Is it possible to modify eclipse workspace via command-line? - java

Is it possible to access/manipulate an eclipse workspace via command-line?
I'm primarily asking about the workspace metadata rather than the files itself.
E.g. do things like
modify resource attributes (e.g. settings some resources to derived)
import existing projects
access markers

There are no command-line (headless) tools that I know of to perform these types of tasks. There are a few scripting projects for Eclipse out there that would provide a light-weight, scriptable interface to using the Eclipse API, however, none of them have command line available, I believe all of those scripting tools are UI based.
Another option would be to use Eclipse SDK to build an Eclipse application (headless app) that uses the Eclipse application model to perform the commands you wanted, but you would have to write the code yourself.

Here is a list of eclipse command line options: http://help.eclipse.org/indigo/index.jsp?topic=%2Forg.eclipse.platform.doc.isv%2Freference%2Fmisc%2Fruntime-options.html
Doesn't seem like there's one allowing to set the workspace, though...

Eclipse is not designed to be used on the command line. If you want to work with the command line I would highly recommend to use a build manager like Apache Maven or Apache Ivy in your project. The advantage is that your build does not depend on Eclipse, you can switch the IDE if you want and you can build your projects and edit dependencies on the command line. Your project and its build/deployment should be independent of an specific IDE.

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Right way of working Java Eclipse project with GIT

What's the right way of working with an Eclipse Java project with GIT?
I have the plugin EGIT installed and a simple java project. I did a commit/push of this java project by using the GIT bash console. I pushed only the source files.
Is that correct? Should I use Eclipse IDE somehow to make the init, commit and push? I couldn't find how to do this in Eclipse.
How should I retrieve the project from another machine? Should I use GIT console to retrieve the project or Eclipse?
I did the procedure in several ways, but they failed.
The generic answer is: whatever works for you, works.
We have a large git repository, and users with eclipse and intellij.
Some IDE users use specific plugins, such as Egit, others simply use the "default" support that most IDEs are shipped with. Such users simply go command line, or maybe, some other 3rd party tool.
Me, personally, I only rely on the IDE to show me the history of a file, or sometimes to quickly diff to revisions. Anything else I do on the command line.
From that point of view, as said: anything that works for you, works for you. You can use eclipse to manage the aspects of a git repository, but you don't have to.
Personally, I suggest to first get a good book on git, and to then extensively study the command line tooling. You also seem to be confused between the responsibilities of your IDE, and your source code management system.

Local Java package management system in Python PIP style?

I want to program in Java or other JVM languages like Scala, Kotlin, or Groovy. When I am programming on my projects, I only want to have import statements in my Java/Scala/Kotlin source files without the need to state the packages a second time in a Gradle/Maven build script. Instead I want to work as I would do in Python, i.e. have my import statements at the beginning of my source files and I am done.
The packages should then automatically included when I am compiling if all packages are installed in a central local package management system or otherwise get an error message telling me that I have to install a missing package. It should essentially work the same as for Python and PIP respectively.
Is a workflow like this possible preferably with Groovy or Maven?
Thanks in advance!
The closest I can think is Grape:
Grape is a JAR dependency manager embedded into Groovy. Grape lets you quickly add maven repository dependencies to your classpath, making scripting even easier. The simplest use is as simple as adding an annotation to your script:
#Grab(group='org.springframework', module='spring-orm', version='3.2.5.RELEASE')
import org.springframework.jdbc.core.JdbcTemplate
Like in this example:
#Grab('net.sourceforge.nekohtml:nekohtml:1.9.16')
def parser = new org.cyberneko.html.parsers.SAXParser()
def page = new XmlParser(parser).parse('https://news.google.com/nwshp?hl=zh-TW&tab=wn')
page.depthFirst().DIV.grep{ it.'#class'=='title' }.each {
println it.A.SPAN.text()
}
I can't judge the Groovy landscape since I don't have any experience there, but for developing Java or Scala applications this exact workflow is not possible as far as I know.
Regarding "I only want to have import statements..." I think the closest you can get is good Maven/Gradle/sbt integration in an IDE, like IntelliJ that automatically adds the desired library to your build system's configuration file when using the correct shortcut. It (at least) works for some Java libraries when you're dealing with a Maven project in IntelliJ.
And regarding your other wish to have packages automatically included when compiling: On the JVM there is the concept of the fat JAR (also called uber JAR), which is basically a JAR (Java archive) that contains all dependencies and is thus self-contained. Usually you can start the application contained in it with a single java command.
To build fat JARs you need to have the approriate plugin for your build system:
For Maven that would be the maven shade plugin, see https://maven.apache.org/plugins/maven-shade-plugin/
For sbt you can use the assembly plugin, see https://github.com/sbt/sbt-assembly
Gradle probably has something similar
A lot of Java frameworks also come with their own build plugins that make building such self-contained applications relatively simple (Spring Boot is one example, but only suitable for applications that on top of an HTTP server)
Hope this helps, althought it's not an accurate answer to your question. :)

Is it possible to load an eclipse Java project using JDT in the headless mode?

