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I am trying to use Eclipse, Subversion and Maven for my projects and everyone is telling me never to check in the following files:
target/
.classpath
.project
.settings
But if I dont check them in and some other project checkouts the project from within Eclipse, Eclipse does not know what type of project it is.. Are we doing something wroung?
How do you work?
Eclipse has a plug-in for Maven; I believe it is called m2eclipse. After having it installed you can select Import from Maven project and select the pom.xml which will import your project to eclipse even if .project and .settings are not present. So there is no need for you to commit them to svn. This comes with the advantage of IDE neutrality; other members of your team may use Intellij IDEA or NetBeans without any concern.
Also Maven has a plug-in for eclipse; you can go where pom.xml is located, open a terminal and type mvn eclipse:eclipse and it will automatically generate .project and .settings.. However the first option is more recommended.
I had the same issue with eclipse, maven and git, so maybe it is helpful for you:
Try to setup your repo in svn and check it out, but don't import it.
You have to import the project over File -> Import -> Existing Maven Project into your workspace.
The last step is to share the project. Rightclick -> Team -> Share -> SVN -> and set the existing one as repo.
That's the way I handle this in Eclipse. Hope it's clear enough?
Btw you should not check in these file, because classpath and so on could be different on other machines.
I check in .classpath and .project but not very often. You do have to make sure that everyone who is working on the project has versions of eclipse that are close enough (including the particular plugins and eclipse features included). Sometimes you can get by with very different versions of eclipse if you make sure almost nobody checks those files in and everybody just mostly compares and manually updates those files from the version control when they are updated.
If you don't check them in, everybody has to create an empty project and then load the source files (and all the version control files or folders) into the project. If you are careful you can copy in those two files and then fool with the options settings to make them match.
Note that Maven helps a lot with this as it takes care of most of the content of the .classpath file.
The main reason not to check in those files are that the IDE's will very likely make changes to those files to suit your local dev environment. Which will probably cause conflicts and thus "broken" projects if everybody is committing their versions all the time.
That said, eclipse should have decent maven integration via the m2eclipse plugin (which I believe might be baked in by default these days).
Part of the idea behind Maven is exactly this - reproducible builds cross platform, cross IDE etc etc - so IDE specific files like that should not be required to build the project.
Importing the project with the m2eclipse plugin should sort things out nicely.
If you mean the other members check out the project and it doesn't work for them, they can check out the maven project separately without using eclipse and then import it into eclipse as an existing maven project using the m2eclipse plugin. This works cleanly without any problems (for me at least).
if everyone in your team is using Eclipse and it is agreed that the project will never use anything else, you may as weel check those files in. but it will make things kind of irritating if someone uses IntelliJ, Netbeans of other tooling or has his Eclipse very customized.
It depends.
Maven documentation explicitly says something like "Do not check in .project/.classpath/.settings/ because they can be regenerated from pom.xml". The later part of the sentence ("they can be regenerated") is not true, so the first part of the sentence (the advice) may or may not be OK, depending on the circunstances. Not every bit of the Eclipse configuration can be regenerated from the pom.xml, so my opinion is that the decission is based on a tradeoff between how much gain you get from it and being tied to the particular IDE.
So it depends.
For "community projects", where usually each developer will use different IDEs and different versions of the IDE, I would recommend not to check in those files. Otherwise, it would be a pain for developers not using your IDE and your version of the IDE.
For large "corporate project", IDE and IDE version are not free to be choosen by the developer but firmly dictated by the project management. So are dictated things such as compiler(1), code formatting, validating rules, warnings-and-errors configuration, custom in-house plugins configuration and many others. Many of those things cannot be set in pom.xml (nor should they because Maven is not and IDE, but a building tool). So in this case I would recomend to check in those files and blame the developer who complies, because he is trying not to follow the dictates.
(Notice that in this case I intentionally used words such as "dictate" and "blame" because the project management of a corporate project has not only the right but also de duty to "dictate" and "blame")
In the opposite side, for one-person projects, you do not have to worry about your colleages, so go check them in.
But the key is that you have to know your circunstances and the consecuences and decide yourself.
(1) No, "maven.compiler.source" is not the compiler to be used.
I inherited a Java project in the form of an Eclipse project. After changing the Tomcat configuration (from v6 to v7), Subclipse prompted me to commit the following files:
.classpath
org.eclipse.core.prefs
org.eclipse.common.project.facet.core.refs
org.eclipse.common.project.facet.core.xml
Will commiting them help my team members or will it mess with their workspace?
What is the best practice approach to this?
