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Revision as of 23:28, 13 May 2009 by (Talk | contribs) (What is the Update Manager?)

A collection of FAQs gathered in the Eclipse IRC channels. Some of them are logged, see the specific channel for details.



What are #eclipse and #eclipse-dev about?

  • #eclipse is about development with Eclipse (for development of Eclipse, please see #eclipse-dev). log
  • #eclipse-dev is about development of Eclipse (for development with Eclipse, please see #eclipse).

I am looking for help with developing with Eclipse. Should I ask on #eclipse or #eclipse-dev?

Probably #eclipse as long as your question relates to Eclipse usage or plug-in/RCP development. If the issue is purely a language issue unrelated to Eclipse, you should find a more appropriate channel that deals with that programming language. For example, freenode has a ##java channel for Java-related questions. You will need to be registered to nickserv to enter that channel though.

Are there other active channels about Eclipse?

Yes, there are several other channels that are specific to projects hosted at

Others are listed below:

  • #eclipse-e4 is the E4 discussion channel - log
  • #azureus about Azureus, an Eclipse-based BitTorrent client
  • #easyeclipse about EasyEclipse, an Eclipse distribution
  • #phpeclipse about PHPEclipse, an Eclipse-based IDE for PHP
  • #rssowl about RSSOwl, a RSS reader built on Eclipse RCP
  • #subclipse about Subclipse, a Subversion plug-in
  • #udig about UDIG, an Eclipse-based GIS toolkit
  • #weblogic-eclipse about the Webglogic plug-in
  • #higgins about the Higgins Eclipse project

If you are using Linux, please consider visiting #fedora-java, #gentoo-java, and #ubuntu-java for distribution-specific questions.

Nobody is answering my question. What should I do?

First, be patient, the person that has an answer for you may be busy at the moment. Then please continue being patient as that person may be in another time zone. Be polite and gentle or you may be politely ignored. If nobody answers, it may just be that nobody knows the answer. You will have to do some research on your own. The Eclipse newsgroups are a good place, as well as Eclipse's Bugzilla system. Remember that search engines are your best friends, and good luck! For those that have some idea of a possible solution, please do not hesitate to speak up!

Note also that not every project has experts or users who idle on IRC. So, here's a few other ways to get help:

  1. Read the FAQs: Eclipse FAQs, Graphical Eclipse FAQs (these FAQs have screenshots accompanying you to guide you to the possible solution), More FAQs
  2. Learn about the tools/projects you use from their websites or wiki pages
  3. Ask a question on the newsgroups
  4. Submit a question / discuss an issue / keep up to date in the mailing lists
  5. Browse source code in CVS to find an existing solution
  6. Read the online ISV help docs and APIs at
  7. Read articles, blogs, and other resources
  8. Watch videos of demos, walkthrus, and howtos
  9. Find, report, patch, triage, fix, or verify a bug or feature request
  10. Search with Eclipse or Google
  11. Seek legal advice about 3rd party code and IP

Installation, Startup and Runtime

I'm new, what should I read first?

Where can I get Eclipse?

What's the difference between all the different packages like 'Eclipse IDE for Java Developers' and the 'Eclipse IDE for Java EE Developers'? What do they contain? Do they contain source code?

See here.

What is Ganymede, and where can I get it?

Ganymede is the 2008 simultaneous release of 22 major Eclipse projects, including Eclipse 3.4. For a list of those projects, what they consist of, and an overview of some of these projects, see:

What is Europa, and where can I get it?

Europa is the 2007 simultaneous release of 21 major Eclipse projects, including Eclipse 3.3. For a list of those projects, what they consist of, and how to easily get them, see:

What is Callisto, and where can I get it?

Callisto is the 2006 simultaneous release of 10 major Eclipse projects, including Eclipse 3.2.

Where can I get a list of all the Eclipse projects?

Well, for starters, there's:

Where can I get project XYZ?

You can search for downloads by project or by topic.

