Develop Reference

How to save Java Project from IntelliJ IDEA to Git repo so it will build on another PC after cloning?

I'm building a simple calculator app from a tutorial/class on Pluralsight (Java Fundamentals class), which starts with a Main.java file, and adds a class file later, MathEquation.java.
I created a Git repo to track my progress, and uploaded to Github: JavaFundamentalsClass. I used GitIgnore.IO to find a Java IntelliJ .gitignore file, and everything seemed to be working fine on the original PC I was using.
However, after switching over to a different PC, with a fresh install of IDEA, I cloned down the repo from Github, and found that the project would not build and/or run. I get this error:
"C:\Program Files\RedHat\java-1.8.0-openjdk-1.8.0.191-1\bin\java.exe" -Dfile.encoding=windows-1252 -jar ""
Error: Unable to access jarfile
Process finished with exit code 1
I suspect that there is something in the .gitigore file that is keeping some of the project, dependency, or build information from being saved in the repo that keeps IDEA from having all the info it needs to build and run the Main.java correctly.
Can anyone help? You should be able to download the project from the repo linked above in it's currently broken state, including the .gitignore file.
Additional Info
I wiped my repo clean and recloned and I forgot, originally it doesn't even give me the run button (it is grayed out). I had to do a procedure with "Add Configuration" from a search I did for that to show up to get the error above.
Also, I did install java from the OpenJDK, rather than oracle. I figured with Oracle cutting off commercial development maybe start the switch now as I'm learning, but maybe that's the issue (normal Java on my other PC).
It's working, but...
First thing - Intellij needs to know where Java is. It appears that if the SDK/JDK is not installed prior to Intellij, you will need to tell it where Java is after installing. Or if you use OpenJDK instead of Oracle Java SDK. You can do that at View/Open Library Settings, under Platform Settings / SDKs (select the JDK home path).
Then, after setting up Java, I am able to get everything working in Intellij IDEA if I find the Main.java file, right-click, and choose "Run main.main()". This runs the program okay, and also creates a Main configuration in the Run/Debug configuration area, and finally the "Run" button becomes available.
So I can get it working, but if I wipe all the files and clone it fresh from the remote repo, I have to go through running the Main.java file directly again to recreate the configuration.
So, this still doesn't answer my original question. Why doesn't this configuration get saved in the repo? What file is this information saved in? Is there something in the .gitignore file that is keeping this information from being saved to the repo?

Look like you have a different java version on your second machine.
First of all, check your java version
Update the configuration of your project, right now it pointing to java 1.8
https://github.com/LightCC/JavaFundamentalsClass/blob/master/.idea/misc.xml

I think it might be because of java not installed on the other PC you were trying. If it is installed just check whether the path mentioned has java executable file.

The first part is ensuring Java is setup, and that Intellij IDEA knows where Java is, per the other answers, comments, and addendums to the question.
The second part is setting up the run/debug configuration, per the "It's working but.." section of the question. This can be created automatically by right-clicking the file that has the main class to be run (usually Main()...), and selecting the "Run Main.main()" option (replacing Main and main() with the file and function which needs to be run)
The final piece is that to get the run/debug configurations to save to the repo, you either need to:
Share the workspace.xml file (i.e. make sure this is not in the .gitignore file). However, there is a lot of user-specific stuff in that file, so it should normally be excluded from the repo.
Or, edit the configuration and checkmark the "Share" box in the upper right-hand corner (just right of the "Name" field). This will put the configuration into a separate folder inside the .idea folder, which should not be excluded from the repo by .gitignore.

Specified VM install not found: type Standard VM, name jre7

Specified VM install not found: type Standard VM, name jre7
Have you ever encountered this problem in Eclipse while building an ant file? Then this article is for you. Deleting and recreating the workspace is not the solution. There is an easy solution to fix this issue without recreating the workspace.

