What are these folders and files in Java Project in IntelliJ IDEA?

1. .idea/

• Purpose: Stores IntelliJ-specific project settings.
• Contents: Configuration files for project structure, run configurations, code style, version control settings, etc.
• Note: Usually added to .gitignore because it's IDE-specific and not needed in source control.

2. .mvn/

• Purpose: Contains configuration for the Maven Wrapper.
• Contents: wrapper/ directory with files like maven-wrapper.jar and maven-wrapper.properties.
• Note: Ensures consistent Maven version across all developers without requiring Maven to be installed system-wide.

3. resources/

• Purpose: Holds non-Java files used by the app.
• Typical contents: .fxml files (for JavaFX), images, properties files, etc.
• Special: Anything here gets copied to target/classes/ during build, and is available on the classpath.
• e.g.: resources/org.group.demo/hello.fxml
  • Purpose: Example FXML file defining a JavaFX UI layout.
  • Location: Subfolder matches your package name (org.group.demo).
  • Usage: Loaded by FXMLLoader in your controller code.

4. target/

• Purpose: Build output directory generated by Maven.
• Contents: Compiled .class files, packaged .jar or .war, reports, etc.
• Note: Should not be committed to version control.

5. mvnw and mvnw.cmd

• Purpose: Maven Wrapper scripts.
• mvnw: For Linux/macOS
• mvnw.cmd: For Windows.
• Usage: Run /.mvnw instead of requiring users to install Maven.

6. pom.xml

• Purpose: The heart of a Maven project.
• Contains: Project metadata, dependencies, build configuration, plugins, etc.
• Note: This is where you add JavaFX or other dependencies.

7. External Libraries (in IntelliJ)

• Purpose: Not a folder, but a visual representation.
• What it shows:
  • Java SDK
  • Maven dependencies
  • JavaFX libraries (if configured)
• Helps: You see what external code your project depends on.