Generally speaking, you should check-in (and commit after changes) everything that does contribute to the build AND is not re-generateable by re-building completely AND is workstation-specific. (The implications of this statement depend on your build process/procedure, which is intended.)
This implies you should exclude everything that is re-generated upon full build etc. so it is not checked in (and not offered for check-in).
As a general rule, you should avoid committing files that contain user preferences, and project details that that Eclipse and/or your plugins can regenerate.
But in some cases things are a bit murky. For instance, the .classpath file can be the primary source of the Eclipse build path; e.g. if you have JAR files in your project tree rather than using Maven. (With Maven, the m2eclipse plugin generates the .classpath file from the dependency information in the POM file, and hence the file should not be checked in.)
Also, some of the facet stuff is borderline. For instance, in projects with JSPs and Javascripts, I have found it essential to change the facet properties to disable broken validators. And there's a good case for treating those changes as part of the project rather than as personal preferences.
Separation of group / project preferences from personal preferences is one area where (IMO) Eclipse is seriously deficient.
It is better not to commit those files as paths/settings may differ on different workstations.
You may wanna use some build tool to overcome this. (eg. Maven)
As if any of the team members are not using eclipse (using some other ide) , those files have no meaning for them.
If everyone commits different IDE settings, imagine what kind of mess it can cause.
EDIT:
More explanation;
I have worked in teams that people used NetBeans, Eclipse, IDEA...for a really long time and it is not really an option for them to change the IDE. It will only affect the productivity of that person.
When people get used to their IDEs they learn shorcuts, they know where to look for some functions (refactor/generate getter setter/implement override required methods....) so if you force them to use some other IDE it will just make things harder for them and slower for the overall process. IMHO and from my experience having a flexible codebase is always good. I am an eclipse guy and probably would not want to work with any other IDE as I know lots of shorcuts which makes thing real quicker/easier for me and those shorcuts are different on different IDEs.
All IDE files can be regenerated automatical by the IDE itself probably in just a couple of clicks.
And my current project has 3 developers, each using different IDEs eclipse(me), NetBeans, IDEA without any problems. I dont want to see IDEA or NetBeans config files which makes no sense for eclipse when I check out the source from repo. Likewise for them as well.
Yes, though do make sure that paths are relative in the workspace rather than absolute paths. Having these files in the workspace allows members of your team to work in the same environment as you are. It also makes setting up a new development environment much easier: you just check it out of source control and in Eclipse use 'Import... > Existing Projects into Workspace'
As #adamdunne mentioned, these files can contain environment specific paths. However it if you are careful to make sure paths are relative within your workspace, by using variables and by not importing external jars, i.e., by only including jars from projects in the workspace, then you should be okay. In my workspace we check in those files and have had a lot less issues setting up dev. environments since.
I work in a project where we commit the .classpath file since it is very useful that all developers use the same :) If you only use dependencies inside your workspace, this file uses relative paths and thus should be same on all machines. Even if this file might not be necessary to build (with ant e.g.) it´s very convenient to synchronize it.
In contrast the org.eclipse.core.prefs stores (afaik) project-specific, but personal preferences of developers which I would not check in.
With the facets I didn´t work yet in a real project, so I can´t tell. But in general, I think it depends on the information in the file and on the way you work.
If you are unsure, just try it. If you get conflicts in these files all day this is a hint you may not be on the perfect way.
These files can be very useful to share configurations between developers. The alternative is to either use Maven (which is a huge task for an established project) or to have constantly-outdated step-by-step instructions and new developers taking half a day until they can even build the project.
However, you should take care to ensure that these configurations are portable, i.e. contain no local paths. This can be done via the use of relative paths within the workspace, eclipse path variables and user libraries.
What we've done is ignore these files, as they may mess up the workspace of others on the project.
Ignoring them also makes your project cleaner, which I always like.
These files can contain environment specific paths so I would suggest not checking them in. On my current project we use ant scripts to create the project and do the initial checkout of all our code.
I'm coming from the .NET world where Visual Studio is pretty ubiquitous. VS has a .sln file which pretty exhaustively describes a project, including where to find source files, dependencies, etc.
Now I'm doing some java coding in a team. My problem is this: I'm using intellij and others are using eclipse (while others could be using some other IDE). Is there a standard project description file that can be shared among IDE's? I obviously don't want to put my intellij specific files to source control. So what I'm looking for is a standard that pretty much any self-respecting IDE would recognize which you could point it to and it would be able to interpret the project structure, how to find dependencies, the class paths, etc.
