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Projects are the central concept of developing in IntelliJ IDEA. Let's explore how to create them and navigate around.
Note
The user interface for IntelliJ IDEA has changed since the filming of this video and the process for creating a new project is slightly different. Please refer to the Create Your First Project in IntelliJ IDEA instruction page for updated steps for creating a new project.
Code
package com.teamtreehouse;
import java.util.Set;
import java.util.TreeSet;
public class Systemizer {
public static void main(String[] args) {
System.out.printf("This is the classpath: %s %n",
System.getProperty("java.class.path"));
Set<String> propNames = new TreeSet<String>(System.getProperties().stringPropertyNames());
for (String propertyName : propNames) {
System.out.printf("%s is %s %n",
propertyName,
System.getProperty(propertyName));
}
}
}
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All right, we got our IDE installed and
we're ready to start our first project.
0:00
Projects can be thought of as what we
were exploring each time we created a new
0:04
work space.
0:07
So for instance we would have started a
new project for our Pez dispenser, one for
0:09
our hangman game or one for
our karaoke machine and
0:12
what ever else we end up
creating in the future.
0:15
So let's dive in and explore how to
create projects in your new environment.
0:18
All right, so if it's not started up
already, go ahead and start up IntelliJ.
0:23
Then we'll click this Create New Project.
0:27
Here you'll see it's asking for
a Project SDK.
0:29
Now SDK remember stands for
software development kit.
0:34
So let's choose the JDK we installed.
0:37
Oh, it's not here, that's just common
the first time you start up IntelliJ,
0:40
the very first time.
0:44
After we do this we won't
need to do it again.
0:45
So, I'm gonna click new over here and
0:47
you'll see there's different types
of SDK's that are available, and
0:49
the one that we want is the JDK,
or the java development kit.
0:52
I'm gonna click that and of course this
is gonna look different if you're on
0:56
a different OS It's gonna try
to guess where it's at and
0:59
this on a Mac here will show what
the directory structure looks like.
1:03
So here we go, yeah this looks right
it's in the library it's the JAVA.
1:07
The one that I installed was JDK1.8.
1:09
You might have installed a later version,
okay, great.
1:12
So I'm gonna go head and
I'm just gonna click choose.
1:18
Because it was correct, and
there, sure enough there it is.
1:20
So now we have this project SDK here,
cool.
1:23
So let's click next.
1:26
All right, so
in this oddly laid out window here,
1:28
it's asking us if we wanna create
a new project from a template.
1:31
Now templates help by
creating common code for us.
1:35
For instance, the one template that
we have available here is called
1:37
the command line application.
1:41
Also known as the console applications
that we've been building.
1:43
So, what this will do is it will write
the boilerplate Java main method, and
1:46
let's go ahead and do that.
1:51
Let's choose that.
1:51
So, I'm gonna click this, and it
automatically chose that, and it says down
1:52
here, Simple Java application that
includes a class with the main method.
1:55
That's exactly what we want.
1:58
Great, so, let's choose that.
1:59
We'll click Next.
2:01
Okay, so let's name our project.
2:03
For this first one let's just recreate
that systemizer class that we wrote in
2:04
the work space earlier.
2:08
So, the name of this project
would be Systemizer, cool.
2:09
And see how it normally, it started
going ahead and typing along and
2:15
naming the folder the same as the project.
2:18
That'll help us find it later so
very similar on a Mac,
2:20
this is my home directory, and then
there's a folder called IdeaProjects.
2:23
And whatever I named
that is what it put here.
2:27
I could make this different, but that's
what I wanna have, I'm gonna leave it.
2:29
And the base package, remember this
is packages like we have been doing.
2:32
So, you take your URL and flip it around.
2:35
So we're com.teamtreehouse,
if you have a website and
2:38
you feel like putting it in there,
feel free to do so.
2:42
I'm gonna go ahead and click Finish and
that's gonna build everything out for us.
2:44
Okay, so these tips here, these are pretty
awesome, but they're a little overwhelming
2:50
and in your face, especially when
you're just getting started.
2:54
So what I'm gonna do is I'm gonna leave
this check box, Show Tips on Startup,
2:56
checked, but
I'm gonna go ahead and close them.
