Can Ant detect if a project is closed in Eclipse? - eclipse

We're using Eclipse on a flat multi-project set-up. Ant builders are set up on each project to create jars as needed; the ant files are used to manually kick off junit tests, create junit reports, etc.
One project is set up as a "master build" project, from which one has a convenient single ant target "test-all", which invokes the test target in all the other projects. This works, no problem.
The challenge is, that to some developers, certain projects represent optional components that aren't relevant to their immediate work task. So they close these projects to create some time-savings when doing things like clean and rebuild the whole workspace. This is fine, Eclipse ignores the closed projects as intended.
Problems occur when one goes to the "master build" project, and runs the ant test-all target. As you'd expect, it goes and tries to run the tests for all the projects, not just the "open" ones.
Any easy way to make the ant script smarter when running in an eclipse environment to know about "closed" projects, so I could make it ignore those?
Sort of adding an "unless=${CLOSED.UNDER.ECLIPSE}" type of ability to my ant files.
many thanks.

Related

what is the right way of importing a maven project in Eclipse and run it as a Java project?

I don't understand exactly what is the way of working with maven projects in Eclipse.
The problems I have are often with projects I download from github. If I set the project myself it usually work, so I think I'm doing something different from the majority of people.
I'll try to detail a specific case:
I clone a repo, let's say: https://github.com/spring-guides/tut-spring-boot-oauth2
In Eclipse I import "existing maven project"
The project has a "Maven nature" as indicated by M on the folder icon
I try to run java class with main from Eclipse. First strange thins is that the "Run As" menu doesn't have "Run as a Java application"
I have to configure the configuration manually. Now it runs, but strange things happens, like I can't edit the file as the "content assist" throw errors instead of giving the normal assists.
I notice that the project has no "source folder". So my first instinct is to add a Java nature or select src as source folder
So I add Java nature to the project. This is a disaster. It can compile anymore as it can find packages. All classes have errors. I try to play around setting source folders on /src or /src/main/java. Sometimes I fix the errors but I can't run (and now I have run as Java application) but when I run it can't load the class
So in the end, I'm a bit confused and I don't know if I explained clearly what I'm doing.
I think I would like to know in a simple way how people are doing it, rather than trying to correct my steps as I'm probably creating a mess myself.
Any help or suggestion welcome.
I'm using the last version of eclipse. I don't know which other tool's versions are relevant.
P.S. I also refresh,restart,clean rebuild the project often after touching things...but it doesn't get better
Maven is a build (management) tool. Simply spoken, its task is to create a JAR that can be used as a dependency/library by other projects or when running java -jar ....
Running a project's code isn't part of it (apart from unit and integration tests code and by using non-default plugins for special situations). Running code is part of Eclipse (or any other IDE) with its Run Configurations.

Working on an Eclipse project (using Builders) in IntelliJ

I've recently been tasked with working on an existing eclipse project that makes use of Builders to run Ant tasks under given conditions. I've never heard of Builders before yesterday, and I'm having difficulties getting the project to work in IntelliJ.
First of all, I would like to know if there is a way I can effectively trick Ant into running from a different base directory than what it already does. Consider the following screenshot from Eclipse:
Here, project A is running an Ant task in a local build file that extends a build file from project B. As you can see from the Base Directory setting, it is different from that of A. When I try to run the task from this build file in IntelliJ, I get build errors because certain directories do not exist in the folder for project A -- they are located in project B.
Secondly, this Builder is set to trigger on Manual Build and Auto Build, but my understanding is that this only triggers if the project the builder is attached to gets built. As far as I can tell, in IntelliJ, I can set an Ant task to trigger before or after a build, but it seems like this will be for the whole project, instead of just the relevant module that represents this Eclipse project. Is there a way I can make it only apply to a given module, or will I have to trigger it for changes to all modules?