Maven should be able to do it (a project build manager and source control overlay), but alas, there is no standard project file. There are Maven plug-ins available for all the major IDEs. http://maven.apache.org/guides/getting-started/maven-in-five-minutes.html
Note quite. But you have a "way out". You can use Maven2. It has a unified pom file which contains all:
source folders (note: maven imposes a default convention on those, but they are still configurable)
compiler level
dependencies
build steps
etc..
(Of course that would require to install the maven plugins for both IDEs)
Another option would be to force either of the IDEs and commit their proprietary descriptors.
As others have posted, Ant and Maven are pretty much the de facto project spec utilities in the Java world. Those are both generally easy to learn -- a fair learning curve, but nothing dramatic -- and are pretty powerful. You could speak to your team members or leader and see how they've dealt with it -- I'm sure it isn't a new problem.
Aside from that, a lot of development teams (in my experience, at least) try to avoid putting project files in source control. The developers are required to basically create their own projects in whatever IDE they're using. It makes getting started on a project a little more difficult for a developer coming fresh into an existing project, but it also helps the developer get a little better acquainted with the project.
At my shop (very, very small team), we use Eclipse, but we still have to manage the workspaces (similar to VS solutions, but not quite the same) ourselves. I've created some Ant scripts for use on our continuous integration server, and that won't necessarily keep problems from arising, but it helps make them more obvious when they do.
There is no such standard project description file as far as I know. But intellij is able to take an eclipse and convert to an intellij project. Also you could look at maven.
There is not one. You could switch to an build system using ANT (similar to Make) but that has pitfalls of it's own. You will get the most mileage if you and your team standardize on an IDE though ...
I think what you want here is for a developer using Eclipse to edit the project settings and have those changes reflected in IDEA for some other developer. If that's the case, then Maven is what you want. IDEA 9.x has great support for Maven, and so does Eclipse. If a developer that uses Eclipse edits the dependencies in the Maven project files (pom.xml files), then IDEA can import the files and change it's project settings.
RE: ANT vs Maven - In this respect (syncing project settings) ANT build files won't work because they are imperative (script-like) rather than declarative.
Maven should be the preferred way but most IDE's now days support some kind of ant based project which is what most of the IDES use internally. Usually called free-form projects.
I'm not a Maven fan myself. I'd recommend Ant long before Maven.
If you're using IntelliJ, I'd argue that it does have a pretty standard idiom. And since it can import any Eclipse project file, you'll be on safe turf laying things out as IntelliJ does it.
I don't check in my IntelliJ project files, but the /src, /lib, /test, /resources etc. are all fair game.
The true answer should be that your team should huddle up and come up with a standard layout that you agree on regardless of IDE. You've got to check code into SVN sometime.
Your question is interesting to me, because I'm trying to go in the other direction (Java->C#, IntelliJ->Visual Studio), and I'm having trouble doing the mapping in the other direction.
I think it's just part of learning a language and its native IDE. I find that it's best to find an experienced guide.
One problem you'll have is that the .NET universe is isotropic (all things Microsoft), where even your small corner of the Java universe is heterogeneous (IntelliJ and Eclipse and NetBeans). You're less likely to find one true answer for all of Java.
I'm soon going to check in the very first commit of a new Java project. I work with Eclipse Ganymede and a bunch of plug ins are making things a little bit easier.
Previously I've been part of projects where the entire Eclipse project was checked in. It's quite convenient to get the project settings after a check out. However this approach still was not problem free:
I strongly suspect that some Eclipse configuration files would change without user interaction (from when I used Eclipse Europa), making them appear as changed (as they were changed, but not interactively) when it's time to do a commit.
There are settings unique to each development machine as well as settings global for all developers on a project. Keeping these apart was hard.
Sometime if the Eclipse version was different from others Eclipse would get angry and mess up the project configuration. Another case is that it change the format so it gets updated, and if commited messes up the configuration for others.
For this specific project I have another reason not to commit the project files:
There might be developers who prefer NetBeans which will join the project later. However they won't join within the coming months.
How do you organize this? What do you check into versioning control and what do you keep outside? What do you consider best practice in this kind of situation?
At a minimum you should be check-in the .project and .classpath files. If anybody on your team is hard-coding an external JAR location in the .classpath you should put them up against the wall and shoot them. I use Maven to manage my dependencies but if you are not using maven you should create user libraries for your external JARs with with a consistent naming convention.
After that you need to consider things on a plug-in by plug-in basis. For example I work with Spring so I always check-in the .springBeans and likewise for CheckStyle I always check-in the .checkstyle project.
It gets a bit trickier when it comes to the configuration in the .settings folder but I generally check-in the following if I change the default settings for my project and want them shared with the rest of the team:
.settings/org.eclipse.jdt.ui.prefs - it contains the settings for the import ordering
.settings/org.eclipse.jdt.core.prefs - it contains the settings for the compiler version
In general I haven't noticed Ganymede modifying files without me modifying the project preferences.
