Overview
Switching from Eclipse to IntelliJ IDEA, especially if you've been using Eclipse for a long time, requires understanding some fundamental differences between the two IDEs, including their , , , project configuration and other aspects.
User Interface
No workspace
The first thing you'll notice when launching IntelliJ IDEA is that it has no workspace concept. This means that you can work with only one project at a time. While in Eclipse you normally have a set of projects that may depend on each other, in IntelliJ IDEA you have a single project that consists of a set of modules.
If you have several unrelated projects, you can open them in separate windows.
If you still want to have several unrelated projects opened in one window, as a workaround you can configure them all in IntelliJ IDEA as modules.
IntelliJ IDEA vs Eclipse terminology
The table below compares the terms in Eclipse and IntelliJ IDEA:
EclipseIntelliJ IDEA
WorkspaceProject
ProjectModule
FacetFacet
LibraryLibrary
JRESDK
Classpath variablePath variable
No perspectives
The second big surprise when you switch to IntelliJ IDEA is that it has no perspectives.
It means that you don't need to switch between different workspace layouts manually to perform different tasks. The IDE follows your context and brings up the relevant tools automatically.
Tool windows
Just like in Eclipse, in IntelliJ IDEA you also have tool windows. To open a tool window, simply click it in the tool window bar:
If the tool window bar is hidden, you can open any tool window by hovering over the corresponding icon in the bottom left corner:
If you want to make the tool window bar visible for a moment, you can press Alt (Cmd for macOS) twice and hold it.
If you don't want to use the mouse, you can always switch to any toolbar by pressing the shortcut assigned to it. The most important shortcuts to remember are:
Project: Alt 1
Version Control: Alt 9
Terminal: Alt F12
Another thing about tool windows is that you can drag, pin, unpin, attach and detach them:
To help store/restore the tool windows layout, there are two useful commands:
Window | Store Current Layout as Default
Window | Restore Default Layout (also available via Ctrl F12)
Multiple windows
Windows management in IntelliJ IDEA is slightly different from Eclipse. You can't open several windows with one project, but you can detach any number of editor tabs into separate windows.
Auto-scrolling to/from sources
By default, IntelliJ IDEA doesn't change the selection in the
Project Tool Window when you switch between editor tabs. However, you can enable it in the tool window settings:
Enabling line numbers
Line numbers are not shown in the editor by default. To enable them, go to Settings/Preferences | Editor | General | Appearance | Show line numbers. There you will also find other useful settings.
General workflows
No 'save' button
Time for some really shocking news: IntelliJ IDEA has no Save button. Since in IntelliJ IDEA you can undo refactorings and revert changes from
Local History, it makes no sense to ask you to save your changes every time.
Still, it's worth knowing that physical saving to disk is triggered by certain events, including compilation, closing a file, switching focus out of the IDE, etc. You can change this behavior via Settings | Appearance & Behavior | System Settings:
No save actions
One of the features you may miss in IntelliJ IDEA as an Eclipse user is save actions, i.e. the actions triggered automatically on save, such as reformatting code, organizing imports, adding missing annotations and the final modifier, etc. Instead, IntelliJ IDEA offers you to run the corresponding actions automatically on commit:
Or manually:
Code | Reformat Code (Ctrl Alt L)
Code | Optimize Imports (Ctrl Alt O)
Analyze | Code Cleanup
If, for some reason, you can't live without an Eclipse save action, you can install a
plugin that imitates Eclipse save actions.
Compilation
The way IntelliJ IDEA compiles projects is different from Eclipse in a number of ways.
Auto-compilation
By default, IntelliJ IDEA doesn't automatically compile projects on saving because normally we don't invoke the save action explicitly in IntelliJ IDEA.
If you want to mimic the Eclipse behavior, you can invoke the Make Project action (Ctrl F9) - it will save the changed files and compile them. For your convenience, you can even reassign the Ctrl S shortcut to the Make Project action.
To enable automatic compilation, navigate to Settings/Preferences | Build, Execution, Deployment | Compiler and select the Make project automatically option:
Note that automatic compilation in IntelliJ IDEA differs from that in Eclipse. In Eclipse it's not fully automatic, as it is triggered by the save action invoked by the user explicitly, whereas in IntelliJ IDEA it is invoked implicitly when you type in the editor.
This is why, even if the Make project automatically option is enabled, IntelliJ IDEA doesn't perform automatic compilation if at least one application is running: it will reload classes in the application implicitly. In this case you can call Build | Make Project (Ctrl F9).
