Developing a Java EE application
This tutorial illustrates the Java EE application development workflow.
The application that we will develop will be a minimal one. It'll be a one JSP page Java web application. However, the IntelliJ IDEA features discussed here are applicable to Java EE applications of any complexity.
- Before you start
- Creating a project
- Exploring the project structure
- Developing source code
- Running the application
- Modifying the code and observing the changes
- Exploring a run configuration. Fixing debug settings
- Exploring an artifact configuration
- Packaging the application into a WAR file
Before you start
Make sure that the following software is installed on your computer:
- IntelliJ IDEA ULTIMATE Edition.
- Java SE Development Kit (JDK), version 6 or later. Download Oracle JDK.
- GlassFish Server, version 3.0.1 or later. Download GlassFish. (You can use any other Java EE-enabled application server. GlassFish is used here just as an example.)
- A web browser.
Creating a project
Click Create New Project on the Welcome screen, or
select File | New | Project.
The New Project wizard opens.
- In the left-hand pane, select Java Enterprise.
If the JDK that you want to use is already defined in IntelliJ IDEA,
select that JDK from the Project SDK list and
proceed to the
Otherwise, click New, select JDK, and select the JDK installation folder in the dialog that opens.
Specify the application server that you are going to use.
(We'll use GlassFish Server.)
If GlassFish is not defined in IntelliJ IDEA yet, click New to the right of the Application Server field and select Glassfish Server.
In the Glassfish Server dialog, specify the GlassFish Server installation directory.
Under Additional Libraries and Frameworks,
select the Web Application check box.
Specify the name for your new project (e.g.
Click Finish and wait while IntelliJ IDEA is creating the project.
Exploring the project structure
When the project is created, you'll see something similar to this in the Project tool window.
JavaEEHelloWorld is a module folder
(which in this case coincides with the project folder).
.ideafolder and the file
JavaEEHelloWorld.imlcontain configuration data for your project and module respectively. The folder
srcis for your Java source code. The folder
webis for the web part of your application. At the moment this folder contains the deployment descriptor
WEB-INF\web.xmland the file
index.jspintended as a starting page of your application.
- External Libraries include your JDK and the JAR files for working with GlassFish.
Developing source code
Our application will be a single JSP page application. Its only function will be to output the text Hello World!
index.jspfor editing: select the file in the Project tool window and press F4.
The code at this step is ready.
Running the application
In the upper-right part of the workspace, click .
IntelliJ IDEA compiles your source code and builds an application artifact. (We'll discuss artifacts a bit later. For now, the artifact is your application in deployment-ready format.)
After that, the Run tool window opens. IntelliJ IDEA starts the server and deploys the artifact onto it.
Finally, your default web browser starts and
you see the application output
Hello World! there.
Modifying the code and observing the changes
- In the Run tool window, click the Update icon .
- In the Update dialog, select Update resources and click OK. (For more information, see Application update options.)
- Switch to the web browser and reload the page to see the changes.
See also, Updating Applications on Application Servers.
Exploring a run configuration. Fixing debug settings
When creating the project, we specified GlassFish as an application server. As a result, IntelliJ IDEA created a run configuration for GlassFish.
When we performed the Run command (), we started that run configuration. Now let's take a look at the run configuration and see how its settings map onto the events that we've just observed.
Click the run configuration selector and select Edit Configurations.
The Run/Debug Configurations dialog opens and the settings for the GlassFish run configuration are shown.
The Before launch task list (in the lower part of the dialog) specifies that the application code should be compiled and the corresponding artifact should be built prior to executing the run configuration.
- Select the Startup/Connection tab to see how the server is started in the run, debug and code coverage modes.
- Select the Deployment tab to see which artifacts are deployed after the server is started.
Go back to the Server tab.
The settings under Open browser specify that after launch (i.e. after the server is started and the artifacts are deployed onto it) the default web browser should start and go to the specified URL (
The settings to the right of On 'Update' action specify that on clicking in the Run tool window the Update dialog should be shown and the Update resources option should be used by default. (The last used update option becomes the default one).
Note the warning Debug settings are invalid in the lower part of the dialog.
(IntelliJ IDEA makes the necessary changes to GlassFish
- Click OK.
Exploring an artifact configuration
The word artifact in IntelliJ IDEA may mean one of the following: 1) an artifact configuration, i.e. a specification of the output to be generated for a project; 2) an actual output generated according to such a specification (configuration).
When creating the project, we indicated that we were going to develop a web application. As a result, IntelliJ IDEA, among other things, created a configuration for building a web application. Let's have a look at this configuration.
- Open the Project Structure dialog: File | Project Structure or Ctrl+Shift+Alt+S.
Under Project Settings, select Artifacts.
The available artifact configurations are shown in the pane to the right under and . (There's only one configuration at the moment.)
The artifact settings are shown in the right-hand part of the dialog.
Type. The artifact type is Web Application: Exploded. This is a decompressed web application archive (WAR), a directory structure that is ready for deployment onto a web server.
Output directory. The artifact, when built, is placed into
Output Layout. The artifact structure is shown in the left-hand pane of the Output Layout tab.
The <output root> corresponds to the output directory. Other elements have the following meanings:
'JavaEEHelloWorld' compile output represents
compiled Java classes whose sources are located in the
srcdirectory. These are placed into
WEB-INF\classesin the output directory.
'Web' facet resources represent the contents of
- 'JavaEEHelloWorld' compile output represents compiled Java classes whose sources are located in the
Packaging the application into a WAR file
When you get to the stage when you are happy with your application, you may want to place it in a WAR (web application archive). To do that, you should create an appropriate artifact configuration and then build the artifact:
Click , point to Web Application: Archive and
select For 'JavaEEHelloWorld: war exploded'.
A new artifact configuration is created and its settings are shown in the right-hand part of the dialog.
If necessary, create a manifest file for your archive:
click Create Manifest and
agree to the location suggested by IntelliJ IDEA (
- Click OK in the Project Structure dialog.
- Select Build | Build Artifacts.
In the Build Artifact popup,
point to JavaEEHelloWorld:war and
Now if you look at the
out\artifacts\JavaEEHelloWorld_warfolder in the Project tool window, you'll see the archive there.