I have heard from people who have switched either way and who swear by the one or the other.
Being a huge Eclipse fan but having not had the time to try out IntelliJ, I am interested in hearing from IntelliJ users who are "ex-Eclipsians" some specific things that you can do with IntelliJ that you can not do with Eclipse.
Note: This is not a subjective question nor at all meant to turn into an IDE holy war. Please downvote any flamebait answers.
CTRL-click that brings you to where clicked object is defined works everywhere - not only in Java classes and variables in Java code, but in Spring configuration (you can click on class name, or property, or bean name), in Hibernate (you can click on property name or class, or included resource), you can navigate within one click from Java class to where it is used as Spring or Hibernate bean; clicking on included JSP or JSTL tag also works, ctrl-click on JavaScript variable or function brings you to the place it is defined or shows a menu if there are more than one place, including other .js files and JS code in HTML or JSP files.
Autocomplete in HSQL expressions, in Hibernate configuration (including class, property and DB column names), in Spring configuration
<property name="propName" ref="<hit CTRL-SPACE>"
and it will show you list of those beans which you can inject into that property.
Very smart autocomplete in Java code:
interface Person {
String getName();
String getAddress();
int getAge();
}
//---
Person p;
String name = p.<CTRL-SHIFT-SPACE>
and it shows you ONLY getName(), getAddress() and toString() (only they are compatible by type) and getName() is first in the list because it has more relevant name. Latest version 8 which is still in EAP has even more smart autocomplete.
interface Country{
}
interface Address {
String getStreetAddress();
String getZipCode();
Country getCountry();
}
interface Person {
String getName();
Address getAddress();
int getAge();
}
//---
Person p;
Country c = p.<CTRL-SHIFT-SPACE>
and it will silently autocomplete it to
Country c = p.getAddress().getCountry();
Smart autocomplete in JavaScript.
function Person(name,address) {
this.getName = function() { return name };
this.getAddress = function() { return address };
}
Person.prototype.hello = function() {
return "I'm " + this.getName() + " from " + this.get<CTRL-SPACE>;
}
and it shows ONLY getName() and getAddress(), no matter how may get* methods you have in other JS objects in your project, and ctrl-click on this.getName() brings you to where this one is defined, even if there are some other getName() functions in your project.
Did I mention autocomplete and ctrl-clicking in paths to files, like <script src="", <img src="", etc?
Autocomplete in HTML tag attributes. Autocomplete in style attribute of HTML tags, both attribute names and values. Autocomplete in class attributes as well.
Type <div class="<CTRL-SPACE> and it will show you list of CSS classes defined in your project. Pick one, ctrl-click on it and you will be redirected to where it is defined.
Latest version has language injection, so you can declare that you custom JSTL tag usually contains JavaScript and it will highlight JavaScript inside it.
<ui:obfuscateJavaScript>function something(){...}</ui:obfuscateJavaScript>
You can use Find Usages of any Java class or method and it will find where it is used including not only Java classes but Hibernate, Spring, JSP and other places. Rename Method refactoring renames method not only in Java classes but anywhere including comments (it can not be sure if string in comments is really method name so it will ask). And it will find only your method even if there are methods of another class with same name. Good source control integration (does SVN support changelists? IDEA support them for every source control), ability to create a patch with your changes so you can send your changes to other team member without committing them.
When I look at HashMap in debugger's watch window, I see logical view - keys and values, last time I did it in Eclipse it was showing entries with hash and next fields - I'm not really debugging HashMap, I just want to look at it contents.
It validates Spring and Hibernate configuration right when you edit it, so I do not need to restart server to know that I misspelled class name, or added constructor parameter so my Spring cfg is invalid.
Last time I tried, I could not run Eclipse on Windows XP x64.
and it will suggest you person.name or person.address. Ctrl-click on person.name and it will navigate you to getName() method of Person class.
Type Pattern.compile(""); put \\ there, hit CTRL-SPACE and see helpful hint about what you can put into your regular expression. You can also use language injection here - define your own method that takes string parameter, declare in IntelliLang options dialog that your parameter is regular expression - and it will give you autocomplete there as well. Needless to say it highlights incorrect regular expressions.