Or, start with that project's homepage ( and look for download or update links. For example, EMF: website, downloads, updates.

Download the zip and unpack it into your Eclipse install folder, or use a .link file [1] [2] to locate the project in another folder.

Or, if using Update Manager, add the Update URL here, then download and install the features and plugins that way:

Help > Software Updates > Find and Install... > 
  (*) Search for new features > Next > 
  New Remote Site > (add the new site) > Finish

Is there a Visual Editor (VE) release for Eclipse 3.3 Europa / Eclipse 3.4 Ganymede?

Yes, but it's under development. See VE Development Resources for an install guide and development roadmap.

Is there a PHP editor for Eclipse 3.3 Europa / Eclipse 3.4 Ganymede?

Yes, there are two. Note that installing both concurrently can be a bad thing.

What is p2?

p2 is a provisioning system, under the Equinox project, that was introduced in Eclipse 3.4 and is intended to replace the former Update Manager.

What is the Update Manager?

Note: The Update Manager is now deprecated in favour of the p2 provisioning system as of the Eclipse 3.4 release.

How do I start Eclipse?

The simplest way:

  • Double-click eclipse.exe or eclipse
  • Browse to the directory where you unpacked Eclipse, then run eclipse or ./eclipse

The usual way:

/path/to/eclipse/eclipse -data /path/to/workspace -vm /path/to/jvm/bin/java -vmargs -Xms256M -Xmx512M -XX:PermSize=64M -XX:MaxPermSize=128M 
- or -
c:\path\to\eclipse\eclipse.exe -data c:\path\to\workspace -vm c:\path\to\jvm\bin\java.exe -vmargs -Xms256M -Xmx512M -XX:PermSize=64M -XX:MaxPermSize=128M 

Using eclipse.ini:

Other ways:

Advanced ways:

How do I debug Eclipse? How can I see what plugins are being started? How do I start the OSGi console?

Having problems starting Eclipse or getting certain plugins to load? There are a few flags you can pass to Eclipse on the commandline or in your eclipse.ini file that might help:

  • -consolelog - log everything in workspace/.metadata/.log to the console where you launched Eclipse as well
  • -debug - more verbose console output
  • -console - start the Equinox OSGi console to interact with OSGi directly
  • -noexit - when Eclipse closes, keep the OSGi console running until you type 'exit' or hit CTRL-C so you can keep debugging

How do I find out which Java runtime environment is being used to run my Eclipse?

See here.

Can I upgrade from Eclipse 3.2 (Callisto) to Eclipse 3.3 (Europa)?

Yes and no.

It depends on what plugins you use and if they have been updated to work with the new version of the platform. If you used projects that were part of Callisto and which are now part of Europa, the answer is most likely yes. Some plugins will work on Eclipse 3.0 - 3.3 without any problems. Others are version-specific because they exploit aspects of Eclipse that were added or changed along the way (such as internal APIs not intended to be extended).

To upgrade, download a copy of Eclipse or a Europa bundle (see above). Extract the downloaded archive into its own directory (do not extract it into an existing eclipse directory), start up the new Eclipse and point it at your old workspace. If you see a message like 'cannot restore perspective' then something that your old workspace relied on (eg., some view contributed by some plugin) is not working anymore, and you'll have to search for an updated version from that plugin's provider.

If you installed features/plugins outside your Eclipse folder, you can reuse them via Help > Software Updates > Manage Configuration > Add an Extension Location to point your new Eclipse at those old plugins. However, those plugin folders must have an .eclipseextension file in them for Eclipse to accept them, and as noted above, they may not work without being updated. Details on using .link files and Extension Locations here and here.

If you use JRE/JDK1.4 with Eclipse 3.2, you may need to update to JRE/JDK5.0 as some Europa components require JDK5.0 (eg., WTP, TPTP, EMF).

Can I use my Eclipse 3.2 workspace with Eclipse 3.3?

Yes and no.