I recommend to use maven so that the entire life cycle is outside of any IDE. You can easily create an eclipse project with it on the command line and you can use whatever you want, if it's not eclipse. It has it's quirks but takes out a lot of bitterness when it comes to dependencies and build management.
In our world, we check in the entire Eclipse project and the entire parallel but separate Netbeans project. Our motivations for this were entirely focused on "when I do a checkout, I want a functional configuration immediately afterward." This means that we had to do some work:
Create runnable configurations for each primary IDE (people like what they like). This includes main class, working directory, VM parameters, etc.
Create useful start up scripts for all of our relevant scenarios.
Create edited datasets that don't cause the checkout to take too much longer (it's a big project).
This philosophy was worth cash money (or at least labor hours which are almost more valuable) when our new hire was able to check out the project from Subversion into Eclipse and immediately run a functional system with a (small) real data set without any fuss or bother on his part.
Follow up: this philosophy of "make the new guy's life easier" paid off again when he changed IDEs (he decided to try Netbeans after using Eclipse for quite a long time and decided to stick with it for a while). No configuration was required at all, he just opened the Netbeans project in the same directory that Eclipse had been pointing to. Elapsed switchover time: approximately 60 seconds.
I only ever check in things are done by humans, anything else that is generated (whether automaticly or not) should be easy to regenerate again and is liable to change (as you've stated). The only exeption to this is when the generated files are hard (requires alot of human intervention ;) ) to get it right. How ever things like this should really be automated some how.
Try to port your project to a build system like maven. It has everything you need to get the same experience of the project on every machine you use.
There are plugins for just everything. Like the eclipse plugin. You just type "mvn eclipse:eclipse" and the plugin generates your entire ready to work eclipse project.
To give the answer to your question. Never check in files that are not being used by your project at any time in the development cycle. That means that metadata files like eclipse properties etc. should never be checked in in a SCM.
I like checking in the .project, .classpath, and similar files only if they will be identical on any Eclipse user's machine anyway. (People using other IDEs should be able to check out and build your project regardless, but that issue is orthogonal to whether or not to check in Eclipse-only files.)
If different users working on the project will want to make changes or tweaks to their .project or .classpath or other files, I recommend that you do not check them into source control. It will only cause headaches in the long run.
I use IntelliJ, which has XML project files. I don't check those in, because they change frequently and are easy to recreate if I need to.
I don't check in JAR files. I keep those in a separate repository, a la Maven 2.
I don't check in WARs or JARs or javadocs or anything else that can be generated.
I do check in SQL and scripts and Java source and XML config.
I'd suggest having the actual project files ignored by the version control system due to the downsides you mentioned.
If there is enough consistent information in the project settings that there would be benefit from having it accessible, copy it to a location that Eclipse doesn't treat as special, and you'll have it available to work with on checkout (and copy back to where Eclipse will pay attention to it). There is a decent chance that keeping the actual project files separate from the controlled ones will result in loss of synch, so I'd only suggest this if there is clear benefit from having the settings available (or you're confident that you'll be able to keep them synchronised)
In our case, we used to check in the project files (.project and .classpath) to make it easy for all developers to create their project workspace. A common preferences file and team project set were located in source control as well, so creating your workspace was as simple as import preferences and import team project set. This worked very well, but does rely on everyone having a consistent environment, any customizations would have to be applied after the basic workspace is created.
We still do this for the most part, but Maven is now used so of course dependency management is handled via Maven instead. To avoid conflicting information, the .project and .classpath were removed from source control and are now generated via maven goals before we import the team project set. This would easily allow for different environments, as you would simply need scripts to generate the IDE specific portions based on the Maven configuration.
PS-For ease of maintenance though, I prefer having everyone use the same environment. Anything else inevitably becomes a full time maintenance job for someone.
Netbeans 6.5 has an improved Eclipse project import which is supposed to sync changes from Netbeans back to Eclipse: http://wiki.netbeans.org/NewAndNoteWorthyNB65#section-NewAndNoteWorthyNB65-EclipseProjectImportAndSynchronization
Don't. Only check in the source code of your projects.
As a response to:
"There are settings unique to each development machine as well as settings global for all developers on a project. Keeping these apart was hard."
Eclipse offers a number of ways to keep local settings manageable: Java Classpath Variables (Java > Build Path > Classpath Variables) are one, 'Linked Resources' (General > Workspace > Linked Resources) are another http://help.eclipse.org/stable/index.jsp?topic=/org.eclipse.platform.doc.user/concepts/concepts-13.htm Creating a README that states which settings to set before building/running the project works pretty well in my opinion.
