from where ECLIPSE bootstraps itself up. All local dependency resolutions ends up in workspace directory.
VisualStudio's "solution" concept is not even near to the concept of workspace, as solution is just parent folder to group one or more projects and give them some common CLR names and properties.
I'm using Eclipse for at least 10 years now... I got to this conclusion : I have same workspace for all projects that use same JRE and same APP server. I have different Eclipse versions, if I need some special tooling (Spring or CDI or PHP or some exotic plugin). All workspaces are located in my home directory.
You can paste / copy workspace to different computer, with same Eclipse version it works out of the box.
Simplified, a workspace is a special directory that is monitored by Eclipse: a change inside the workspace directory can trigger something.
For example, a Java file that will be saved will be compiled and might create error markers in a dependent Java projects. Changes made outside of Eclipse are visible inside Eclipse only after a refresh (assuming Window > Preferences: General > Workspace: Refresh using native hooks or pooling is disabled): instead of slow file accesses, Eclipse stores states of workspace files internally.
From a historical point of view, the workspace concept can be seen as a compromise between database and file system (in IBM VisualAge which can be seen as the predecessor of Eclipse the Java source code to be edited was stored in a database).
In addition:
Multiple instances of Eclipse can run concurrently, each with its own workspace.
Eclipse stores almost all preferences (Window > Preferences) in
the workspace (in the .metadata subfolder). Different workspaces can have different preferences.
The .metadata subfolder is also be used for caching to speed-up Eclipse.
I suspect that the target platform that is required to develop Eclipse with Eclipse (dogfooding) also played a role in the decision for the workspace concept (see also Eclipse bug 392652).
Think of a Java interface and a concrete class implementing that interface. It's similar for the Eclipse workspace and the underlying directory.
A workspace as a logical container for projects and configuration. That logical concept is implemented by a physical directory on your file system. The way it's designed, it would actually be possible (in theory) to implement a workspace using something other than a (local) file system (similar to what VisualAge for Java did, as referenced in #howlger's answer), although I don't know of any such implementation.
The point is, what you interact with while using Eclipse the IDE is a concept; it's best to not think about it too much as a filesystem directory. Doing so leads to some assumptions that won't always hold true, if you get deep enough into using it. Going back to the first sentence of this answer, you can sometimes get away with assuming a particular implementation of an interface, but doing so has hazards if you're not careful.

Where does Eclipse store projects / packages etc?

How do I tell eclipse on my desktop to open projects that are saved on my laptop without importing the project? I want to be able to save on one machine and pick up where I left off on the other. Thanks.
All projects are saved in the workspace (which saves additional meta data).
A simple solution for you would be to save the workspace on dropbox or similar and let eclipse load the work space from the drop-box folder.
Another option would be to use version control which is common in pratice (see http://en.wikipedia.org/wiki/Revision_control), e.g. git (github.com).
All of the details end up in the workspace itself. So the workspace needs to be in a location that is shared between the two machines.
Dropbox is a good option.
I would import the project into eclipse on my laptop as well as on my desktop, with the common dropbox folder as the workspace, so that everything is synced.
For instance, if I make changes to my code on my desktop, dropbox should automatically sync those changes. After that, when I open up the same code on my laptop using eclipse, I would make sure to go to my project explorer, click on the project and manually refresh (press F5). Be sure to refresh!
You can have a workspace on each machine linking to the same project files. The most convenient way is creating the project in a shared location (e.g. an external hard disk) rather than inside the workspace folder, then doing "import existing projects" on the other machine (with an independent Eclipse installation and workspace).
At this point you only need to keep in sync two Eclipse installation (same installations, removals and updates of plugins) and two workspaces (typically, you can set up one, export the configuration and import it in the other installation).
I would be uncomfortable sharing a workspace along with projects:
some settings might need to differ between workspaces. Common case: web proxy configuration.
Two workspaces can include different projects.
If you don't have exactly the same version of the same plugins, two Eclipse installations could fight to rewrite workspace settings to their liking.
Actually what you do it is stored in your workspace located in the user folder in the drive where OS is installed. You can find it simply here in your own pc
C:\Users\PCname\workspace\buky\bin
According to your scenario, I think the best option for you would be using a distributed version system. This way, you could have both projects on different machines under different local repositories (you don't even need to have a central repository or something similar), pushing changes as you work on them.
That being said, I would recommend you taking 30 minutes to read this Mercurial Tutorial.
The workspace saves this information, but it also saves a lot of other metadata that you may not want to share between different computers. Such as where dialogs are seen, what perspectives are open etc. If the Eclipse are of different versions, you may end up with the newer version converting the workspace to a later configuration and rendering it unusable to the older version.
The best way to share projects between computers is to use project sets. This will also work for sharing projects between different users. This in turn required a source repository, which is something you should always consider using.