Your project files are compatible, but some of your settings may not be. You might want to export your settings from the old workspace before attempting to open it with the new Eclipse, then import them into the new Eclipse. For example, Window > Preferences... > Java > Code Style > Formatter > Edit > Export.

You might also want to start a completely new workspace and use File > Import > Existing Projects into Workspace to migrate the old projects into the new workspace. They can be copied or simply linked (referenced) in their old workspace location.

How do I use a different workspace?

Three ways:

  1. In Eclipse, select File > Switch Workspace
  2. In Eclipse, select Window > Preferences... > General > Startup and Shutdown > [x] Prompt for workspace on startup, then restart Eclipse.
  3. Via commandline, run ./eclipse -data /path/to/new/workspace/folder

What other command line arguments are available?

How do I install Eclipse on Linux?

There are many schools of thought here, depending on your comfort level with Linux and the number of users on your system.

The simplest approach is to grab the latest bundle for your distro, using something like apt-get or yum. Please note that these bundles are often not the latest and greatest because they are released in concert with the distro release cycles, not that of Eclipse. For more on these repository packages, see Linux Distributions Project, or hang out in #eclipse-linux on freenode. If you're installing on ubuntu, here's a couple walkthroughs: Eclipse 3.4 on Ubuntu, Eclipse 3.2 + WTP on ubuntu, including desktop icon.

If you want the latest, grab a Ganymede bundle or archive for your distribution. If you're on a 64-bit system and are using a 64-bit JRE, make sure you get the 64-bit version.

Save the archive into your home directory, ~ or /home/$USER/. Open a console or terminal, and type:

cd ~; tar xvzf eclipse*.tar.gz; 

To start up Eclipse, type:

cd ~/eclipse; ./eclipse -vm /path/to/bin/java

If you want to create a desktop or launcher shortcut, see this ubuntu walkthrough.

You can also install Eclipse in another location -- it's up to you, your distro's conventions, or your own preferences.

For a multi-user system, consider these three approaches or the official approach.

Once you have Eclipse installed, you can add other projects to it.

How do I install Eclipse on Solaris?

I just unzipped Eclipse, but it does not start. Why?

Here are ten possible reasons.

I just installed Eclipse on Linux, but it does not start. What is the problem?

Quite often, Eclipse will not work properly with non-Sun or non-IBM JVMs. These issues are usually related to Blackdown or GCJ. Eclipse has a list of reference platforms that it is tested against which you should try to match against. Try installing one from Sun, IBM, or BEA (eg., Sun JDK 5.0, IBM JDK 5.0, or BEA JRockit 5.0). Version 6 of OpenJDK works too, particularly with Fedora Eclipse.

Make sure that your selected JDK is the one being used when starting Eclipse by passing in the -vm flag.

eclipse -vm /full/path/to/java/bin/java

It is usually desirable to place this option in your eclipse.ini file so you don't have to type it every time you start Eclipse. If you do append it onto your eclipse.ini file, you should make sure that it appears before the -vmargs line, if you have one. Also note that -vm and the /full/path/to/java/bin/java are on separate lines.

The argument must point to the java or javaw executable, not some wrapper script like run-java-tool, as used by the Gentoo Linux distribution.

Please note that if you are on a 64-bit system and have a 64-bit JRE installed, you will need to use a 64-bit Eclipse build. If you wish to use a 32-bit Eclipse build, please use a 32-bit JRE. Mismatches will cause Eclipse to not start properly. Please see bug 221969 if you are interested in this mismatch problem.

First time downloading/installing Java for Linux? Read this or this.

Note also that there are differences between ext2/ext3 filesystems and fat32 ones. Eclipse includes a lot of long file paths, .dotfiles, and case sensitive files. If you plan to use Eclipse on linux, unpacking it onto an ext2 or ext3 filesystem is recommended.

I just installed Eclipse on my 64-bit system, but it does not start. What is the problem?

Make sure that you have downloaded the 64-bit version of Eclipse (it should have x86_64 somewhere in its name) and have installed a 64-bit JVM. Likewise, if you run a 32-bit JVM, then you should use the 32-bit version of Eclipse.

