Migrate from Eclipse to IntelliJ IDEA

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:

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 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

• Commit: 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 Shift+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.

Always select opened files

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.

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/Preferences | 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 | 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 Build 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 Build Project action.

To enable automatic compilation, navigate to Settings/Preferences | Build, Execution, Deployment | Compiler and select the Build 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 | Build Project Ctrl+F9.

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 Build option in your run configuration with Build, no error check:

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:

Quick-fixes

To apply a quick-fix in IntelliJ IDEA, press Alt+Enter:

All quick-fixes are based on inspections configured in Settings/Preferences | Editor | 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):

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 | Show the documentation popup 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:

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:

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 quickly 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 | Live Templates and use $SELECTION$ within the template text:

Navigation

The table below roughly maps the navigation actions available in Eclipse with those in IntelliJ IDEA:

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:

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:

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 Build in IntelliJ IDEA, try using a Maven goal or a Gradle task instead.

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/Preferences | 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 Manage branches).

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 Alt+9.

Checking projects out

To check out a project from a VCS, click Get from Version Control on the Welcome Screen, or in the main VCS menu.

Working with local changes

The Local Changes view 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.

Right-click the unversioned file or folder you want to ignore in the Local Changes tab of the Version Control tool window Alt+9 or in Project tool window and select Git | Add to .gitignore or Git | Add to .git/info/exclude.

If you want ignored files to be also displayed in the Local Changes tab of the Version Control tool window, click on the toolbar and select Show Ignored Files.

Working with history

The Log tab of the Git 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+`, or the widget on the right of the status bar:

All VCS operations are available from the VCS main menu:

What configuration is needed before start?

A lot of IntelliJ IDEA features are available without any configuration right after you launch it. Still, to take full advantage of running your PHP application, you need to configure a PHP interpreter and a server.

If you plan to launch the application locally, you need a PHP engine installed and registered in IntelliJ IDEA, as well as a Web server installed, configured, and integrated with IntelliJ IDEA. You can install these components separately or use an AMP package. For more details about initial environment configuration, refer to Configure PHP development environment.

If you are going to run and debug an application directly on a remote host, the only thing you need is register access to this host in IntelliJ IDEA to enable synchronization.

How do I start with deployment to a remote host?

If you've checked out your project from the remote host, the deployment server is already configured. Otherwise, you will need to get it configured (it can be FTP/SFTP/FTPS server or mounted/local folder) on the Deployment page of the Settings/Preferences dialog. The Remote host tool window is available on the right-hand side of the IntelliJ IDEA window, which can be handy for browsing through your remote server and performing various actions.

See Deploy your application for details.

How do I start debugging?

IntelliJ IDEA comes with support for both Xdebug and Zend Debugger for debugging and profiling. There is a zero-configuration debugging workflow available, which means that to start debugging you only need to:

• Click Start Listening for PHP Debugging Connections on the toolbar of the IDE.

• Place a breakpoint in code by clicking in the editor gutter next to the line.

• Start debugging in the browser using a plugin or browser bookmarklets.