Eclipse IDE

Installation

There are generally three ways to install Eclipse:

• Manually from Eclipse Downloads
• Via a package manager (snapcraft, pacman, etc.)
• The Eclipse Installer

Also see the official installation guide.

Recommended installation locations

On Linux:

• /home/shadylady/tools/eclipse/eclipse-java
• /opt/eclipse (according to Linux#Manualsoftwareinstallation)
• /usr/lib/eclipse  (This is only if installed by an official system package manager)
• /snap/eclipse/current  (If installed via snap )

On Windows:

• C:\ProgramData\eclipse\eclipse-java 

The Eclipse INI Configuration File

Eclipse is launched with settings specified in an INI file in the installation directory called eclipse.ini. See the official eclipse.ini documentation. Changes to the INI file will take effect upon the next restart of Eclipse.

When Eclipse is installed via snap

There is no way to edit eclipse.ini when Eclipse is installed via snap. Workarounds include:

• Use the --launcher.ini /path/to/eclipse.ini option.
• Pass individual settings via -vmargs -Xms1g -Xmx3g  to the launcher.

Selecting a JVM

Eclipse 2020+ requires to run with a Java 11 VM or higher.  If you need to set which JRE Eclipse runs with, add the following lines to the eclipse.ini.

-vm
/path/to/jdk

Workspaces

It is not recommended to put your code in a workspace directory. A "workspace" in Eclipse is more akin to isolated or "portable" application settings; not a place to store projects.

Potential workspace locations:

• ~/tools/eclipse/workspace    (Linux)
• ~/.config/eclipse/workspace 
• C:\ProgramData\eclipse\workspace      (Windows)

Configuration

Application memory

Eclipse will perform terribly unless you give it a few GB of memory (RAM).

Ensure the eclipse.ini contains the following JVM options:

-Xms512m
-Xmx2g

The values above are just an example. Scale them to fit your needs.

Create a desktop launcher

If Eclipse was installed manually, you'll want to create a desktop application launcher or shortcut. See Linux#Desktopentries.

An example eclipse.desktop  file in Linux you could put in ~/.local/share/applications/:

[Desktop Entry]
Name=Eclipse
Comment=Java Development Environment
Icon=/opt/eclipse/icon.xpm
Exec=/opt/eclipse/eclipse
Terminal=false
Type=Application
Categories=Development;IDE;Java;
StartupNotify=true

Disable Welcome menu

To disable the Welcome menu from consuming the full application screen on startup:

• Clear "Always show Welcome at start up" at the bottom right corner of the Welcome menu.

General settings

In Window > Preferences > General:

• Set "Show heap status"

Editor settings

In Window > Preferences > General > Editors

Text Editors:

• Set "Displayed tab width" to "3"
• In "Spelling", clear "Enable spell checking"

Workspace settings

In Window > Preferences > General > Workspace:

• Set "Refresh using native hooks or polling"
• Set "Show full workspace path"
• Set "Text file encoding" to "UTF-8"
• Set "New text file line delimiter" to "Unix"

Expand Workspace > Build.  Set "Save automatically before build"

Gradle settings

In Window >Preferences > Gradle:

• See below: Importing Gradle Projects

Java settings

In Window > Preferences > Java:

Code Style > Formatter:

• Click "Import..." and import IHMC Open Robotics Software/ihmc-java-toolkit/CodeFormatTemplates/IHMCEclipseFormatter.xml

Compiler > Error/Warnings > Deprecated and restricted API:

• Set "Forbidden reference (access rules)" to "Ignore"

Editor > Content Assist > Favorites:

• Click "New Type..." and add "org.junit.jupiter.api.Assertions"

Templates

In Editor > Templates:

Set up Installed JREs

See also the page on Java.

In Java > Installed JREs, add any manually installed JREs. (i.e. Zulu in the /opt/zulu directory)

Check to make sure the jfxrt.jar is present for JavaFX to work.

In the "Edit JRE" dialog, expand the *.jar entries and check if a Source attachement is detected. These should be detected automatically.

Plugins

JavaFX

To get JavaFX to work in Eclipse, a plugin is presently required. Follow the instructions to install e(fx)clipse:

1. Go to Help > Eclipse Marketplace...
2. Then search and install efxclipse

ANSI Color Console

This plugin provides nice log level coloring in the console as supported by IHMC's Log Tools library.

Search "ansi console" in the Marketplace and install ANSI Escape in Console by Mihai Nita.

C++ development

CMake editor: http://www.cthing.com/CMakeEd.asp

Eclipse file generator from CMake: https://gitlab.kitware.com/cmake/community/wikis/doc/editors/Eclipse-CDT4-Generator

EGit

Install Egit: http://www.eclipse.org/egit/download/

Set Git default Pull to 'rebase' as described in Git Tips And Tricks

In Window > Preferences > Team > Git > History:

• Set "Maximum characters to show for a tag" to 100
• Set "Maximum characters to show for a branch" to 100

Importing Gradle Projects

1. Select File > Import...
2. Select the "Gradle > Existing Gradle Project" import wizard
3. Clear "Show the welcome page the next time the wizard appears"
4. Set the "Project root directory"
5. Select "Override workspace settings"
   1. Set "Gradle distribution" to "Local installation directory" and point to your local Gradle installation
      (Common locations are /usr/share/java/gradle, /opt/gradle, and C:\gradle)
   2. Set "Show Console View"
   3. Set "Show Executions View"
6. (passive) Check that a tree populates on the "Import Preview" page

See Gradle#Troubleshooting

Troubleshooting

General troubleshooting steps for Eclipse are:

• Project > Rebuild
• Project > Clean...
• Gradle > Refresh Gradle Project
• File > Restart
• Create a new workspace

Adding and removing projects from workspace

It might be best to delete projects in Eclipse before deleting them on disk. Else your workspace might get corrupted if you try to delete from the File Explorer.

NoClassDefFoundError

Sometimes Eclipse will "forget" part of it's classpath. Recommended solution: Refresh Gradle Project

Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.NoClassDefFoundError: com/martiansoftware/jsap/JSAPException
	at java.lang.Class.getDeclaredMethods0(Native Method)
	at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
	at java.lang.Class.privateGetMethodRecursive(Class.java:3048)
	at java.lang.Class.getMethod0(Class.java:3018)
	at java.lang.Class.getMethod(Class.java:1784)
	at sun.launcher.LauncherHelper.validateMainClass(LauncherHelper.java:544)
	at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:526)
Caused by: java.lang.ClassNotFoundException: com.martiansoftware.jsap.JSAPException
	at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	... 7 more

See also

TODO: How to run Gradle tasks with custom options

Learn more