How do I install PDT?

See here.

How do I install a plug-in with multiple dependencies?

There are numerous approaches here, depending on your need and starting point.

The simplest is to grab the All-In-One bundle from the project's download site, if one is provided for your platform. Note too that if you're on a 64-bit platform and are using a 64-bit JRE, you will need a 64-bit bundle (which may not exist).

But if:

  • there's no OS-compatible All-In-One available, or
  • you already have Eclipse installed, and
  • you want to add a project to an existing Eclipse, then ...'ll need to either:

  • download the individual required projects (most download pages have a "Requirements" section you can use for reference, but this can still be a pain), or
  • use the Update Manager to install the prereqs and the project you want, too.

Note that if you're installing from multiple update sites, you have to expand each one before you hit 'Select Required' for the wizard to be able to scan those sites and resolve all your dependencies. See bug 203473.

When I try to install a plug-in, I get a "Cannot connect to keystore." error, what should I do?

Check that you are not using GCJ to run Eclipse. This problem may also surface if you are using IcedTea or an OpenJDK 6 build.

Install Java 6 from Sun and use that to run Eclipse instead.

My Eclipse just crashed, when I try to restart it, it says "workspace in use", what should I do?

There are a couple of things you can try.

  1. Delete the workspace/.metadata/.lock file.
  2. Check your running processes to make sure there aren't any remaining Java or Eclipse processes running. When in doubt, restart your computer. :)
  3. Try starting Eclipse on a different workspace (from the workspace selection dialog, or by using a command line argument like -data /home/user/tmp-workspace), then switch back to your original workspace.

Crashers, Freezing, and other Major Issues

Do you have any hs_err_pid*log files lying around? This is an error log that is generated by HotSpot, Sun's implementation of the Java Virtual Machine (assuming that is the JVM you are using). HotSpot is also the JVM being used by the OpenJDK project, HotSpot is also being used by IcedTea (which has since been renamed to OpenJDK also).

Eclipse is constantly crashing for me on Sun's Java 6 VM...

Do your VM logs point to a problematic frame at or jvm.dll? Do you see any mentions of a Current CompileTask, possibly on AbstractDataTreeNode, ParameterizedMethodBinding, CCPTemplates, or PDOMCPPLinkage? If yes, you are likely seeing a very infamous bug in Sun's Java 6 VM implementation. Try starting Eclipse with a 1.4.2 or 1.5 VM, downgrade to, or upgrade to and above. Any release between and (exclusive) are affected by this bug.

The relevant NOT_ECLIPSE bug is bug 214092 and you can read through it and its duplicates for other information. There are workarounds listed on the bug at bug 214092 comment 13, bug 214092 comment 25, and bug 214092 comment 26. Please make sure you add the arguments after the -vmargs line in the eclipse.ini file and that the entry is on its own line.

If in doubt, you should start Eclipse with a 1.4.2 or 1.5 VM from Sun, or another vendor's VM, and tell Eclipse to start use that VM to start Eclipse with the -vm argument (./eclise -vm /opt/sun-jdk-

Eclipse gets past the splash screen but then an empty window appears / Eclipse is crashing on me whenever I initiate a browser component such as hovering over Java methods for javadoc tooltips...

There are two causes to this problem. You should check your workspace's log file (located in workspace/.metadata/.log, note the period in front of the folder and file name, this is the marker for hidden files on UNIX and UNIX-based systems) if you have one. If you do, you should search for the string -2147467262, the full error will be something like org.eclipse.swt.SWTError: XPCOM error -2147467262. If you have this problem, you should refer to bug 213194. This is caused by an interface change late in Mozilla's XULRunner's release cycle. This bug will manifest if you have any lingering beta versions of Firefox 3.0/XULRunner 1.9 or Firefox 3.5/XULRunner 1.9.1. You must remove these beta versions and install Firefox 3.0 and/or XULRunner 1.9 final. Alternatively, you can simply use Firefox 2.0 and XULRunner 1.8. Eclipse should run fine on those versions of the XULRunner backend. Whatever you decide, you must remove the beta versions of Firefox and/or XULRunner in order to get Eclipse to run again.