Right Click on build.xml
Go to "Run As" >> "External Tools Configurations..."
It shall open new window
Go to JRE tab
Select proper JRE if missing (sometimes jre tabs shows error mark on that.)
For more technical details or issue similar to this find my blog here.

In my case it happen as I have changed my JRE.
Solution :
Right click on your ant script > Run as > External tool configurations... > Go to JRE tab > select JRE
Hope this help.
Thanks,
Sagar Vyas

Best answer found at
It happened for me after Un-installing Java and installing new version.
All I have to do is in eclipse open Installed JREs from
Windows --> Preferences --> Java --> Installed JREs
Then Add new JRE information. Details can be found here

This is a preferred way tell projects which JDK container to use, especially true if two or more devs are using the same version controlled eclipse project folder.
Window/Preferences/Java/Installed JREs
List one or more JDKs installed on your computer. Eclipse defaults name to jdk1.X.X_XX you should keep it as is. Never link project build settings directly to use these names.
Window/Preferences/Java/Installed JREs/Execution Environments
List of common jvm environments such as JavaSE-1.6 and JavaSE-1-7 names. Click rows and choose jre instance on the right side panel. These names are common and all team members should already have them in Eclipse installation.
Step 1: This is where you may accidentally have nothing chosen if JREs were uninstalled or names changed in InstalledJREs setting. You may get
Specified vm install not found error dialog.
Step 2: Choose 2nd mouse on build.xml file/Run As/Ant Build... popup menu entry. Click on JRE tab and choose execution environment. This may have obsolete value from the previous jdk values.
Project Properties/Java Build Path/Libraries
Add Library.../JRE System Library/(x)Execution environment
Choose execution environment to be used for this project. Team members may not have exact _XX jdk build but they can use the same version controlled eclipse project settings. Execution environment mapping hides user specific details.

Just had this issue & the solution above does not work, atleast not for me.
Instead I went the solution provided here:http://www.javaworkspace.com/VMNotFound.do
Essentially you go to the directory C:\projects\WORKSPACE.metadata.plugins\org.eclipse.debug.core.launches
In there search for the string of the JDK that that eclipse is moaining about & change it to the name of your installed JDK that you want to use that eclipse knows about.

You can change what JRE the ant bulid file is launched with inside eclipse.
Right click on the ant file in the ant view and select "Run As"->"Ant..." from the context menu.
Then in the launch dialog select the JRE tab. Note the error message at the top if it can't find the JRE that it expects.
Select a JRE that you have installed or manage install a new one. You can also add vm arguments (enable logging or change memory alocation) if you need to in this dialog.

Just delete the below file
"<Your eclipse workspace location>\.metadata\.plugins\org.eclipse.debug.core\.launches\<projectname>.xml.launch"
link to post

The last answer is absolutely correct, however a fast track way is to delete the project reference from eclipse (make sure to keep unchecked delete source) and import your project folder again. This way the project configurations are reset by eclipse using the new jdk.
But a wonderful post it did help me.

After Java update ant build failed and the below steps fixed it .
Right Click on build.xml-Run As-External Tools
Go to JRE tab and check the box to use the JRE same as workspace.

Removed below file and build maven project again, worked for me.
.metadata.plugins\org.eclipse.debug.core.launches\.xml.launch"

(ant file)Run As--> External Tool Configuations,
go to JRE tab and choose JRE

RCP's exec launcher can't find companion shared library on launch, but starts with click on org.eclipse.equinox.launcher_1.2.0.v20110502.jar