There are few features which I'm not sure are present in Eclipse or not. But at least each member of our team who uses Eclipse, also uses some merging tool to merge local changes with changes from source control, usually WinMerge. I never need it - merging in IDEA is enough for me. By 3 clicks I can see list of file versions in source control, by 3 more clicks I can compare previous versions, or previous and current one and possibly merge.
It allows to to specify that I need all .jars inside WEB-INF\lib folder, without picking each file separately, so when someone commits new .jar into that folder it picks it up automatically.
Mentioned above is probably 10% of what it does. I do not use Maven, Flex, Swing, EJB and a lot of other stuff, so I can not tell how it helps with them. But it does.
There is only one reason I use intellij and not eclipse: Usability
Whether it is debugging, refactoring, auto-completion.. Intellij is much easier to use with consistent key bindings, options available where you look for them etc. Feature-wise, it will be tough for intellij to catch up with Eclipse, as the latter has much more plugins available that intellij, and is easily extensible.
Probably is not a matter of what can/can't be done, but how.
For instance both have editor surrounded with dock panels for project, classpath, output, structure etc. But in Idea when I start to type all these collapse automatically let me focus on the code it self; In eclipse all these panels keep open leaving my editor area very reduced, about 1/5 of the total viewable area. So I have to grab the mouse and click to minimize in those panels. Doing this all day long is a very frustrating experience in eclipse.
The exact opposite thing happens with the view output window. In Idea running a program brings the output window/panel to see the output of the program even if it was perviously minimized. In eclipse I have to grab my mouse again and look for the output tab and click it to view my program output, because the output window/panel is just another one, like all the rest of the windows, but in Idea it is treated in a special way: "If the user want to run his program, is very likely he wants to see the output of that program!" It seems so natural when I write it, but eclipse fails in this basic user interface concept.
Probably there's a shortcut for this in eclipse ( autohide output window while editing and autoshow it when running the program ) , but as some other tens of features the shortcut must be hunted in forums, online help etc while in Idea is a little bit more "natural".
This can be repeated for almost all the features both have, autocomplete, word wrap, quick documentation view, everything. I think the user experience is far more pleasant in Idea than in eclipse. Then the motto comes true "Develop with pleasure"
Eclipse handles faster larger projects ( +300 jars and +4000 classes ) and I think IntelliJ Idea 8 is working on this.
All this of course is subjective. How can we measure user experience?
Idea 8.0 has the lovely ctrl+shift+space x 2 that does the following autocomplete:
City city = customer.<ctrl-shift-space twice>
resolves to
City city = customer.getAddress().getCity();
through any number of levels of getters/setters.
Don't forget "compare with clipboard".
Something that I use all the time in IntelliJ and which has no equivalent in Eclipse.
My favorite shortcut in IntelliJ that has no equivalent in Eclipse (that I've found) is called 'Go to symbol'. CTRL-ALT-SHIFT-N lets you start typing and glob up classes, method names, variable names, etc, from the entire project.
If you have the cursor on a method then CTRL+SHIFT+I will popup the method implementation. If the method is an interface method, then you can use up- and down- arrows to cycle through the implementations:
Map<String, Integer> m = ...
m.contains|Key("Wibble");
Where | is (for example) where your cursor is.
IntelliJ has some pretty advanced code inspections (comparable but different to FindBugs).
Although I seriously miss a FindBugs plugin when using IntelliJ (The Eclipse/FindBugs integration is pretty cool).
Here is an official list of CodeInspections supported by IntelliJ
EDIT: Finally, there is a findbugs-plugin for IntelliJ. It is still a bit beta but the combination of Code Inspections and FindBugs is just awesome!
One thing I use regularly is setting a breakpoint, but then controlling what it does. (At my last job, most everyone else used Eclipse... I remember being surprised that no one could find how to do this in Eclipse.)
For example, can have the breakpoint not actually stop, but just log a message to the console. Which means, I don't have to litter my code with "System.out.println(...)" and then recompile.
Structural search and replace.
For example, search for something like:
System.out.println($string$ + $expr$);
Where $string$ is a literal, and $expr$ is an expression of type my.package.and.Class, and then replace with:
$expr$.inspect($string$);
The IntelliJ debugger has a very handy feature called "Evaluate Expression", that is by far better than eclipses pendant. It has full code-completion and i concider it to be generally "more useful".
