Adding and Testing Java Classes in a new Gradle Project

Creating a new Gradle Project

Open Project Wizard, in the left-hand pane select Gradle.
In the right-hand pane, IntelliJ IDEA automatically adds a project SDK (JDK) and a default option Java in the Additional Libraries and Frameworks area. You can edit this information if you like.
Click Next.
On the next page of the wizard let's specify ArtifactId which basically the name of our project. We can use the default information in the version field. Unless we plan to deploy our project in some Maven repository we don't need to specify a GroupId.
Click Next.
On the next page of the wizard, let's leave the default options such as Create separate module per source set and Use default gradle wrapper (recommended) selected. We will specify two more options:
- Use auto-import - to resolve all the changes made to the Gradle project automatically every time we refresh our project.
- Create directories for empty content roots automatically - to create the default directory structure for our Gradle project, e.g. /src/main/java and /src/test/java.
Click Next.
We've already specified our project's name, let's specify the location of our project and click Finish.

IntelliJ IDEA creates a project with build.gradle file and src folder with main and test subdirectories.

/help/img/idea/2017.1/gradle_project_view.png

IntelliJ IDEA also creates a dedicated tool tool window with default tasks.

/help/img/idea/2017.1/gradle_tool_window.png

For more information on creating a Gradle project with the options that are out of this scope, see Gradle.

Adding Java and test classes to a Gradle project

Let's add Java and test classes to our Gradle project.

Note that if you didn't select the Create directories for empty content roots automatically option while creating a project you can select this option on the Gradle page in the Settings dialog (Ctrl+Alt+S). So IntelliJ IDEA can add the src directory to the project.

/help/img/idea/2017.1/gradle_page_project_settings.png

In the project view open the src folder.
Right-click on the main or test directory then on the java subdirectory and from the list that opens select New | Java Class.
In the Create New Class dialog specify the name of your Java or test class and click OK.

Let's add the following code:

for our HelloWorld class -
for our Test class -

Running tests in a Gradle project

We can run our test in several different ways:

using the editor - click in the left gutter of the editor.
using the Gradle task test - in the Gradle tool window open Tasks directory and then verification subdirectory. In the list that opens, double-click test to run your test.
using the Delegate all IDE builds/run actions to gradle option in the Settings dialog.