If you did not find the XPCOM error, did you find any references to or xul.dll in those logs? Maybe you see a mention of NewLocalFile in there too? If yes, you have likely hit bug 236724. The cause of this problem is explained in bug 236724 comment 44. To workaround this problem in the 3.3.x line, you should take a look at bug 236724 comment 22. If you are comfortable using a newer build, you should try a 3.4.y maintenance build or a 3.5 build that's after 2008-07-22, these builds can be found here.

If you are seeing the problem with the empty window, that too should be resolved by installing Firefox 3.0 and/or XULRunner 1.9 final. Please refer to bug 234910 for more information.

The JEE build for Eclipse Ganymede / Eclipse 3.4 does not run for me but the Eclipse Classic build starts up just fine...

Do you see something like -vm C:\Program Files\Java\jre1.6.0_07\bin\server\jvm.dll in the error dialog? If you are using a dll or so as an argument to -vm for starting up Eclipse, there may be problems, see bug 237652 for more information. You should be able to work around this problem by using the actual java binary as an argument to -vm.

Why does Eclipse hang for an extended period of time after opening an editor in Linux/gtk+?

There seems to be a bug in gtk+ 2.10 and 2.12 that is causing certain printing backends to hang. You can try to start Eclipse with the method suggested below. This should be supported in 3.3.1 (and up) maintenance builds and 3.4 and upwards.

./eclipse -vmargs -Dorg.eclipse.swt.internal.gtk.disablePrinting

You should consider taking a look at bug 215234 for more information. You may also want to refer to bug 346903 in GNOME's bugzilla system.

Eclipse is crashing for me when performing Subversion operations on Windows. I am using Subclipse.

Have you found any JVM error logs with a mentioning of the libapr-1.dll file? If yes, you have hit a DLL incompatibility problem raised by Subversion's use of the Apache Portable Runtime library. Please see Subclipse's FAQ entry about this for more information.

I'm having memory, heap, or permgen problems, what can I do?

Eclipse is constantly crashing for me on Linux and I have a lot of plug-ins installed. There is a mentioning of "too many open files".

With around 1000 plug-ins installed on Linux, Eclipse will crash due to an excessive amount of open files. Please see bug 238015 for more information. The best workaround at the moment is to add osgi.bundlefile.limit=600 in eclipe/configuration/config.ini.


Where are Eclipse's log files located?

  • <workspace>/.metadata/.log
You can view this workspace log as a view if you have PDE installed on your computer (which you would if you have downloaded the Eclipse SDK). You can open that view via Window -> Show View -> Other -> PDE Runtime -> Error Log.
  • <eclipse install>/configuration/<sometimestamp>.log
  • <eclipse install>/configuration/org.eclipse.update/install.log

I was working on a project and doing something or other does not work. Where should I start?

  1. Try refreshing your projects.
  2. Try cleaning your your projects using the menu item Project/Clean to trigger a rebuild.
  3. Try closing/reopening your projects.
  4. Try restarting Eclipse.

Where are Eclipse preferences stored?

If you want to keep preferences from one version to the other, export them using File/Export/Preferences.

Preferences are stored in various places (this applies to Eclipse 3.1)

  • for each installation (but this may vary for multi-user installations), in files stored in <eclipse_home>/eclipse/configuration/.settings/ . There is typically one file per plugin, with a prefs extension. Note that very few plug-ins use installation-wide preferences.
  • for each workspace, in files stored in <workspace>/.metadata/.plugin/org.eclipse.core.runtime/.settings . There is typically one file per plugin, with a prefs extension.
  • for each project --for project-level settings -- in files stored in a .settings sub-directory of your project folder

Where are update site bookmarks stored?

