Intellij cannot find any declarations

java

intellij-configuration

project-structure

java-sdk

byAlex Kataev·Feb 24, 2025

If you're bumping into declaration issues, give these steps a shot:

Invalidate Caches / Restart... > Invalidate and Restart from File menu to reset and re-index your project.
Ensure the Project SDK is set. Visit the Project Structure (Ctrl+Alt+Shift+S) for the SDK settings.
Review your build tool configuration (Maven/Gradle) to ensure dependencies are accounted for.

// Quick fix action: Invalidate caches
File > Invalidate Caches / Restart... > Invalidate and Restart
// IntelliJ couldn't find my declarations, so we had to part ways...temporarily. 😉

Source Root Verification

In instances where IntelliJ can't seem to locate your src folder, you may need to flag it as the Sources Root:

Right-click the src folder.
Choose Mark Directory as > Sources Root.

Properly marking your source folder helps IntelliJ index your project correctly, eliminating the "cannot find declaration" error.

House Cleaning: Delete User Files

Sometimes, IntelliJ's configurations can misbehave. When that happens, perform the following steps:

Exit IntelliJ IDEA to avoid conflicting processes.
Navigate to your project directory and delete the .idea folder and .iml files.
Clear system caches nested under your user home directory, specifically in .IntelliJIdea<version>, .idea, caches, and index.

Afterward, launch IntelliJ again and re-import your project. It's like giving IntelliJ a fresh new haircut, but for your project configuration files.

Java SDK Checks

For a smooth IntelliJ operation, valid Java SDK is a must-have:

Go to File > Project Structure... > Platform Settings > SDKs.
Verify that the SDK path is correctly set, without any warning symbols. Your Java SDK is your project's fuel, ensure it's pure.

Maven and Gradle Handlings

Manage dependencies in Maven projects via the pom.xml:

Right-click pom.xml
Click on Add as Maven Project

In Gradle situations:

Click on the Refresh icon on the Gradle panel
Re-import the project if required.

Before you proceed, let IntelliJ finalize caching to avoid half-baked operations.

Clear Project Setup

A brief checklist to avoid navigation issues:

Verify that IntelliJ recognizes your project structure appropriately.
Be patient and allow IntelliJ time to index and rebuild caches after each clean or reset operation.
Delete .idea workspace configuration and .iml module files to reset IntelliJ-specific settings.