I'm building an Eclipse RCP application against Eclipse 3.7.1 and Java 1.6.
I'm also using Tycho to build, and have set up my RCP according to the Tycho tutorial from the EclipseCon 2011, to which I've stuck slavishly, apart from project names.
The application builds fine up until I get to Step 5 (adding a p2 repo, then adding a .product file. Well, it still builds fine, and everything is where it should be, but I cannot start the RCP by clicking on the .exe file from the repository in the workspace.
All I get is the old dreaded "The [RCP] executable launcher was unable to locate its companion shared library" error popup.
First of all I thought I might have set up the CLASS PATH incorrectly, but when I open a console and type javaw or java -version anywhere, it all works.
Also, when I go to the pluginsfolder in the p2 repository for the RCP in the workspace, and double-click on org.eclipse.equinox.launcher_1.2.0.v20110502.jar, the RCP starts, albeit without the splash screen.
This must surely mean my Java set up is correct, and it's not a class path problem?
I'm not sure where this problem might lie (I have a plugin, a feature, a product, a repository, and a parent package with the main pom), so if you let me know your suspicions where the error might come from, I'll be more than happy to post respective XML, build.properties, screenshots and what have you. Unless this is a common error with a common solution.
Many thanks in advance!
Oh yea: Windows 7 (64-bit), JDK and JRE both 64-bit as well, Eclipse EE 3.7.1 (I chose that because it contains the most plugins I'll need later by default).
UPDATE
I'm attaching my CLASS PATH Settings for reference.
User variables
CLASS PATH: C:\Program Files\Java\jdk1.6.0_30;.;
System variables
JAVA_HOME: C:\Program Files\Java\jdk1.6.0_30
Path: %JAVA_HOME%\bin;
UPDATE 2
When I let Tycho create a ZIP file in the p2 repository, and copy that from the repo to another location, unzip it and run the .exe, the application starts without problems. So I guess this query is partially solved, but I'd still be interested to hear why I wouldn't be able to start the application from the repository...

Today I came across the same issue. I guess you could find the solution here: https://bugs.eclipse.org/bugs/show_bug.cgi?id=176084
In short, the problem in my case was, that the org.eclipse.equinox.launcher_1.2.0.v20110502.jar must be unpacked in the plugins folder under the folder name: org.eclipse.equinox.launcher_1.2.0.v20110502
... hope that helps!

In my case the error The [RCP] executable launcher was unable to locate its companion shared library was because my path was too long.

Same issue I was facing from yesterday. Today, I have changed path of project(git clone) and build it and able to run RCP executable.
I think this issue was because of path too long.

Eclipse Can't find default Java Classes on Mac OS X

I have done Android and C development in my copy of Eclipse, but have never actually done Java strictly. When I add code that compiles using "javac codename.java" to an eclipse project, eclipse gives me errors and can't recognize statements like import java.io.* . I believe this is due to a problem with my class path and I have tried adding some paths like library/system/java but have not had any success. Any ideas for a solution?

If Eclipse is having troubles with classes delivered by JDK, I would suggest checking out if it (thus - JDK) is properly installed. You may do that by going to menu Window > Preferences and started typing "jdk" in search input. It should point You to Java > Installed JREs. Check if there is proper JDK installed (if not - You may add it there).
After that try to clean Your project - menu Project > Clean....
Hope this helps, regards.

If you go into the preferences dialog and go to Java/Installed JREs, make sure those paths are correct.

In order for Eclipse to recognize source files as Java and compile them, your project has to be a Java project. Putting a .java file in a project that wasn't created via New / Java Project won't work.
Please try creating a Java project and put your .java file in it.

On os x the default location (right now anyway) is /System/Library/Java/JavaVirtualMachines/[VERSION].jdk/Contents/Home
The default location is available from /usr/libexec/java_home.
That said, I've never had any problems with eclipse not finding the jdk, usually it's all
automatic.