Keeping Eclipse project dependencies in sync with an external build system

Here is the situation. A development team has a large number (hundreds) of Eclipse projects. The code is very much in churn - new projects are being created; projects are being renamed and project dependencies are constantly changing. The external build system is ant. It is proving extremely challenging to keep the dependencies defined in the ant build files in sync with the state of the world in Eclipse. The external ant build needs constant changes to keep up. For various reasons, using ant as the default builder in Eclipse is not an option. The developers want to continue using Eclipse as the build and edit environment for local use.
Question: Is there a tool which will allow a single set of dependencies to be maintained which can be used by Eclipse as well as an external build system like ant?
I have heard of Gradle but never used it before. Would it make sense in this context? I am pretty sure Maven wouldnt work for what is needed
The typical workflow should be:
1. Developers continue working as they currently do - creating and changing Eclipse project dependencies at will and using the default Eclipse builder to compile and test locally.
2. Some mechanism exists by which these dependencies can be carried into an external build system like ant and an external continuous build triggered on every checkin.
Appreciate your feedback - thanks!
We have been quite successful at using Gradle to tackle a similar problem. Here's the outline of the setup
Each project contains a build.gradle that defines project specific dependencies and tasks (may even be empty).
A special master project contains build.gradle that sets up common dependencies and tasks for child projects, and/or injects settings pertinent to a group of child projects.
Logically master project is the parent project, but it exists as a sibling folder so that Eclipse can be more comfortable with it.
Gradle contains a built-in Eclipse plugin which allows generation of Eclipse settings files for each of the projects from the dependencies information (including inter-project dependencies). It works nicely for simple projects, and as for more complicated ones Gradle allows you to tinker with the settings files, so you can do pretty much everything. From here you have two options:
Not to store Eclipse settings file in the repository and call the generation task every time you do a fresh check-out (I prefer this option).
Tell Gradle to use custom variables to make it generate generic settings files which can be checked-in to the repository. You'll then only need to run the generation task when dependencies or other configuration changes.
(Optional) It's a little tricky, but you can make Gradle parse existing project ivy.xml files and set up dependencies from there. I had some success with this, although I would recommend converting dependencies into Gradle format for more flexibility.
Continuous build system integrate with Gradle very well (same as ant). If you are using Jenkins (Hudson) there is a Gradle plugin.
The advantage of using Gradle is that it scales pretty well, and you can support other IDEs like IntelliJ or Netbeans at the same time without much effort (unless you have lots of crazy custom settings). An advantage and a disadvantage is that Gradle is a powerful build system which requires learning Groovy and Gradle DSL which may take some time to acquire. Also the documentation is awesome.
Gradle has a very active community with the sole purpose of tackling exactly this kind of problem.
Hope this helps, and best of luck!
How about parsing the .classpath files, generate a dependency tree and start building from the root. What you need is a convention on the layout of your projects or an generic (ant-) buildfile that could be changed in each project, if needed (e.g. different project layouts). I´m not sure if Eclipse Tycho could be used for that, since it´s a maven plugin(s) to build eclipse plugins or projects. But it´s able to resolve the bundle and project dependencies against maven repositories and eclipse update sites.

How to get Eclipse to create bin/main and bin/test

I want my Ant build to take all Java sources from src/main/*, compile them, and place them inside bin/main/. I also want it to compile src/test/* sources to bin/test/. I wan this behavior because I want to package the binaries into different JARs, and if they all just go to a single bin/ directory it will be impossible* (extremely difficult!) to know which class files belong where.
When I go to configure my build path and then click the Source tab I see an area toward the bottom where it reads Default output folder: and then allows you to browser for its location.
I'm wondering how to create bin/main and bin/test in an existing project without "breaking" Eclipse (it happens). I'm also wondering that if I just have my Ant build make and delete those directories during the clean-n-build process, that Eclipse might not care what the default output is set to. But I can't find any documentation either way.
Thanks in advance for any help here.
In Eclipse, you can only have one output folder per project for your compiled Java files. So you cannot get Eclipse to do the split you want (i.e. compile src/main to bin/main and src/test to bin/test).
You can, if you want, create two Eclipse projects, one main project and one test project, where the test project depends on (and tests) the main project. However, in that case, each project should be in its own directory structure, which is not what you are asking for. But this is a common approach.
Another way, which I would recommend, would be to not mix Ant compilation and Eclipse's compilation. Make the Ant script the way you describe (i. e. compile the main and test directories separately and create two separate jar files). Change the Eclipse compile directory to something different, for instance bin/eclipse. Use the Ant script when making official builds or building for release. Use Eclipse's building only for development/debugging. This way, your two build systems will not get in each other's way and confuse each other.
Hope this answers your question and I understood it correctly. Good luck!