It is within an XML file called <user_home>/.eclipse/org.eclipse.platform_3.1.2/configuration/org.eclipse.update/bookmarks.xml. Your Eclipse version may vary.

Where are my Eclipse plug-ins folder?

The plug-ins folder is <eclipse_home>/plugins. Starting with Eclipse 3.4, with the advent of p2, you should put plug-ins in the dropins/ folder.

What's the key for ...?

The three most convenient key bindings are:

  • CTRL-SPACE: Content Assist
  • CTRL-3: Quick Access -- gives you quick access to nearly everything (Eclipse 3.3+)
  • CTRL-SHIFT-L: Show common keyboard shortcuts (Eclipse 3.2+)

Here are a few others:

  • CTRL-F6 / SHIFT-CTRL-F6: Cycle editor windows forwards / backwards
  • CTRL-F7 / SHIFT-CTRL-F7: Cycle views forward / backwards
  • CTRL-F8 / SHIFT-CTRL-F8: Cycle perspectives forward / backwards
  • CTRL-E: Show editor list / select editor window
  • F5: Refresh selected folder / file (useful if you edit files outside Eclipse)
  • SHIFT-ALT-X: Run As...
  • SHIFT-ALT-D: Debug As...
  • SHIFT-ALT-Q: Open View...

You can also remap key bindings via Window > Preferences... > General > Keys to suit your personal preference.

How do I add my own bindings?

See Platform Plug-in Developer Guide > Programmer's Guide > Advanced workbench concepts > Workbench key bindings.

Why can't I find the command I'm looking for?

  • To find commands which there are no keybindings:
Window > Preferences... > General > Keys
  [x] Include unbound commands
  • To find other commands, if the above didn't work:
Window > Preferences... > General > Keys > Advanced
  [ ] Filter action set contexts
  [ ] Filter internal contexts
  [ ] Filter uncategorized commands <-- this one is particularly useful

Why did Content Assist stop working?

First, select:

Window > Preferences... > General > Keys

Scroll to "Content Assist" and verify that CTRL-SPACE is still the hotkey. If it is, and Content Assist still doesn't work, several things can be the cause of this.

  • Non-English software or keyboards
  • Accessibility software such as screen readers
  • Background processes with key bindings

One known process that can interfere with CTRL-SPACE is Logitech's QuickCam10.exe. Upgrading to QuickCam 11 solves this problem. If you are not running this, try killing processes one by one until you get CTRL-SPACE back.

Why won't Content Assist work for my .xyz file type?

Make sure that you're opening the file with the correct editor. You may have several associated editors for a given file type, such as .php or .xml. Whatever was installed last is probably the default. If this is not your preferred editor, select:

Window > Preferences... > General > Editors > File Associations

and set a better default. Note that the last editor used will be used next time, so you might have to use Open With instead of Open.

If, for example, Content Assist works in your Java editor but not in your PHP editor, it could be a problem with your project's nature. See How do I manually assign a project Nature or BuildCommand?

How do I manually assign a project Nature or BuildCommand?

If your editor has a way to "add the xyz nature" to your project, such as via a context menu, use that. If not, here's another approach:

  • Create a new project of the type you need (such as PHP project or Java project or Plugin project)
  • Open the Navigator view
  • Open that new project's .project file.
  • Copy the <nature>s and <buildCommand>s from that .project into your actual project's .project file.

For a PHP project, this could be:


For a Plug-in project:


Note also:

  • the order of the natures is important. See bug 204883.
  • some natures may conflict, such as PDT and phpeclipse. You might have to disable one nature to use the other.
  • restarting Eclipse should not be necessary, but if in doubt, try closing and reopening the project or restart it with Eclipse with eclipse -clean.

How do I export a launch configuration?

Go into the 'Common' tab in your launch configuration and you will find a 'Browse' button to set the file that you want to export it as.

Starting from Eclipse 3.4, you can now export your launch configurations directly. Simply go File > Export... > Run/Debug > Launch Configurations.