Sudden weird errors on a project

Today I came to work, happy. But when I opened my Eclipse, I saw that one of my projects has errors.It's weird because it shows that it has errors only in the window bar, and not in the Navigator. I don't have any Java errors, this is a valid project that was fine all the time:
Some of the errors on the error log of Eclipse:
JavaBuilder handling ImageBuilderInternalException while building: SP_Procedure
Cannot connect to VM
File <SomeFile> has been skipped, problem while reading ('Resource is out of sync with the file system')
Unhandled event loop exception
Internal error
When I run an application from this project, I get a warning message but when I proceed, it works fine, but still. It's very disturbing and I'm not sure if it's harmless.
I tried to:
Restart Eclipse
Restart my machine
Clean projects and recompiling them.
Refresh projects
Pray
Nothing helped. What could be the problem? (I'm using Indigo Service Release 2)
The following nuclear option has desperation written all over it. But I have been where the OP has been with the Juno version of Eclipse.
Run a "Synchronize with Repository" and save all of your local updates to a different directory.
Delete the project. (Check the box to delete the contents on disk. Scary step, but that's OK, because you saved it in a different directory in the previous step, right?)
Read in a fresh project from the repository. It builds happily at this point.
Integrate your local updates.
Keep on praying.
Looks that one unused JAR was deleted, but for some reason, I didn't get errors in any file, even in the files that imports this JAR! So what I did was restoring this JAR, delete unused imports and deleted the JAR again.
I've found this error after two days of navigating on this project on each file.. This is weird that Eclipse didn't recognize that1 this is an error, and throw many unrelated errors such as:
Cannot connect to VM
File has been skipped, problem while reading ('Resource is out of sync with the file system')
Unhandled event loop exception
Is this a bug in Eclipse? (All errors and warnings are enabled!)
1 As seen in the image in the question..
A class from the list of imports for the file seems to have moved out or the jar file containing the class is missing.
Expand the imports section and check if you find some classes that are missing but have been imported.
Though it is a pain, sometimes the easiest solution is to back up all your projects (either in a repository or somewhere else on your computer) then uninstall and reinstall eclipse. No it's not fun, but it should reset eclipse so everything works again. The downfall though is that you have to reconfigure eclipse to any special settings you had/reinatall any extra functionality currently installed (eg. android add-on) and reconnect to any repositories you have. While punting isn't fun, it can be effective... I hope you don't have to resort to this though.
I have went through that problem a lot of times, and tried everything you tried. Rebuild, recompile, refresh, remove and add JDK, remove and reinstall Eclipse... nothing worked
The only thing I concluded is that the workspace metadata was corrupted.
What I did (every time it happened) was
Create an empty workspace
Import -> existing projects into worskpace
Mark the "copy projects" (else it will only link them)
Wait for the copy, and start working with the new workspace
If you work with SCM systems (Git, SVN, etc), making a full checkout will do the trick too, but the worskpace import will let you retrieve those changes you didn't get to commit (if any).
It's a little painful if you have somethings already set (like JDK names, servers, etc), but then I realized it was faster than keep searching how to fix the workspace
Regards!
PS : I've been working with Kepler lately, and everything works fine till now
Click Window -> Show View -> Other -> General -> Problems
This view will show you what is wrong.
Did you, by any chance, update your virtual machine outside of Eclipse? I can't help but feel that we're both missing a finer detail here. I just keep seeing "cannot connect to VM" and thinking that it's a major clue.
Have you tried running anything from the terminal? Does it work there?
If so, do you know where your current edition of Java is located? Is Eclipse looking somewhere else?
Is this exclusive to one project? Do you use any additional libraries to the JDK?
Maybe try this for Resource is out of sync with the file system error:
Right click project in Eclipse Package Explorer
Close Project.
Right click project in Eclipse Package Explorer
Open Project.
Other things not mentioned:
project properties > java build path, see if any of those tabs got changed, local file got moved? read/write permissions on some file you are linking to?
project properties > java compiler, see if workplace settings have changed? maybe under errors/warnings, you can systematically set them to 'ignore' until the error goes away to determine what type of error it is?
maybe update some of the eclipse plugins?
I saw something like this happening for a number of reasons. Mainly because of validation in files other Java source code. See if you are validating XML for instance.
Right click your project and chose Properties (Alt+Enter) and Validation to see the related configuration.
As for the danger, I lived with those marks for ages and nothing wrong ever happened.

Eclipse plugin development: Is plugin update or uninstall/install really clean?