Getting a lightweight installation of Java Eclipse

Having dealt with yet another stupid eclipse problem, I want to try to get the lightest, most minimal Eclipse installation as possible.
To be clear, I use eclipse for two things:
Editing Java
Debugging Java
Everything else I do through Emacs/Zsh (editing JSP/XML/JS, file management, SVN check-in, etc). I have not found any aspect of working in Eclipse to do these tasks to be efficient or even reliable, so I do not want plug-ins that relate to it.
From the eclipse.org site, this is the lightest install of eclipse that they have, and I don't want any of those things (Bugzilla, Mylyn, CVS xml_ui), and have actually had problems with each of them even though I do not use them.
So what is the minimal build I can get that will:
Ignore SVN metadata
Includes the full-featured editor (intellisense and type-finding)
Includes the full-featured debugger (standard Eclipse/JDK)
Does not have any extra plug-ins, platforms, or "integrations" with other platforms, specifically, I don't want to deal with plug-ins relating to:
Maven, JSP Validation, Javascript editing or validation, CVS or SVN, Mylyn, Spring or Hibernate "natures", app servers like a bundled Tomcat/GlassFish/etc, J2EE tools, or anything of the like.
I do primarily Spring/Hibernate/web-mvc apps, and have never dealt with an Eclipse plug-in that handles any of it gracefully, I can work effectively with my own toolset, but Eclipse extensions do nothing but get in the way.
I have worked with plain eclipse up to Ganymede, MyEclipse (up to 7.5), and the latest version of Spring-SourceTools, and find that they are all saddled with buggy useless plug-ins (though the combination is always different).
Switching to NetBeans/Intellij is not an option, and my teammates work with SVN-controlled .class/.project files, so it pretty much has to be Eclipse.
Does anyone have any good advice on how I can save a few grey hairs?

You can download the empty Eclipse platform and then manually install the JDT tools.
Go to the The Eclipse Project Downloads page.
Choose the bundle you want, probably Latest Release.
On the download page of the chosen bundle:
Download Platform Runtime Binary
Download JDT Runtime Binary
Extract the Platform Runtime Binary archive file and run it (for example, by double clicking on eclipse.exe).
Install the JDT binary:
Click Help → Install New Software → Add... → Archive.
Choose the JDT zip file you downloaded.
Uncheck Group Items by category.
Select the Eclipse Java Development Tools.
Click next to install and restart Eclipse when prompted.
JDT from the Eclipse update site
You can also install JDT from the Eclipse update site, instead of downloading the binary.
To do this, do this following:
Skip downloading the JDT Runtime Binary, only download, extract and run the Platform Runtime Binary.
Go to the Install New Software, but instead of Archive chose the Eclipse download site.
Search and install Eclipse Java Development Tools.

The "Eclipse IDE for Java Developers" version isn't the smallest one! Look for "Eclipse Classic" - it doesn't contain most of the things you mentioned. It's larger in download size only, because it comes with source code.
See this comparison: http://www.eclipse.org/downloads/compare.php

You can use a thirdparty distribution builder like Yoxos and download just what you want.

A bit late to this party, but I asked myself the same question for a while, and while now I'm back to a more fully-fledged Eclipse installation, I used to to the following to streamline it a bit. Hope it helps.
What I Needed
Functionalities:
Java Support
Java + Java EE (XML) + Debug Perspectives
Pretty much it. There's a lot of other things I like to use in Eclipse, but I needed to keep it down to the skinniest possible because I was in a 3GB environment where I also needed to run other servers in parallel, so I couldn't afford much.
Resulting Perspectives:
Lightweight Java
Lightweight Browser (fairly tweaked for code reviews and code inspection - that one was actually heavier than the others)
Lightweight Debug
What I Did
Install Eclipse Java EE (install classic if not caring about the Java EE/XML bits)
disable hungry views
disable outline (when you need one, just do CTRL+O)
disable call and type hierarchies
disable decorators
disable menu entries (right-
disable toolbar items
even better: hide the toolbar
disable hovers and actions associated with that
disable spell-checking
disable XML validation
disable Mylyn
disable non-needed search forms in CTRL+H dialog (I usually actually only use the "File Search" mode, sometimes the "Java" one)
disable usage reporting
disable unnecessary plugins or features
disables perspectives and plugins loaded automatically on startup
restrict internal limits:
some views have a scope (enclosing class, project, working set, workspace...)
some views and UI elements have boundaries (console/loggers, highlighters, markers...)
tweak the eclipse.ini to:
-clean the workspace (slower, but I tend to prefer to do that)
use G1GC
reduce memory usage (I noticed that I can perfectly live with -xss128k and -xmx384 with G1, for instance. YMMV, of course, as always with JVM tuning.)
use a server VM (and point directly to the VM's DLL)
Also disable views you don't need in the "Debug" and "Code Browsing" perspectives.
Sorry, I had actually saved all of these as a set of 3 lightweight perspectives to re-import everytime on my new project, but I cannot get my hands on them at the moment. If I ever find then, I'll add a link to them here.