2:59
This is a great place to go,
and you can click Next Tip and
3:01
Previous Tip and kinda walk through and
learn things about your IDE here.
3:04
So I'm gonna go ahead and
close it for now though.
3:08
So before we get started I just wanted
to let you know that I have a plugin
3:10
installed that will show key
commands as I'm using them,
3:13
like keyboard shortcuts that I'm doing.
3:15
And it will show both Mac and Windows.
3:18
Now, the keyboards on Mac and
Windows machines,
3:20
if you don't know,
are a little bit different and
3:23
therefore the hotkeys that you do to
do things are a little bit different.
3:25
I just thought it'd be nice to show
on the screen what's going on.
3:28
You will not see those on your
screen don't worry about that.
3:31
So this area here is called the editor and
it's where we're going to do editing and
3:35
it works much like that editor
we were using in workspace, but
3:38
it is infinitely more powerful.
3:42
Now since Java's a strongly type language,
it knows things about what we're trying to
3:45
do, through a process
called code inspection.
3:49
Here, check this out.
3:52
I'm gonna start typing, and it's going to
take a stab about what I'm talking about.
3:52
This is called code completion.
3:57
So, I'm gonna type S, and look at that.
3:58
It popped up a list of what I
could probably be talking about.
4:01
So, I'm going to use the arrow keys and
I'm going to choose System,
4:04
because what I want to do here is I'm
going to write out to the screen.
4:08
Let's do System.out.println.
4:10
So, I'm gonna choose System, I moved using
the arrow keys and I'm gonna press dot.
4:12
And there it chose that and because
it knows what type of class this is,
4:18
it knows what the public fields are and
it also knows what all the methods are.
4:22
So you can see all the methods
that are available here.
4:26
So I'm gonna go ahead and choose out and
again I'm gonna press dot.
4:28
And because it knows what type out it is
it knows the different things that it
4:32
can do so, if we stroll down here we can
see that it has print, I can start typing
4:36
as well and it will go down on the list of
what's available and I wanna do println.
4:40
So that's great let's go ahead and
backup a bit I just want
4:45
to show you what would happen if we move
away so I'm gonna click my mouse away.
4:47
Now you'll see that it
highlighted in red and
4:51
see that little red squiggly line here?
4:53
Let's mouse over that and it says,
that it can not resolve symbol 'pr'.
4:54
And that also there's another error,
that it expected a semi colon.
5:00
Handy, right?
5:05
So I'm gonna to go back and
put my cursor right here and
5:06
if I wanted to get the code completion to
kick off again, I can press control space.
5:08
Give that a second.
5:14
The first time that this kicks
off it has to index everything.
5:15
So just give this one second and
it'll be quicker in a bit.
5:18
Again so we can choose println and
we'll say hello from our IDE.
5:21
Cool so I'm gonna go ahead and
save and I did that with Apple S and
5:29
because that's such
a common thing to do right.
5:35
If you're going to always be logging out
to the screen, there's a shortcut to it.
5:37
So if you type out S-O-U-T and actually
see there's some other ones on here.
5:42
But we're going to to S-O-U-T and
I'm going to press the tab key and
5:47
there's the System.out.println.
5:51
There, lots of savings there.
5:52
Okay so let's just go ahead and run this.
5:59
Now remember what we had to do in the past
was compile with the Java C program and
6:03
then run the program
with the Java command.
6:07
Well guess what,
this IDE knows how to do that.
6:09
To run this code let's go to the Run menu,
it's up here Run and chose run main.
6:12
Note next to this instruction here
there's a little keyboard shortcut here.
6:20
So it's saying on a Mac if
I do Ctrl + R it will run.
6:24
Now because we created this project
using the command line template
6:27
everything was already all set up for
us to just run this.
6:31
We'll see later how to
configure things this way but
6:34
because the template was using main it
automatically knows what that is so
6:36
let's go ahead and let's run this.
6:39
Okay so now things are being compiled and
6:41
it ran and here in this area
down here is our console.
6:46
If you mouse over you can see
the program that was actually run and
6:50
you can see here that it says JAVA and
6:53
then a bunch of parameters dropped
we'll explore that a little bit later.
6:55
So, you can see how the program ran.
6:59
I clicked in and I'm just going to
move my mouse, move my cursor over and
7:03
we could see that I called all
of these different properties.
