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Revision as of 14:39, 11 September 2007 by (Talk | contribs) (reformat long question)

A collection of FAQs gathered in the Eclipse IRC channels.



What are #eclipse and #eclipse-dev about?

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

  • #azureus about Azureus, an Eclipse-based BitTorrent client
  • #easyeclipse about EasyEclipse, an Eclipse distribution
  • #phpeclipse about PHPEclipse, an Eclipse-based IDE for PHP
  • #radrails about RadRails, an Eclipse plug-in for Ruby on Rails development
  • #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

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 the Eclipse Bugzilla. 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, More FAQs
  2. Learn about the tools/projects you use from their websites or wiki pages
  3. Ask a question in 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


Where are Eclipse's log files located at?

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

First, clean your projects using the menu item Project/Clean to trigger a rebuild.

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.

What's the key for ...?

The most convenient two key bindings are:

  • 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's a few others:

  • CTRL-F6 / SHIFT-CTRL-F6: Cycle editor windows forwards / 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.

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.

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.

Installation, Startup and Runtime

I'm new, what should I read first?

Where can I get Eclipse?

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

What is the Update Manager?

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:

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). Then 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

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

What other commandline arguments are available?

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. Eclipse has a list of reference platforms that it is tested against which you should try to match against. These issues are usually related to Blackdown or GCJ. Try installing one from Sun or IBM (eg., Sun JDK 5.0 or IBM JDK 5.0) and make sure that it is the one being used by starting Eclipse with an additional argument:
eclipse -vm /full/path/to/java/bin/java

The argument must point to the java or javaw executable.

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

I just installed Eclipse on Linux 64, but it does not start. What is the problem?

Make sure that you have downloaded the 64-bit version of Eclipse and have installed a Sun 64-bit JVM


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.

Version Control

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.

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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