While developing Nodeclipse, I found that some bugs don't arise immediately but after some time, when combination of updates, restarts happens.
Is plugin update or uninstall/install really clean?
I develop and use installing for update, then use newer version until I got time/idea to improve. However as said above I ran into situation when Eclipse behaves differently after the new feature have been used for several days.
Is there some information that must be read about plugin install life-cycle, that mentions some not so evident behavior.
UPDATE: Some problem were in Autumn 2013 when we were switching to tycho build. Also around that time Eclipse Kepler 4.3.1 was released.
No, they are not "clean". Moreover when you do uninstall, no files are deleted, Eclipse would just prevent plugin from loading on the startup.
If you really want to remove the plugin you need to
Uninstall it via UI
Delete the plugin files in the file system
Remove plugin settings from workspace or create a new one.
Here is some interesting info for you:
There is no mechanism within Eclipse to permanently and physically
uninstall a feature and its plug-ins. The process to physically and
permanently remove an undesirable feature and its plug-ins is a manual
process that should be done when Eclipse is not running. In order to
do, you will have to manually remove the files there associated with
the feature from the eclipse/features directory and its plug-ins from
the eclipse/plugins directory. Be very cautious as to which files you
delete, and always have a backup of your Eclipse directory. If you
remove the wrong files from these directories, you may have quite some
trouble restoring your Eclipse to a stable state. Therefore, unless
your hard disk storage capacity is extraordinarily limited, it is
recommended that you simply leave the physical files in place.
Note that when manually removing plugins as described above, it is
likely that some metadata will still cached by Eclipse. This can lead
to problems later on. Running Eclipse with the -clean option may help
with that, as it causes Eclipse to clean the cached metadata. See the
Running Eclipse help page for details about this option.
Source: http://wiki.eclipse.org/FAQ_How_do_I_remove_a_plug-in%3F
You cannot do this ideally, because the plugins designed for eclipse leave their temp access files even if they are uninstalled, to do so, you will have to follow the steps:
Uninstall the Plugin: You can use the Eclipse UI directly. Go to Help > About Eclipse > Installation Details, select the software you no longer want and click Uninstall.
Delete the Present temp Files in the System, make sure to re-check the dependencies(Note: Removing Dependent Plugins might cause Eclipse to stop Working).
Remove the plugins from the workspace, or in short you can re-configure a new workspace.
This would be removing the plugins, but removing its traces manually.
ref#Link

Eclipse keeps running my old web application

OMG - what is going on with Eclipse (3.3 Europa) - has anyone come accross this problem (bearing in mind I have been messing about with uninstalling different Tomat containers and installing others - but anyway thats another story)
When I change a line of code or remove a class within my project - when I come to debug - it actually goes to a line that is commented out and runs that line regardless!!!! e.g.
//System.out.println("you should not be able to read this!");
UPDATE: This can be solved by setting Project -> Build Automatically (see answer below).
REMAINING PROBLEM:
Eclipse is not keeping my hot deploy folder current with the latest changes to my project:
I found out to my horror that some old remenants of my project are 'hanging around' in the folder that I think Eclipse uses for hot deploys or something
C:\myJavaCode.metadata.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\myWebApp
basically it is not actually copying accross any changes made in the classes of my working dir!?!??
...anyway - in order to keep my project up to date - I have to modify this folder too - TOTALLY UNACCEPTABLE - as you can't develop in this way - it would take you eons! Anyway, if anyone can help explain to me what stupid thing I have done to get me in this mess and how I can get out of this mess - I would really appreciate it.
Have a look at:
Windows>Preferences>Server>Launching...
and:
Project>Build Automatically
maybe you accidentally disabled the auto-deploy features.
I had a similar problem, only without the added complexities of a web app. I'm just running a JUnit test and it's running the old code. I went into Configure Build Path, on the bottom of the Source tab, and looked at Default Output Folder, which said myproject/bin. The Package Explorer doesn't even show a bin folder, but when looking at the file system there's a bin folder there. I deleted the bin folder, refreshed the package explorer tree, and it worked. This behavior was in Helios and occurred with AND without Build Automatically selected...looks like a bug to me.
Dave
A super-silly question: Does all your webproject and related projects compile correctly?
Also check your output folder for classes (Project Properties -> Java Build Path -> Source Tab) then go to your filesystem and check permissions and modification dates.
Hope this will help you.
Probably the easiest way to get past this is to define a new server.
Right-click in the Servers window and select New, or when you do 'Run On Server' select Manually define a new server. You can have multiple servers defined using the same Tomcat runtime (they'll all have separate configs and deployment directories defined by -Dcatalina.base=...), but don't run them at the same time unless you change the ports they're listening on.
The new server will use a path like
<<yourEclipseWorkspace>>\.metadata\.plugins\org.eclipse.wst.server.core\tmp1
for the Tomcat conf and webapps directory.
Try running on this server. If it works, you can compare settings with the old one,
maybe try deleting the app from it and re-deploying, and figure out what you might have done to cause the problem. Or just delete the original server config.
As far as your second problem, I'm not sure. I'd try a new server config first, get it working, stop the server, do a 'Clean' on your project, delete anything in the tmp1\work\Catalina directory, and restart the server (you could remove and add your project to the server again too to be really clean).
Check the console messages too to make sure there were no errors related to this.

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