Problems tool window
The
Problems tool window appears if the Make project automatically option is enabled in the
Compiler settings. It shows a list of problems that were detected on project compilation:
Eclipse compiler
While Eclipse uses its own compiler, IntelliJ IDEA uses the javac compiler bundled with the project JDK. If you must use the Eclipse compiler, navigate to Settings/Preferences | Build, Execution, Deployment | Compiler | Java Compiler and select it as shown below:
The biggest difference between the Eclipse and javac compilers is that the Eclipse compiler is more tolerant to errors, and sometimes lets you run code that doesn't compile.
In situations when you need to run code with compilation errors in IntelliJ IDEA, replace the Make option in your
run configuration with Make, no error check:
Shortcuts
IntelliJ IDEA shortcuts are completely different from those in Eclipse.
If you choose a keymap specific to your operating system (Default for Windows/Linux or macOS 10.5 for macOS), there may be conflicts between shortcuts used in IntelliJ IDEA and your OS. To avoid such conflicts, we recommend tweaking your OS shortcut settings (refer to
Keymap for more details).
The table below shows how the top Eclipse actions (and their shortcuts) are mapped to IntelliJ IDEA (you may want to print it out to always have it handy).
EclipseIntelliJ IDEA
Action Shortcut Action Shortcut
Code completion Ctrl Space Basic completion Ctrl Space
-- Smart completion Ctrl Shift Space
-- Statement completion Ctrl Shift Enter
Quick access Ctrl 3 Search everywhere Shift x 2
Maximize active view or editor Ctrl M Hide all tool windows Ctrl Shift F12
Open type Ctrl Shift T Navigate to class Ctrl N
Open resource Ctrl Shift R Navigate to file Ctrl Shift N
-- Navigate to symbol Ctrl Shift Alt N
Next view Ctrl F7 --
-- Recent files Ctrl E
-- Switcher Ctrl Tab
Quick outline Ctrl O File structure Ctrl F12
Move lines Alt Up/Down Move lines Shift Alt Up/Shift Alt Down
Delete lines Ctrl D Delete lines Ctrl Y
Quick fix Ctrl 1 Show intention action Alt Enter
Quick switch editor Ctrl E Switcher Ctrl Tab
-- Recent files Ctrl E
Quick hierarchy Ctrl T Navigate to type hierarchy Ctrl H
-- Navigate to method hierarchy Ctrl Shift H
-- Show UML popup Ctrl Alt U
Last edit location Ctrl Q Last edit location Ctrl Shift Backspace
Next editor Ctrl F6 Select next tab Alt Right
Run Ctrl Shift F11 Run Shift F10
Debug Ctrl F11 Debug Shift F9
Correct indentation Ctrl I Auto-indent lines Ctrl Alt I
Format Ctrl Shift F Reformat code Ctrl Alt L
Surround with Ctrl Alt Z Surround with Ctrl Alt T
-- Surround with live template Ctrl Alt J
Open declaration F3 Navigate to declaration Ctrl B
-- Quick definition Ctrl Shift I
Open type hierarchy F4 Navigate to type hierarchy Ctrl H
-- Show UML popup Ctrl Alt U
References in workspace Ctrl Shift G Find usages Alt F7
-- Show usages Ctrl Alt F7
-- Find usages settings Ctrl Shift Alt F7
Open search dialog Ctrl H Find in path Ctrl Shift F
Occurrences in file Ctrl Alt U Highlight usages in file Ctrl Shift F7
Copy lines Ctrl Alt Down Duplicate lines Ctrl D
Extract local variable Ctrl Alt L Extract variable Ctrl Alt V
Assign to field Ctrl 2/Ctrl F Extract field Ctrl Alt F
Show refactor quick menu Ctrl Alt T Refactor this Ctrl Shift Alt T
Rename Ctrl Alt R Rename Shift F6
Go to line Ctrl L Navigate to line Ctrl G
Structured selection Shift Alt Up/Shift Alt Down Select word at caret Ctrl W/Ctrl Shift W
Find next Ctrl J Find next F3
Show in Ctrl Alt W Select in Alt F1
Back Ctrl [ Back Ctrl Alt Left
Forward Ctrl ] Forward Ctrl Alt Right
Eclipse keymap
For Eclipse users who prefer not to learn new shortcuts, IntelliJ IDEA provides the Eclipse keymap which closely mimics its shortcuts:
Find action
When you don't know the shortcut for some action, try using the Find action feature available via Ctrl Shift A. Start typing to find an action by its name, see its shortcut, or call it:
Coding assistance
Both Eclipse and IntelliJ IDEA provide coding assistance features, such as code completion, code generation, quick-fixes, live templates, etc.