How do I find out which workspace I currently have open?

You can append the -showLocation to your Eclipse shortcut/script or eclipse.ini file. If you are going to edit the eclipse.ini file, you should make sure that you put it on a new line that's before the -vmargs line (if such a line exists). Once you have restarted Eclipse, you should be able to see the path to your workspace in the Eclipse instance's window's title bar.

Why is Eclipse launching the current file I have open instead of whatever I last launched?

Eclipse 3.3 introduced a new feature named "Contextual Launching" which launches whatever you are currently working on or viewing. To get the old behaviour back wherein you always launch whatever you last launched, go to Window > Preferences > Run/Debug > Launching and then under Launch Operation select Always launch the previously launched application.

How do I configure Eclipse to use a black background with a white font?

For a consistent look, you have to use an operating system theme with a black background and white fonts. Alternatively, you can try setting the following preferences in eclipse:

  • Window > Preferences > General > Editors>Text Editors (foreground white, background black)

Note: Some editors specify their own colors, you may need to set the colors there as well.

Additionally, you will need to configure the syntax highlighting options for your editors. Here's how you do it for JDT:

  1. Window > Preferences > Java > Editor > Syntax Coloring
  2. For each rule that isn't enabled, enable it and set white as the color.
  3. For each rule that defines black as a color, set it to white.

Where do I find the javadoc for the Eclipse API locally? I don't always want to load stuff up in a browser.

See here.

Cut/Copy/Paste does not appear to be working properly on Linux. It's not often that I have to invoke the keyboard shortcut multiple times for it to take effect. What's the deal here?

You may be seeing an issue that's been logged to Eclipse as bug 153809 that appears to be caused by having Klipper or Glipper open. Please try disabling or closing the application and see if it resolves your problems.

How do I show line numbers in the Eclipse text editor?

See here.

How do I change the colour of the highlighting marker that highlights all the occurrences of some element in the text editor?

See here.

How do I switch my workspace?

Access the 'File' menu and then select the 'Switch Workspace' menu item.

I have just installed a plug-in but I do not see any indication of it in my workspace. What do I do?

See here.

How do I check for the command line invocation that Eclipse used to launch an application?

For example, I'm running an Ant task in Eclipse and it works great, but outside Eclipse it won't run. How can I see how Eclipse is running it?

See here.

Can projects exist outside of the workspace's folder?

Yes. Contrary to what many users are lead to believe, projects can physically exist outside of the workspace's folder. When you try to create a new project, you should be able to change the location of the project (and not have it be created in the workspace). If this change is not possible, it would be a missing feature and it is recommended to log the issue against the offending Eclipse plug-in.

You can also import projects via 'File > Import > General > Import Existing Projects into the Workspace'. Be sure to uncheck the copy checkbox at the bottom after selecting the source folder.

How do I change the list of workspaces listed under the 'Switch Workspace' submenu?

Starting in Eclipse 3.5, there is a preference page for this. See 'General > Startup and Shutdown > Workspaces'.

If you are in an older version of Eclipse, you can modify the eclipse/configuration/.settings/org.eclipse.ui.ide.prefs file by hand.

Java Development Tools (JDT)

The javadoc for the standard Java classes does not show up as context help. What is the problem? Should I download the javadocs?

To get the standard java javadoc to display in hover and context help in the Eclipse java editor, you need to run a JDK . Eclipse retrieves the javadoc from the JDK java sources. The sources are bundled with a JDK but not with a JRE. The file containing the sources in the SUN JDK is

What do you mean by 'run a JDK'?

The problem is that I've got unpacked java docs (and in archive too) at the proper location in the JDK dir and it is not displayed when working on java project...moreover javadoc specific to project is shown properly!

You need either to have the JDK set as the Java Runtime for your project or workspace, or have started Eclipse with that JDK. Make sure that the root dir of your JDK installation contains a file called

But it still does *not* work! Help me!