Instead of going for a ready package from Eclipse Downloads, from the same page go for the Eclipse Installer. Currently available for Mac, Windows & the beloved Linux. Launch the Installer which should update (or not if you are lucky enough :) ). Select "Eclipse Platform" which is the absolute minimum from this IDE, set your other installation preferences and install.
After the download/installation process, I'd suggest your head to Help->Install New Software and search for the Eclipse Marketplace (Yes, even that is not included in this package) just to make your life a bit easier.

Get as minimal an installation as you can, and then remove whatever is left that you don't want.
Longer answer:
I played around a bit. Here's how I experimented:
Extract a clean eclipse*.zip to two different directories; call it eclipse and eclipse-bak. We'll only modify eclipse.
Before starting it the first time, remove some of the features from the features folder. I got rid of org.eclipse.cvs, org.eclipse.epp.\*, ...mylyn\*, ...wst\*.
Start up Eclipse to a workspace. Create in that workspace a Java project, debugging configuration, etc. Stuff that you would want to do and that will complain if we remove the wrong thing. Open up the Error Log view.
Close Eclipse. Remove something (or a group of things) from the plugins folder.
Open Eclipse. Check the error log to see if something you care about couldn't load. If it did, add those things back from eclipse-bak/plugins. If not, close Eclipse and return to step 4 for a new set of plugins.
Using this I got my configuration to still be able to edit and debug Java files, but including only these plugins:
com.ibm.icu*
org.apache.*
org.eclipse.compare*
org.eclipse.core*
org.eclipse.debug*
org.eclipse.draw2d*
org.eclipse.ecf*
org.eclipse.epp.package.java*
org.eclipse.equinox*
org.eclipse.help*
org.eclipse.jdt*
org.eclipse.jface*
org.eclipse.ltk*
org.eclipse.osgi*
org.eclipse.platform*
org.eclipse.rcp*
org.eclipse.search*
org.eclipse.team.core
org.eclipse.team.ui
org.eclipse.text
org.eclipse.ui*
org.eclipse.update*
org.hamcrest*
org.sat4j*
Most of that is core stuff, but you might be able to trim it down further. Notably gone are Mylyn, the usage collector, EMF, CVS, WST, even JUnit (though I think you should keep JUnit).

