(Former) IntelliJ Notes
Russell Bateman
Notes I make as I'm forced to use this IDE. I know others think it's wonderful,
but I'm an Eclipse guy and see no reason to change over were it not for my
new employer forcing me to.
Setting up IntelliJ
What's crucial is:
Ensure Maven set-up is working. IntelliJ relies on Maven.
Ensure that JAVA_ROOT points to a JDK (and not merely a JRE).
What signals the difference is that ${JAVA_HOME} /libtools.jar . If not, then it's a JRE not a JDK. IntelliJ will not run
without this JAR and will tell you so.
Structure in IntelliJ—Outline in Eclipse
What's called Outline in Eclipse is a side-ways control in the left
margin in IntelliJ. The way it works actually makes sense and leads to
something to think about in the way I lay out my Eclipse panes.
Get Outline details of current file: Try adding Outline view
to left-most pane (Package /Project Explorer views)
à la IntelliJ. This may work better because when the
current file's outline interests you, no other files do so you can sacrifice
the Package, Project or Navigator views for the time you're doing that.
Miscellaneous stuff in IntelliJ
To bring up a heretofore unused project from the filesystem into IntelliJ,
File -> Open -> browse for pom.xml in the new project.
Keys...
Key
Description of function
Eclipse equivalent
Ctrl N
brings up search dialog to look for resources,
classnames, etc.
Shift Ctrl R/T
Ctrl Alt B
Pop-up list of implementations of the interface under
cursor.
?
Ctrl Y
Deletes the current line.
Ctrl D
Autoscroll from/to Source
under cogwheel in Project title bar.
(icon in Project Explorer top bar)
Show diff
just go to the filesystem and use git diff .
Shift-Ctrl-F
Find all throughout project (via menu Eit → Find →
Find in Path
Ctrl-H
Configuring keyboard shortcuts
Too long used to Ctrl-D for "delete line", I had to remap it in
IntelliJ which prefers Ctrl-Y and uses Ctrl-D for "duplicate
line" (an action I don't use). Despite this, it's a good example for any other
re-mapping you want to make.
File -> Settings... .
Look down the left pane for IDE Settings -> Keymap .
Click Copy ; name the new Keymaps ; I called mine
Russ .
Look for Delete Line which is mapped to Ctrl-Y .
Right-click and choose Remove Ctrl-Y ; this will stop IntelliJ
from continuing to use Ctrl-Y for deleting a line.
Right-click again and choose Add Keyboard Shortcut .
Type Ctrl-D .
In order for this to work now, you must also do the following steps:
Look for Duplicate Line or Block which is mapped to
Ctrl-D .
Right-click and choose Remove Ctrl-D ; this will stop IntelliJ
from continuing to use Ctrl-D for duplicating a line or block of
text.
Do not map Duplicate Line or Block to anything (unless you want
to).
Other keyboard shortcuts to rewire include Last Edit Location , Eclipse
uses Alt+Left , Next Edit Location , Eclipse uses Alt+Right .
Here are some mappings to contemplate.
Turn on line numbers and off vertical guides
Here's how to turn line numbers on permanently and remove vertical indent
guides (those annoying vertical lines in the editor).
File -> Settings... .
Look down the left pane for IDE Settings -> Editor .
Look for Appearance .
How to invoke diff for a file
Look to bottom of workbench, click on Changes .
Right-click on Default or the file you wish to see.
Choose Show Diff .
A missing class...
Symptom
A class is missing even when the import statement is typed in by hand (and
valid).
Analysis
The JAR containing the class is missing (duh).
Solution
The JAR must be included in the module's pom.xml . The JAR may be known
to other modules in the project. Here's how to add it to the current module
where it's missing:
Figure out which JAR supplies the missing symbol:
Right-click the project root—that is, the top-level project (and
not the module missing the symbol).
Choose Find in Path and narro the search to pom.xml
files.
Choose a good occurrence in the resulting search output list.
Copy the whole dependency.
Open pom.xml (in the module missing the JAR/symbol) and paste in
the new dependency clause.
Open Maven Projects view (right-hand margin of IntelliJ
workbench) and click the reload button (circling arrows at upper-left of
view).
Note that a module may not be missing the symbol and yet not define the
dependency because it inherits dependencies from the project (root)
pom.xml as long as it defines none of its own.
Solving the nasty propensity to collapse import lists into wildcards
IntelliJ loves to corrupt import statements by collapsing like package names
down and discarding all the classnames in favor of using a wildcard (*). To
turn this off, I apparently had to set the number of imports up to 99 in:
File -> Settings -> Code Style -> Java -> Class count to use import with '*'
Names count to use static import with '*'
Method returns in Java code
Hovering over a method will not, as in Eclipse, tell you anything about it.