Well, for me it's a thousand tiny things. Some of the macros, the GUI layout in general in Eclipse I find awful. I can't open multiple projects in different windows in Eclipse. I can open multiple projects, but then it's view based system swaps a bunch of things around on me when I switch files. IntelliJ's code inspections seem better. Its popup helpers to fix common issues is nice. Lots of simple usability things like the side bar where I can hover over a hot spot and it'll tell me every implementing subclass of a method or the method I'm implementing and from where.
Whenever I've had to use, or watch someone use, Eclipse it seems like they can do most of the things I can do in IntelliJ, but it takes them longer and it's clunkier.
Introduce variable. (Ctrl+Alt+V on Windows, Cmd+Alt+V on OSX)
Lets say you call a method, service.listAllPersons()
Hit Ctrl+Alt+V and Enter, and variable for return value from method call is inserted:
List<Person> list = service.listAllPersons();
Saves you typing, and you don't have to check the return type of the method you are calling. Especially useful when using generics, e.g.
new ArrayList<String>()
[introduce variable]
ArrayList<String> stringArrayList = new ArrayList<String>();
(of course you can easily change the name of the variable before hitting Enter)
Intellij has a far superior SVN plug-in than either Subversive or Subclipse and it works! The amount of time we've wasted merging source files using Eclipse doesn't bear thinking about. This isn't an issue with IntelliJ because the plugin helps you much more.
Also the Subclipse plugin is unreliable - we regularly have instances where the plugin doesn't think there has been any code checked in to SVN by other developers, but there has - the CI server has processed them!
One of the good points in my opinion is the Dependency Structure Matrix: http://www.jetbrains.com/idea/features/dependency_analysis.html#link0
There's a good introduction to DSM usage and benefits in Lattix' website (a standalone product): http://www.lattix.com/files/dl/slides/s.php?directory=4tour
A few other things:
Two things that IntelliJ does that Eclipse doesn't that are very valuable to me:
Method separators: those faint gray lines between methods make code much more readable
Text anti-aliasing: makes code look so nice in the IDE
One very useful feature is the ability to partially build a Maven reactor project so that only the parts you need are included.
To make this a little clearer, consider the case of a collection of WAR files with a lot of common resources (e.g. JavaScript, Spring config files etc) being shared between them using the overlay technique. If you are working on some web page (running in Jetty) and want to change some of the overlay code that is held in a separate module then you'd normally expect to have to stop Jetty, run the Maven build, start Jetty again and continue. This is the case with Eclipse and just about every other IDE I've worked with. Not so in IntelliJ. Using the project settings you can define which facet of which module you would like to be included in a background build. Consequently you end up with a process that appears seamless. You make a change to pretty much any code in the project and instantly it is available after you refresh the browser.
Very neat, and very fast.
I couldn't imagine coding a front end in something like YUI backing onto DWR/SpringMVC without it.
Something which I use in IntelliJ all the time is refactoring as I type. I have re-written classes from a printout (originally written in eclipse) using both IDEs and I used about 40% less key strokes/mouse clicks to write the same classes in IntelliJ than eclipse.
I wouldn't want to use Eclipse until they support as much refactoring with incomplete pieces of code.
Here is a longer list of features in IntelliJ 8.0/8.1 [http://www.jetbrains.com/idea/features/index.html]
Preamble to my answer: My use of Eclipse is limited. We needed a Java IDE to work on both Windows and Mac and the Mac port slowed down day by day. This was years ago and I'm sure it's OK now. But that is what got us to switch to IntelliJ and we've been happy with it.
Now for my answer: One big difference I haven't seen mentioned yet is that tech support is better with IntelliJ/Jet Brains. We send an e-mail to JetBrains and get a definitive answer back in less than an hour. Looking for answers to Eclipse problems results in the usual, "You stupid idiot" answers (usually a small number of the replies) along with the much larger number of insightful, helpful replies. But it takes some sorting through to get the real answer.
I don't remember if word/line/method/class wrap is possible in Eclipse
In Intellij Idea you use Ctrl+W
Open a project from a Maven POM. Just select "Open project..." navigate to your top level pom.xml and hit Enter :) NetBeans now has this feature as well.
I not have coded a lot with IntellijIdea, but in IntellijIdea you can see where a block of code between brackets (if, try/catch, cycle, etc) begins and where finish.
In Eclipse (I code in Eclipse 3.2) you can identify the block only manually.