I feel you man, when working with Eclipse, the application is constantly trying to help.
Ignoring workspace corruptions, I spend my development time fighting all the "helpful" things Eclipse does.
XML is not that hard to read, but it still confuses the shit out of me when I get the XML designer.
All it does for me is add an extra manual step to click on the source tab.
Every time a new version of eclipse comes out they redesign the front page and the distributions.
At which time a new quest starts for finding a way to debloat Eclipse again.
I have the same experience with extensions to Eclipse by third parties and avoid them if at all possible.
WTP has somewhat usefull stuff, but overall I prefer a basic java eclipse.
It is a good idea start with the Platform Runtime Binary and add JDT.
Manually extracting the JDT runtime doesn't seem to work for me these days, so it it better to use the update client.
You can use the marketplace client, but personally I have always found it rather annoying.
An alternative is to use the director. The director can install JDT without starting the GUI.
Here is a script that downloads eclipse Oxygen 4.7.3a and installs JDT unnattended:
#!/bin/sh
die() {
echo >&2 "$#"
exit 1
}
[ "$#" -eq 1 ] || die "exactly 1 argument required [INSTALL_DIR]"
[ -e "$1" ] && die "*warning* Aborting! location exists, eclipse already installed?"
INSTALL_DIR="$1"
TARBALL=eclipse-platform-4.7.3a-linux-gtk-x86_64.tar.gz
mkdir -p $INSTALL_DIR
if [ ! -f $TARBALL ]
then
wget http://mirror.csclub.uwaterloo.ca/eclipse/eclipse/downloads/drops4/R-4.7.3a-201803300640/$TARBALL
fi
tar -v -xf "$TARBALL" -C "$INSTALL_DIR" --strip 1
echo "\nUsing director to install java development tools, this may take a while..."
$INSTALL_DIR/eclipse -noSplash -application org.eclipse.equinox.p2.director -repository http://download.eclipse.org/eclipse/updates/4.7 -installIUs org.eclipse.jdt.feature.group
Simply call the script with one argument, the directory you want Eclipse installed.
Running the script gives me an unpacked install of roughly 129MB, which is more than 100MB smaller than the default download (zipped).
That is not to say you would not be able to shrink it further, but it should rid you of most of the crap.
The executable will be cached for future executions of the script, but it will still be slow, since it needs to go online to download JDT.
Unfortunately, I do not know of a way to cache the plugin download in a local folder.
You could of course zip the created installation, but the script is easier to commit to git.
This script will only work for new users as long as the mirror stays up and will need some updates when a new version is released.
But I am sure most developers are savvy enough to update the script if need be.

If you only want to use Eclipse for editing / Debugging Java I would suggest using a plain Text editor. It seems an overkill to install Eclipse and not use most of its features.
A very popular choice is VIM. Also check out this SO link for tips in using VIM as a Java editor. You can also debug Java code with a command line debugger as mentioned in this SO link.

I have figured out how to get the lightest possible eclipse with minimal efforts(imo). For the reference this is what I want in my eclipse:
Java project with Maven support
JavaEE support(Servers)
Debugging of Java application
(Irrespective of these you can install any feature that comes with Eclipse IDE with minimal effort, just follow the guide below)
Here's how I get it:
Go to eclipse download packages (Here's the link)
Find MORE DOWNLOADS (right hand side) and go to Other builds (Here's the link)
Now go to any build you like (Usually Latest Downloads -> whatever the first Build Name. Also There is links for older versions and archive site)
Under Platform Runtime Binary you can download Eclipse Platform as per your OS and/or requirement.
Now extract the archive and run the eclipse
Go to Help -> Install New Software...
Using Work with you can install your desired plugins and tools which usually ships with bulky eclipse
In Work with drop down select the site(mostly first) similar like this 2022-03 - https://download.eclipse.org/releases/2022-03 here 2022-03 is my eclipse version you may see different depending your version.
Now you can select the group(s) or expand the group(s) and select the specific plugins which you need and also you can filter by name like maven, debug, server, marketplace client etc in filter text input just below the Work with drop-down menu.
Install plugins and enjoy your very own lightweight eclipse.

Visual Studio Code
Fast forward to 2019 and we now can use Visual Studio Code with Java plugins. They provide a plugin pack to get you started with lightweight debugger and auto complete. Other plugins include maven integration, dependency viewer and more.
Visual Studio Code is a new(ish) editor/mini-ide from Microsoft which runs on Win/Max/Linux and has plugins for many languages.
Tutorial for setup: https://blog.usejournal.com/visual-studio-code-for-java-the-ultimate-guide-2019-8de7d2b59902
Edit 2019-06-21: MS now has a dedicated installer for Java integration with VS Code, including Spring Boot support as well. While the Intelisense is not 100%, it's vastly improved and now my go-to Java editor for testing and trying new things. Announcing the Visual Studio Code Installer for Java