Quick-fixes
To apply a quick-fix in IntelliJ IDEA, press Alt Enter:
All quick-fixes are based on inspections configured in Settings | Inspections:
If you want to apply a quick-fix to several places at once (i.e. to a whole folder, module or even a project), you can do it by running the corresponding inspection via Analyze | Run Inspection By Name or by running the whole batch of inspections via Analyze | Inspect Code:
Apart from outright problems, IntelliJ IDEA also recognizes code constructs that can be improved or optimized via the so-called intentions (also available with Alt Enter):
EclipseIntelliJ IDEA
ActionShortcutActionShortcut
Quick fixCtrl 1Show intention actionAlt Enter
Generating code
The key action for generating code is Code | Generate, available via Alt Insert:
This action is context-sensitive and is available not only within the editor, but also in the
Project Tool Window and the
Navigation bar:
Code completion
IntelliJ IDEA provides several different types of code completion, which include:
Basic completion
Second basic completion
Smart completion
Second smart completion
Statement completion
To learn more about the differences between these completion types, refer to
Top 20 Features of Code Completion in IntelliJ IDEA.
By default, IntelliJ IDEA doesn't show the Documentation popup for the selected item, but you can enable it in Settings/Preferences | Editor | Code Completion | Autopopup documentatoin in (ms):
If you don't want to enable this option, you can manually invoke this popup by pressing Ctrl Q when you need it:
When the caret is within the brackets of a method or a constructor, you can get the info about the parameters by calling Parameter Info with Ctrl P:
EclipseIntelliJ IDEA
ActionShortcutActionShortcut
Code completionCtrl SpaceBasic completionCtrl Space
--Smart completionCtrl Shift Space
--Statement completionCtrl Shift Enter
Templates
You may be used to typing main in the editor and then calling code completion to have it transformed into a main method definition. However, IntelliJ IDEA templates are a little different:
TemplateEclipseIntelliJ IDEA
Define a main methodmainpsvm
Iterate over an arrayforitar
Iterate over a collectionforitco
Iterate over a listforitli
Iterate over an iterable using foreach syntaxforeachiter
Print to System.outsysoutsout
Print to System.errsyserrserr
Define a static fieldstatic_finalpsf
The list of available templates can be found in Settings/Preferences | Editor | Live Templates. There you can also add your own templates or modify any existing ones.
While IntelliJ IDEA suggests templates in code completion results, you can quckly expand any template without using code completion simply by pressing Tab.
Postfix templates
In addition to 'regular' templates, IntelliJ IDEA offers the so-called postfix templates. They are useful when you want to apply a template to an expression you've already typed. For instance, type a variable name, add .ifn and press Tab. IntelliJ IDEA will turn your expression into a if (...==null){...} statement.
To see a complete list of available postfix templates, go to Settings/Preferences | Editor | General | Postfix Completion.
Surround with live template
The surround with templates is another addition that works similarly to live templates but can be applied to the selected code with Ctrl Alt J.
To define your own surround with template, go to Settings/Preferences | Editor | General | Live Templates and use $SELECTION$ within the template text:
$LOCK$.readLock().lock();try { $SELECTION$ } finally { $LOCK$.readLock().unlock();}
Navigation
The table below roughly maps the navigation actions available in Eclipse with those in IntelliJ IDEA:
EclipseIntelliJ IDEA
ActionShortcutActionShortcut
Quick accessCtrl 3Search everywhereShift x 2
Open typeCtrl Shift TNavigate to classCtrl N
Open resourceCtrl Shift RNavigate to fileCtrl Shift N
--Navigate to symbolCtrl Shift Alt N
Quick switch editorCtrl ESwitcherCtrl Tab
--Recent filesCtrl E
Open declarationF3Navigate to declarationCtrl B
Open type hierarchyF4Navigate to type hierarchyCtrl H
--Show UML popupCtrl Alt U
Quick outlineCtrl OFile structureCtrl F12
BackCtrl [BackCtrl Alt Left
ForwardCtrl ]ForwardCtrl Alt Right
Later, when you get used to these navigation options and need more, refer to
Top 20 Navigation Features in IntelliJ IDEA.