I have an eclipse Java project and want to get information like project source dir, classpaths, etc. My current implementation parses the .project file. But as I didn't find any official documentation describing the structure of the .project file, I have some concerns for the robustness of this approach.
A more convenient and robust way would be to use JDT (headlessly) to load the project and get the relevant information from the IJavaProject object.
Although the developer guide of JDT says
JDT Core packages give you access to the Java model objects and headless Java IDE infrastructure.
all the examples I can find opening an existing Java project get the IJavaProject object from projects within a workspace or use an IProject object. But I couldn't find the way to add a project to the workspace or to construct a IProject/IJavaProject from a path to .project file.
Could anyone please help?
Yes, and can all be done through clear and stable API. org.eclipse.jdt.core is a plug-in, just like org.eclipse.core.resources (which is where you would get an IWorkspace instance), and they both expect to be running within an Eclipse runtime, which can be headless if that's how you write your Eclipse Application. JDT uses the .classpath file to record where sources, libraries, and build output are, and what abstracted references to libraries to use, while the .project file is what records what kind of project it is in general--Java, PHP, Web, some combination of those or others--and a little more information about what builders to execute.
So make yourself a headless Eclipse Application, or package your end-goal functionality inside of one.
https://wiki.eclipse.org/FAQ_What_is_an_Eclipse_application%3F
https://wiki.eclipse.org/FAQ_What_are_extensions_and_extension_points%3F
http://help.eclipse.org/mars/topic/org.eclipse.platform.doc.isv/reference/extension-points/org_eclipse_core_runtime_applications.html?cp=2_1_1_27
http://help.eclipse.org/mars/topic/org.eclipse.platform.doc.isv/reference/api/org/eclipse/core/resources/ResourcesPlugin.html#getWorkspace--
http://help.eclipse.org/mars/topic/org.eclipse.jdt.doc.isv/reference/api/org/eclipse/jdt/core/JavaCore.html#getJavaCore--
http://help.eclipse.org/mars/topic/org.eclipse.jdt.doc.isv/reference/api/org/eclipse/jdt/core/IJavaProject.html#getResolvedClasspath-boolean-
See http://www.ant4eclipse.org/ for a project which allows you to work inside Eclipse projects.
I used it for a bit some years back, and found that this is too brittle for long term usage and build scripts. I would recommend against relying on internal Eclipse things. They break! Typically when mixing releases.
Instead I would suggest you move to Maven. This is a bit more work, but allows you to use the whole maven infrastructure and API's to do things. What you want to achieve here, may be possible already using a Maven plugin.

How can we automatically disable an Eclipse plug-in on target platforms?

We have developed an Eclipse plug-in called CodingSpectator that collects some data about the usage of various Java development tools in Eclipse. This data helps us better understand how developers use Eclipse and how we can improve Eclipse to better suit the needs of programmers. CodingSpectator captures data from every workspace that is opened in Eclipse. Some of our users develop RCP applications or Eclipse plug-ins. Therefore, they run new instances of Eclipse from their main instance of Eclipse. However, we don't want CodingSpectator to collect data from the target platforms (new instances of Eclipse opened from within the main Eclipse). So, we instruct our users to configure their target platform to exclude CodingSpectator (See http://codingspectator.cs.illinois.edu/resources/documentation/user-guide.html#htoc6). But, configuring the target platform manually is not convenient. And, we are looking for better ways to stop capturing data from target platforms.
How can we automatically disable CodingSpectator on the target platforms of our users?
One way could be to look for the -dev application argument. This argument is always added by PDE when launching an application from within Eclipse.
I used Platform.inDevelopmentMode() to determine if the instance Eclipse is run from within another instance of Eclipse.
For at least RCP applications, it's likely that a target has already been defined, for stability across a team and a release.
But for those cases where someone wants to test a plug-in using the developer's version of Eclipse, perhaps you could provide a utility to make the target.
A target can be defined by a file in a project. You could provide a utility that generates the file. All the user would have to do would be:
Run your utility
Refresh the project (if necessary).
Open the generated target file in the Target Editor.
[OPTIONAL] Modify the generated target further.
Click on the "Set as Target Platform" link in the upper-left of the Target Editor.

How to see full compile path in Eclipse?

I have looked for an answer for this nearly every where that I can think of, but there doesn't seem to be any way to actually SEE what Eclipse "runs" to compile the projects (as it does need the JDK installed and visible to actually build). I ask because I imported a few jars into my project, and even though I've looked through all the javac documentation, I can't seem to figure out how to mimic it quite like Eclipse does. I really, really need to be able to compile on the command line in this case - Eclipse or any other IDE just isn't what is needed.
I started to look through the Eclipse source, and although this sounds lazy, I just became overwhelmed and figured I would ask here first, hoping someone else had the same question at one point.
Eclipse JDT does not require the JDK and does not use javac - it uses it's own compiler.
You can see the classpath by reading your project .classpath file. The various builders that are used to perform build operations (Java, or whatever the project builds) are listed in the .project file. (These are also listed in the project settings.)
It is possible to invoke Eclipse to build your project in headless mode, or write Ant scripts that can be executed both with the JDK and within Eclipse, or install Maven support for internal and external building. It is also possible to configure the project builders to rely only on external tools.
Look at these two articles.
http://www.eclipse.org/articles/Article-Builders/builders.html
http://www.eclipsepluginsite.com/builders-natures-markers.html
Look at your .classpath file and start building an ANT build.xml. You need to do this to be able to have consistent builds on a build machine anyways. It is unlikely that a build server would have eclipse installed on it anyways.
Maven is also another tool that is used for builds. In our shop we use Ant.
Have a look at ant4eclipse - this project allows for generating the appropriate ant data structures for invoking <javac> from the .classpath files and a projectSet.psf file.
By using this we can use Eclipse "natively" and bend ant to conform to Eclipse. The usual approach is the other way around.

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