Writing an Eclipse-aware Ant task

I would like to write a simple Ant task that would interact with an Eclipse workspace to get some information from it. I would like to be able to use the various Eclipse API's (for example, IWorkspace).
My question is what would be the simplest way to go about doing this.
I have excellent knowledge of the Eclipse platform as a user of it - but none with development for Eclipse. I understand that, in runtime, my Ant task will have to be invoked under the same JRE as the workspace - that's a restriction I'm willing to be bound to.
I started by creating a Java project to hold my Ant task. I believe that the only thing in my way now is how to define the JAR dependency on Eclipse's JARs. I obviously don't want to depend on one specific Eclipse JAR as these are versioned (for example, Eclipse's "Resources" plugin). Is it possible to have my Java project buildtime-depend on "whatever the current JAR is for the Resources plugin"?
I think this article quite much addresses your problem: http://www.ibm.com/developerworks/rational/library/09/eclipsecustomanttasks/
It is targeted to the IBM Rational Application Developer, but that one is based on Eclipse and AFAIS there is not overly much non-eclipse-specific happening here, at least not regarding the specifics about how to make the task available in Eclipse (writing the plugin definition etc).
So, you want an Ant task that runs within Eclipse. And as you say, it's clear that those tasks are using the Eclipse API. As of this moment, I don't really understand how they're doing it. I've looked at the source of a couple of them and I still have questions.
To find the locations of all the Ant tasks contributed by Eclipse, do a Plug-in Search for org.eclipse.ant.core.antTasks. When I do that, I see twenty or so extensions, many of which define multiple tasks.
If you get the source bundle for a plugin that contributes one of these tasks, you can look at the source for it. RefreshLocalTask is in org.eclipse.core.resources; unfortunately, when I import this bundle into my workspace as a source project, the source for the Ant tasks doesn't get linked correctly. There is a separate jar (inside the bundle) for them, and, while the source is in the bundle, it's not clear how the jar is compiled. The upshot is that I don't have the Ant task source compiling in my workspace.
You can also Google for the Ant task source; here's the 3.6.0 source for RefreshLocalTask.
Anyway, in the source you can see calls to org.eclipse.core.resources.ResourcePlugin that are illustrative of what you probably need.
Ah, I see in the extension point description - right-click on one of those search results and choose "Show Description", or go there from the Manifest editor - that there is a flag you can set, "eclipseRuntime"; the text implies that if it is set, Eclipse will launch the task in the same VM.
You should probably say more about what you want to do, because there are several routes you can take.
Eclipse provides some Ant tasks that you can use in your build scripts. Here are a few. There are more, so search for "ant tasks" in the Eclipse docs; they're scattered throughout different pages. Eclipse Preferences (Window..Preferences, then select Ant/Runtime, and look at the "Contributed Entries" in the Classpath tab) shows you a list of Ant tasks that Eclipse contributes to the runtime whenever Ant is invoked from Eclipse; you can invoke any of these tasks yourself as long as you include the right jar.
It's possible to start up Eclipse from within an Ant task, because it's possible to start Eclipse from Java. You need to include the right jars and make the right calls; you also need to configure Eclipse correctly. "org.eclipse.core.runtime.adaptor.EclipseStarter" should give you some detail.
Perhaps you can use one or more of the variables Eclipse defines for use when launching Ant (or any other program). Try creating an External Tool Configuration (at the bottom of the Run menu) - select an Ant Build and try customizing it with arguments (from the Main tab) or environment variables (from the Environment) tab. Both give you access to Eclipse variables. But of course these are just values you can pass into your Ant script, not handles to anything you can invoke a method on.
What you can't do: I'm pretty sure that when Eclipse launches Ant, it is always in a separate VM, with no way to call back into Eclipse.
So perhaps you should say more about what you want to do.