Refactorings
The following table maps the shortcuts for the most common refactorings in Eclipse with those in IntelliJ IDEA:
EclipseIntelliJ IDEA
ActionShortcutActionShortcut
Extract local variableCtrl Alt LExtract variableCtrl Alt V
Assign to fieldCtrl 2Extract fieldCtrl Alt F
Show refactor quick menuCtrl Alt TRafactor thisCtrl Shift Alt T
RenameCtrl Alt RRenameShift F6
To learn more about many additional refactorings that IntelliJ IDEA offers, refer to
Top 20 Refactoring Features in IntelliJ IDEA Undo
Sometimes, refactorings may affect a lot of files in a project. IntelliJ IDEA not only takes care of applying changes safely, but also lets you revert them. To undo the last refactoring, switch the focus to the
Project Tool Window and press Ctrl Z.
Search
Below is a map of the most common search actions and shortcuts:
EclipseIntelliJ IDEA
ActionShortcutActionShortcut
Open search dialogCtrl HFind in pathCtrl Shift F
References in workspaceCtrl Shift GFind usagesAlt F7
--Show usagesCtrl Alt F7
--Find usages settingsCtrl Shift Alt F7
Occurrences in fileCtrl Alt UHighlight usages in fileCtrl F7
Code formatting
IntelliJ IDEA code formatting rules (available via Settings/Preferences | Editor | Code Style) are similar to those in Eclipse, with some minor differences. You may want to take note of the fact that the Using the Tab char option is disabled by default, the Indent size may be different, etc.
Note that if the Eclipse formatter settings cannot be imported, the following error message shows up:
The input file is not a valid Eclipse XML profile.
If you would like to import your Eclipse formatter settings, go to Settings/Preferences | Editor | Code Style | Java, click Manage, click Import and select the exported Eclipse formatter settings (an XML file).
Note that there may be some discrepancies between the code style settings in IntelliJ IDEA and Eclipse. For example, you cannot tell IntelliJ IDEA to put space after (but not before). If you want IntelliJ IDEA to use the Eclipse formatter, consider installing the
Eclipse code formatter plugin.
EclipseIntelliJ IDEA
ActionShortcutActionShortcut
FormatCtrl Shift FReformat codeCtrl Alt L
Running and reloading changes
Similarly to Eclipse, IntelliJ IDEA also has
Run/Debug Configurations that you can access either form the main toolbar, or the main menu. Compare the related shorcuts:
EclipseIntelliJ IDEA
ActionShortcutActionShortcut
RunCtrl Shift F11RunShift F10
DebugCtrl F11DebugShift F9
--MakeCtrl F9
--Update applicationCtrl F10
As mentioned before, by default IntelliJ IDEA doesn't compile changed files automatically (unless you configure it to do so). That means the IDE doesn't reload changes automatically. To reload changed classes, call the Make action explicitly via Ctrl F9. If your application is running on a server, in addition to reloading you can use the Update application action via Ctrl F10:
Debugging
The debuggers in Eclipse and IntelliJ IDEA are similar but use different shortcuts:
EclipseIntelliJ IDEA
ActionShortcutActionShortcut
Step intoF5Step intoF7
--Smart step intoShift F7
Step overF6Step overF8
Step outF7Step outShift F8
ResumeF8ResumeF9
Toggle breakpointCtrl Shift BToggle breakpointCtrl F8
--Evaluate expressionAlt F8
Working with Application Servers (Tomcat/TomEE, JBoss EAP, Glassfish, WebLogic, WebSphere)
This feature is supported in the Ultimate edition only.
Deploying to application servers in IntelliJ IDEA is more or less similar to what you are probably used to in Eclipse. To deploy your application to a server:
Configure your
artifacts via Project Structure | Artifacts (done automatically for Maven and Gradle projects).
Configure an application server via Settings | Application Servers.
Create a
run configuration, and then specify the artifacts to deploy and the server to deploy to.
You can always tell the IDE to build/rebuild your artifacts once the have been configured via Build | Build Artifacts.
Working with Build Tools (Maven/Gradle)
IntelliJ IDEA doesn't provide visual forms for editing Maven/Gradle configuration files. Once you've imported/created your Maven/Gradle project, you are free to edit its pom.xml/build.gradle files directly in the editor. Later, you can tell IntelliJ IDEA to
synchronize the project model with the changed files on demand, or
automatically import changes to the new build files. Any changes to the underlying build configuration will eventually need to be synced with the project model in IntelliJ IDEA.