Instead, holding down the Ctrl key and hovering will tell you or hovering and
pressing Ctrl-Q will get you the Javadoc.
Attaching source code
Here's how to attach sources in IntelliJ. This is one thing that's easier and
more successful in IntelliJ than in Eclipse.
Click link Attach Sources .
In the Attach Sources dialog, navigate to the root of the project
containing the source code, e.g.: project ct .
Click OK .
See "Scanning for roots"; choose a root or, for all source code, click
OK (since all are selected).
Enjoy population of editor window with source code.
Sorting out Eclipse problems in code from IntelliJ
Actually, Maven-organized code from IntelliJ. This is about the pains of trying
to keep Eclipse going on the side.
Bad title here, but this was one of the main problems I ran up against when
trying to get some code working in Eclipse. All the warnings I was able to
sort out using Window -> Preferences -> Java -> Compiler ->
Errors/Warnings.
Below I seem to waffle on whether it's one project or many. This is because I'm
trying to write generically, but in fact, I'm working on what is multiple
modules in a hierarchy in IntelliJ. In Eclipse, they are simply sibling
projects (how they also appear in IntelliJ).
Steps
Create a clean Eclipse workspace.
In (main) project, tell Maven to create Eclipse project(s). Make sure
everything Maven is up to date, project(s) is(are) clean and up to date, etc.
If your project is really hierarchical and subsumes additional projects, and
the Maven pom.xml files have been well set up, then this command will
suffice for all if executed from the main project root (acme-parent ):
~/dev/acme-parent $ mvn eclipse:eclipse
Import project(s) into Eclipse using
File -> Import... -> General
-> Existing Projects into Workspace -> Next -> Browse
Select the project (root project) and click OK . You should see one
or more projects; select them all and click Finish .
Errors
These will be of several sorts. First, the unimportant ones that stem from
the habits of whoever wrote the code. You'll need to go into Window
-> Preferences -> Java -> Compiler -> Errors/Warnings
and turn off (Ignore ) any errors or warnings you don't wish to
face. Alernatively, you could clean up the code itself.
Important errors and warnings
These are what are truly challenging to fix. They're what's covered in the
remaining steps of this section.
Before continuing, ensure you have no m2e (Eclipse-Maven integration)
plug-ins installed. The reason for this is because this particular solution
does not seek to use those. If you wish to build your project using Maven,
you can always do so via the command line. This solution seeks to fix
Eclipse build errors, a sampling of which I've encountered follow.
Fix errors in Eclipse like...
4bis
Because IntelliJ is so Maven-oriented, things that are caused by or incidental
to Maven usage appear to be problems I'm covering here. To fix the errors in
the illustration above, set the classpath variables in the Eclipse workspace as
shown in the illustration below (see, in particular, M2_REPO ):
4ter
Here's another error:
Project 'acme-client' is missing required source folder: '/home/russ/dev/acme-parent/acme-config/environments/hudson'
Build Path Problem
by doing this:
Right-click on the project experiencing the problem (in this case,
acme-client , choose Properties .
Click Java Build Path .
Click on Source tab.
Look for a source folder in the list that matches the name in the error;
this will likely be marked with "(missing)".
Select the line with "(missing)" on it and click Remove button.
(See illustration below.)
Click OK ; likely the Errors list will be shortened by
at least one line.
There is some obfuscation in this illustration because I'm protecting my
employer's source and reputation.
Fix missing symbol, method, etc. errors. This is where being crippled in
Maven integration has its effect. I found that by introducing Eclipse-Maven
integration plug-ins, I was only creating insurmountable headaches for
myself. (I tried this in the latest Eclipse Kepler release and also Indigo.)
I found that refreshing ~/.m2/repository has no effect on workspace
projects when they begin to require updated JARs coming from the Maven
repository, so compilation errors like missing symbols go unsolved. I've
tried bouncing Eclipse, tried installing m2e and more m2e stuff (some of
which Eclipse moans about), but I can't get it to see the new stuff in the
local repository.
What did work was rebuilding my workspace following the steps above. Of
course, this is not helpful. It might be that the affected project(s) need
special treatment. I will come back and post a solution to this as soon as
I find one. It's probably going to be simple.
Stuff to try:
Bounce workbench—didn't work.
Do Maven build on command line.
Do build using IntelliJ (in parallel).
