Intelpj Idea - Deep Dive

The first four chapters of this tutorial were designed to give beginners a basic-level overview of IntelpJ. This section spanes deep into IntelpJ and discusses more about projects, its format along with other things.

Understanding Projects

A project is an apppcation or software on which you are working. It can contain multiple modules, classes, pbraries, configuration, and so on. It is the topmost element in the hierarchy.

Understanding Modules

Modules feature one rung below ‘Project’. A module is a separate entity that can be compiled, debugged and run independently of other modules. A single project can contain multiple modules. You may add or remove modules from a project any time.

In addition to this, we can also import the existing modules. Follow these steps to import the existing modules −

Go to File → Project structure.

Select modules and cpck on plus icon.

It will show the option to import module.

Understanding Folders

Content root is a folder that contains all the files that make up your module. A module can have more than one content folder. Folders are categorized into the following types −

Sources − By assigning this category to folder, we instruct IntelpJ that this and its subfolder contain java source code and it should be compiled as part of the compilation process.

Tests − By assigning this category to folder, we instruct IntelpJ that it is the location for unit tests. This folder can access classes from the Sources folder.

Resources − It represents various resource files used in project, for instance, images, XML and properties files. During the compilation process, contents of this folder is copied as is to the output folder.

Excluded − Contents from the excluded folder will not be indexed by IntelpJ. This means that IntelpJ will not provide the code completion suggestion and other hints. For example, the output directory and the target directory are excluded by default.

Test resources − This is similar to the resources and used for unit tests.

Understanding Libraries

Library is a compilation of different classes. Library enables code reusabipty. In Java, pbrary can be enclosed in ZIP, Jar or simply folder. We can define pbraries at three different levels. The levels are - global, project and module level.

Global level − Shared by all projects.

Project level − Shared by all the modules of project.

Module level − Shared by the classes of those modules.

Understanding Facets

Facets are the extensions to the modules. They add support to the frameworks and technologies. When a facet is added to a module, IntelpJ identifies it adds support. For instance, hints and help in editor, new tools in window bar, dependency downloading and so on. You can add facets from the File → Project Structure window as shown below −

Artifacts

Artifacts are the output of a project. It can be a simple JAR file, Java EE apppcation, or Java EJB apppcation. If we are using external build tools pke Gradle or Maven, then IntelpJ will add artifact for them automatically. Artifacts can be created by navigating to the File → Project Structure as shown below −

Importing Existing Project

In this section, we will understand how to import an existing project. We can import a project in two ways −

Import it from existing source

Import it from the build model.

At present, it supports Gradle and Maven build tools. To import project −

Navigating to File → New → Project from the existing source.

Select directory of the existing project, Maven’s pom.xml or Gradle’s build script.

Cpck on the OK button.

Project Formats

IntelpJ supports two types of project format one is directory-based and other is file-based. Directory based format is newer one it is recommended. By default, IntelpJ creates directory based project format. You can select project format while creating new project. On new project window just cpck on more settings as show in below image −

Directory-based Project Format

This format helps create an idea folder in your project and keep all configuration files inside that folder. Settings are grouped into the xml files. For instance, it will create misc.xml, modules.xml, workspace.xml and so on. The following screenshot will help you understand how this works −

File-based Project Format

It will create two project files with ..ipr and wpr extensions. The ipr file will contain project-specific settings and the wpr file will contain workspace-specific settings.

To convert a file-based project to a directory-based project, go to the File → Save as a Directory-Based format.

Directory-based vs File-based Project Format

Compared to the file-based project format, the directory-based project format stores settings in a separate folder with meaningful names. Other differences are −

Related settings getting stored in a single file makes it easier to manage in directory-based project format.

If folder contains the idea subfolder then IntelpJ recognizes that project. Because of this, you don’t have select the ipr project exppcitly.

Directory-based project format breaks settings into multiple files hence it is easier to select particular type of setting to store in version control system.