Make sure that you have selected the JDK in your workspace or project preferences. For the workspace check under Windows -> Preferences -> Java -> Installed JREs. For a project, check the project's properties.

How do I override the environment variables that Ant uses during execution?

To override environment variables passed to Ant, open your launch configuration.

  • On the 'JRE' tab choose 'Separate JRE'. Select the required JRE from the list.
  • On the 'Environment' tab, click 'Select' button then pick the variables you want to override from the list and click OK. Click 'Edit' to change values.

Why is Content Assist not working in the Java editor? Why doesn't Eclipse recognize my .java file as a Java file?

Please try the following steps:

  • Window > Preferences... (for Mac users: Eclipse > Preferences...)
  • Navigate to Java > Editor > Content Assist > Advanced
  • Ensure that all the entries in the uppermost list are checked.
  • Click 'Okay'.

Now check whether content assist is working again.

Note that for Eclipse to treat a .java file as a Java file with full syntax highlighting and code completion, it must be in a Java or Plug-in project, and located in a properly-defined source folder. Right-click your project's root folder and select properties to add more source folders if necessary, or move your file into the src/ tree.

Try creating a new Java project, then pasting your file into the src/ folder tree; or, try a new workspace (File > Switch Workspace... on a non-existent folder).

See also Manually assigning a projectNature or BuildCommand.

How do I change the Java compiler compliance level for my workspace?

See here.

How do I add arguments to the Java program I am running?

See here.

How do I alter my package representation so that parent packages are housing child packages?

See here.

I clicked on something and now I can only see the method that I am currently editing. What do I do? Did I lose my entire file?

See here.

I would like code completion to be activated as I type like how it works in Visual Studio? Can I turn this on somewhere?

No, this is currently not implemented. Please refer to bug 101420. You may also want to look at bug 159157.

I've been told that Eclipse has its own Java compiler, is this true? Can I use Sun's javac instead?

Yes, Eclipse's JDT project has its own compiler, named ECJ (Eclipse Compiler for Java). ECJ is the compiler that will be used when you save or invoke builds from within Eclipse. If you wish to use the javac compiler instead, you will have to use Apache Ant instead. On a slightly related topic, it is also possible to have Ant build with ECJ instead of with javac.

Plug-in Development

I get an unhandled event loop exception in my console. What gives?

See here.

A plug-in in my 'Eclipse Application' launch configuration is listed as being "out of sync", what should I do?

See here.


I cannot get the SWT widget ABC to work when I do XYZ. Could you help me?

Check the SWT Snippets section, there might be a code example that demonstrates what you are trying to

I cannot get Mozilla to run on Linux as an embedded browser?

Follow the instructions in the SWT FAQ.

I cannot get Firefox to run on Linux as an embedded browser?

Firefox is not supported as embedded browser on Linux for now. Take a look at bug #72487.

On some Linux distributions that dynamically link Firefox (like Ubuntu and Fedora), Firefox will work.


I am having some trouble with CVS in eclipse -- is there a way I can get actual logs and see detailed error messages?

Open the console view and select CVS from the triangle drop-down in the console toolbar.

Where are the CVS repositories locations stored?

In <workspace>/.metadata/.plugin/ . Previously used commit comments are in commitCommentHistory.xml.


What plug-ins are there for Subversion integration?

You can try either Subclipse or Subversive. Don't ask us which one is better. Some people use Subclipse, some people use Subversive.

I just installed Subversion on Mac/Linux, and then I installed Subclipse, but it does not work. What is the problem?

Verify that the version of Subclipse matches the version of Subversion that you have installed. Try uninstalling Subversion and configuring Subclipse's preferences to run JavaSVN. Take a look at the Subclipse FAQ. Ask on #subclipse for additional assistance.

I am trying to use svn+ssh:// with Subclipse, and it does not work?

Generally speaking, the JavaSVN adapter in the Team/SVN preferences will yield better results when using svn+ssh. See: Subclipse support for SVN protocols for detailed information.

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