For operations specific to Maven/Gradle, IntelliJ IDEA provides the
Maven Project tool window and the
Gradle tool window. Apart from your project structure, these tool windows provide a list of goals/tasks plus a toolbar with the relevant actions.
If you want the IDE to synchronize your changes immediately:
For pom.xml, enable the corresponding options in Settings | Build, Execution, Deployment | Build Tools | Maven | Importing | Import Maven projects automatically
For build.gradle, enable the corresponding option in Settings | Build, Execution, Deployment | Build Tools | Gradle | Use auto-import.
For manual synchronization, use the corresponding action on the Maven/Gradle tool window toolbar:
.
Running goals/tasks
Use the Maven/Gradle tool window to run any project goal/task. When you do, IntelliJ IDEA creates the corresponding run configuration which you can reuse later to run the goal/task quickly.
It's worth mentioning that any goal/task can be attached to be run before a Run Configuration. This may be useful when your goal/task generates specific files needed by the application.
Both the Maven and Gradle tool windows provide the Run Task action. It runs a Maven/Gradle command similarly to how you'd run it using the console.
Configuring artifacts
If you have WAR artifacts configured in your pom.xml/build.gradle file, IntelliJ IDEA automatically configures the corresponding artifacts in Project Structure | Artifacts.
Note that when you compile your project or build an artifact, IntelliJ IDEA uses its own build process which may be faster, but is not guaranteed to be 100% accurate. If you notice inconsistent results when compiling your project with Make in IntelliJ IDEA, try using a Maven goal or a Gradle task instead.
Working with VCS (Git, Mercurial, Subversion, Perforce)
Configuring VCS roots
When you open a project located under a VCS root, IntelliJ IDEA automatically detects it and suggests adding this root to the project settings. To change version control-related project settings (or manually add a VCS root), go to Settings | Version Control:
IntelliJ IDEA works perfectly with multi-repository projects. Just map your project directories to VCS, and the IDE will take care of the rest. For
Git and
Mercurial, the IDE will even offer you synchronized branch control, so that you can perform branch operations on multiple repositories simultaneously (for more details, see
Git Branches in Multirooted Projects).
Editing VCS settings
Every VCS may require specific settings, for example, Path to Git executable, GitHub/Perforce credentials, etc.:
Once you've configured the VCS settings, you'll see the
Version Control tool window. You can invoke it any time by pressing Alt 9.
Checking projects out
To check out a project from a VCS, click Checkout from Version Control on the
Welcome Screen, or in the main VCS menu.
Working with local changes
The
Local Changes tab of the
Version Control tool window shows your local changes: both staged and unstaged. To simplify managing changes, all changes are organized into changelists. Any changes made to source files are automatically included into the active changelist. You can create new changelists, delete the existing ones (except for the Default changelist), and move files between changelists.
To configure ignored files, go to Settings | Version Control, or use the corresponding button in the Version Control tool window.
Working with history
The
Log tab of the
Version Control tool window lets you see and search through the history of commits. You can sort and filter commits by the repository, branch, user, date, folder, or even a phrase in the description. You can find a particular commit, or just browse through the history and the branch tree:
Working with branches
IntelliJ IDEA lets you create, switch, merge, compare and delete branches. For these operations, either use Branches from the main or context VCS menu, or the VCS operations popup (you can invoke it by pressing Alt Back Quote, or the widget on the right of the status bar:
All VCS operations are available from the VCS main menu:
ActionShortcut
Version Control tool window Alt 9
VCS operations popup Alt Back Quote
Commit changes Ctrl K
Update project Ctrl T
Push commits Ctrl Shift K
Importing an Eclipse project to IntelliJ IDEA
Despite these differences in terms and the UI, you can import either an Eclipse workspace or a single Eclipse project. To do this, click Import Project on the Welcome Screen, or select File | New | Project from Existing Sources in the main menu.
If your project uses a build tool such as
Maven or
Gradle, we recommend choosing the corresponding option when prompted in the
Import Project wizard, and selecting the associated build file (pom.xml or build.gradle):
If you'd like to import your existing run configurations from Eclipse, consider using this
third-party plugin.
Last modified: 30 August 2017
Exporting an IntelliJ IDEA Project to Eclipse See Also
How tos:
Exporting an IntelliJ IDEA Project to Eclipse Discover IntelliJ IDEA