7:08
Wow, right, and there it's at the class
path that was in the dash CP we did
7:11
before, so it got the class path also,
so I just wanted to show you that and
7:15
that's how it's running it off.
7:20
And here's our messages,
hello from our IDE and saving space.
7:21
Those are just the two
things that I wrote there.
7:23
Okay, so, let's go ahead,
I'm going to remove these two lines and
7:25
save again.
7:30
Okay, so let's go grab the code
that we wrote in workspace and
7:34
just plop in in here.
7:37
It's in the teacher's notes below.
7:38
So, I came over to my workspace and
I copied and I'm gonna come in here and
7:40
I'm just gonna paste.
7:44
All right, so
let's move the cursor over here where
7:48
it's highlighted in red,
this thing set here.
7:53
Let's see what it says.
7:58
It's saying that it doesn't
know what a set is, and
8:00
I remember we didn't import that.
8:02
So that's why it's saying that.
8:04
So let's go ahead, I'm gonna press, and
8:05
that key command there is Alt + Enter on a
Mac that's what it's suggesting that I do.
8:08
So I'm gonna go ahead,
I'm gonna press that, okay.
8:12
And here is the action that it's
suggesting is to import the class, so
8:16
let's go ahead and do that, cool.
8:19
And then it's doing it again for
the TreeSet, so I'm gonna do that again.
8:22
I'm gonna press Alt+Enter, and
it imported and if we scroll up,
8:25
you'll see that it did the imports for
us, pretty cool, right?
8:28
Huh, it looks like there's
still a problem so,
8:32
look here I haven't let's mouse over here.
8:36
It says class or interface on this one.
8:38
I think I have an extra brace so if I move
my cursor, see how it highlights this ones
8:40
highlighted and
that ones highlighted up there.
8:45
And then if I go to this one
that's closing the main class
8:47
then this is closing nothing.
8:50
So I have an extra brace, so
I'm gonna go ahead and get rid of that,
8:52
and now everything is happy.
8:55
There we go, so I'm gonna save that.
8:56
All right, so let's run that again.
8:59
So again, that was Ctrl+R or
Shift+F10 on Windows and Linux.
9:02
Cool, awesome, here it is.
9:12
It's a whole of different things.
9:14
Okay so now one more thing that I
wanted to show you really quick.
9:16
Let's say that we were looking at this
code that we wrote just a while ago, but
9:19
let's say that we forgot
what some of this was.
9:22
So, if I wanted to highlight over this,
and
9:24
I wanted to see what this said,
I could just press F1 for help.
9:26
So here it is about the getProperties and
9:31
it says that it returns the
java.util.Properties and I can click that.
9:33
And I can navigate just like we
did to the documentation, but
9:36
here it is, right in our code.
9:38
Wow, right?
9:41
What a powerful set of tools all ready,
and there are so
9:43
many more packed in there.
9:45
I think a handy way to view
this might be as a tool shed.
9:47
There are lots of powerful tools in
the tool shed that assist you in making
9:51
tons of cool things.
9:54
But they aren't used all the time.
9:55
I mean you don't use the jigsaw
every time you build something.
9:58
Sometimes you just need a sander but
10:01
when you do need that jigsaw
it's good to know it's there.
10:03
And like I mentioned, well, not all tool
sheds have the same tools in them, more or
10:07
less, the same tools are available
in every heavily used tool shed.
10:12
Eventually, every tool
shed owner buys a nail gun
10:16
just to stay competitive with
their neighbors tool shed.
10:19
I'm going to do my best at walking you
through each of these different tools
10:22
in your IDE tool shed.
10:26
But I'm sure we won't touch on all of it.
10:27
Feel free to explore, you'll not only
learn about what the idea is capable of,
10:29
but also some great Java
best practices as well.
10:34
And unlike the tool shed
analogy I just used,
10:37
you don't have to worry about
losing a finger if you mess up.
10:39
The help system at IntelliJ
is really great and
10:42
I wanna show you how to explore around.
10:45
If you find some killer tool that you
just love, share it in the forum.
10:47
This stuff can be super exciting,
and let's not let it overwhelm us.
10:50
Sound good?
10:54
I wanna show you how to deal
with multiple files and
10:55
importing other projects,
right after this next exercise.
10:57
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