1.5. Your First Java Project¶

Following the “Hello, World” trend, let’s create a new IntelliJ project.

1. Create a new folder to hold your Java practice files. Since you will be creating lots of small projects as you move through this course, we suggest that you also add sub-folders with names corresponding to the related chapters and projects. Something like java-practice/chapter-name/project-name.

2. Select the New Project option from the welcome screen.

   

   Start a new project¶

3. Clicking New Project opens a window with a series of project settings to select. This window is called the new project wizard.

   1. Choose Java from the options on the left in the project wizard.
   2. For Project SDK, you’ll want to use version 11 that you have downloaded. If 11 is not already selected in the SDK window, click New on the right and find the JDK you have just downloaded.

   The SDK allows IntelliJ to compile our Java code when we launch our programs. Click Next in the lower right corner of the window to continue selecting settings.

   

   Select project SDK¶

4. In the second window, select Create project from template. This gives us some of the Java project scaffolding to save us some time with project infrastructure.

   

   Select project template¶

5. On the next window, enter HelloWorld for the name of the project. Click on the “3-dot” button to select a location to save the project. Here you can choose the Java projects folder you created in step one. You do not need to change the base package.

   

   Create the HelloWorld project in your Java projects folder.¶

6. Click Finish to create the project. Below is the view of your new project. Click on the item labelled Project with an icon that looks like a file folder on the left of the project window.

   

   Initial IntelliJ project view¶

   The section on the left is the project’s file tree.

   Clicking the triangle next to the project name, HelloWorld, displays the src file, followed by the base package we created, and finally our Main.java file.

   Main.java is also opened on the right in this initial project view.

   In line 1, package com.company, establishes a package, which Java uses to help organize and encapsulate our code.

7. We’ll dive into the use of a main function and Main class later. At this point, let’s just get right to printing our greeting. Where the project template tells you to write your code on line 6, add the following:

   System.out.println("Hello, world!");
   

   Ok sure, we haven’t gone over this exact syntax yet. But you can take a guess at what this line will do.

8. To run your program in IntelliJ, you have several options.

   

   IntelliJ run code options¶

   You can click on either of the green arrows indicated above, or choose Run from your top menu bar.

9. Once run, IntelliJ will generate a third panel in your view, with your program’s output:

   

   IntelliJ output¶

This is just the start of your relationship with IntelliJ. Now that we know the fundamentals, let’s return to Java basics so we can start writing more code.

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public class HelloWorld {

   public static void main(String[] args) {
      System.out.println("Hello, World");
   }

}