Now how to make sure your continuous build system understands the changes that were made to the eclipse settings, thats another issue... (I have a separate build.xml for ant that I keep up to date by hand)
What is the best way to allow a team of programmers to use Netbeans, Eclipse and IntelliJ on the same project, thus eliminating the "which IDE is better" question.
Which files should or should not be checked into source code control?
I think the best way is to make the build process independent of IDE. This means that your project should not rely on any IDE-specific files to build, but rather use an external build system, like Apache Maven, Apache Ant, or even make or custom scripts. Maven is supported by most popular Java IDEs, either directly or via plug-ins.
If you don't want to use an external build systems, you should at least make the project as easy to set up as possible (i.e. by having standard folders for shared libraries and other dependencies). When I have working on teams with multiple IDEs in the past, I spent by far the most time on resolving dependencies as the prerequisites for building the project changed over time. In the worst case you may even end up with developers not bothering to get the latest version from the version control repository, since they think setting up the new project is such a hassle.
If your project has many library dependencies, I think its a good idea to make these available in binary form in the version control repository. That way people don't have to resolve all the dependencies of the dependencies and so on just to build a single project. This does however require that you have someone responsible for keeping the "official" binaries up-to-date whenever they change. (This is pretty much the same philosophy used by the Maven repository, but the principles can be applied manually even when not using Maven.)
Well, that's a pretty self-answering question.
The files to not check into source control are files that have to do with the IDEs themselves.
Leave it to the developers to generate these files.
If you use Maven, it can generate the files such as Eclipse's .project and .classpath for you. Eclipse in general is very easy to use with a basic file structure (with the new Java Project option).
I think Maven has Netbeans support as well, not sure about IntelliJ though.
Maven's site is maven.apache.org.
For each IDE that has more than one developer, check-in all the supporting files. Why re-invent the wheel at every desk.
I have done this with many different IDEs, and I have yet to see a filename conflict.
In fact, even when only a single developer uses a particular IDE, it is to his/her advantage to version the supporting files, for the same reason that you version the other files in your development environment: history, diffing, comments, etc.
For Eclipse, that would be .classpath and .project files.
My team uses Maven, and developers are discouraged from checking in Eclipse-specific files. Because they can be generated from Maven, these files are redundant.
Also, checking project-specific files seems like it would save time, but it usually winds up being a pain because of variations in different developers' workstations, resulting in wasted time resolving conflicts in the IDE-specific files. The only way to get around that is to force everyone to set up their environment the same way, which goes against the IDE-agnostic approach.
There are many considerations when using multiple toolsets within the same project team. For example, my team has Java developers using IntelliJ and most of the front end (JSP/CSS/HTML) developers using eclipse. We are in the process of migrating the Eclipse users to IntelliJ because of some IntelliJ plugins that we have developed that provide extended support for our environment. We're not going to develop the plugins for multiple platforms, so we are standardizing on IntelliJ across the board.
In terms of specific files, I can speak to IntelliJ. We have checked in our .ipr files and our .iml files. Do not check in .iws files. If you also have Eclipse users, configure your IntelliJ project to read/store dependency information in the .classpath file and commit that to your VCS.
We intentionally support multiple IDEs from the same SVN repository. Our thinking was that we want to ensure that, if a new person joined the team or someone had to start working on a new machine, we wanted them to be able to checkout the codebase, import it to the IDE and immediately have a work-able configuration.
What that means on the developer end is that they should not commit their changes to the IDE files. Everything else (e.g., src, test, lib and so forth) becomes the set that we normally update and commit every day.
The side benefit is that we have completely eliminated the IDE wars here: Netbeans and Eclipse people live in perfect harmony (looking askance at the IntelliJ people, but hey... ;-).
For more comments and answers on this topic see this question (How do you handle different Java IDEs and svn?)
We rename our IDE files for checkin with an extra extension .deletethis or similar. When a new person checks out the project, they simply strip off the extra extension and are good to go. This way we avoid source control conflicts with the project files as people tweak their environments. And you don't have to worry about educating new developers to not check in those files.
Typically, I would consider this a bad idea. I'm not sure what kind of environment this is (perhaps open source?), but it would really suck to support multiple IDEs. One thing I would recomend if this is unavoidable, would be to standardize your builds in ant scripts. If you have a large set of dependencies, this may be the easiest way to get a predictable build across all platforms.
If one of the IDEs happens to be RAD (based on eclipse), there is an entire folder called .settings that you would not want to include in the SCM.