Why does IntelliJ give me "Package doesn't exist" error?

java

intellij

maven

gradle

byAlex Kataev·Nov 21, 2024

To tackle the "Package doesn't exist" error in IntelliJ, you can:

Purge cache: Go to File > Invalidate Caches / Restart….
Inspect module sources: Right-click module, go to Open Module Settings, verify sources setup.
Check for missing libraries: Visit Project Structure > Libraries, ensure you have the correct library setup.
Review build paths: In Project Structure > Modules, verify that the dependency scope and directory inclusion are correct.
Resync Maven/Gradle: Remember to reimport dependencies for consistency.

Next, make sure your Maven dependency is set like this:

<!-- Let's get the party started with the correct dependency block -->
<dependency>
    <groupId>your.groupid</groupId>
    <artifactId>your-artifactid</artifactId>
    <version>your.version</version>
</dependency>

Then use the magic Maven wand:

mvn idea:idea  # Boom! IntelliJ project files updated.

Lastly, confirm that your configurations align and then rebuild your project.

Advanced Jedi tricks

If "Package doesn't exist" error remains stubborn, it's time for some advanced tricks. IntelliJ indices sometimes need a good kick.

Removing .idea folder

This step is the Jedi mind trick of IntelliJ:

Exit IntelliJ.
Navigate to your project directory.
Vanish the .idea folder.
Reopen IntelliJ and commence a "Force reimport" of the project.

Rebuild and Reimport

Before any mind tricks, try the Jedi basics: rebuild the project (Build > Rebuild Project) and re-import Maven project (Right-click pom.xml > Reimport).

Validate Project SDK

Under Project Structure > Project, confirm that the JDK version is not playing hide-and-seek.

Maven and Gradle Commands

When in doubt, give these a shout:

mvn clean install to make sure Maven gets the memo about dependencies.
gradle idea for Gradle projects, a good way to get IntelliJ back in sync.

Check for Plugin Conflicts

Plugins can be tricksters. Clover, for instance, changes bytecode and can lead to misinterpretations.

Correct Handling of Modules

Manually remove and re-add modules, ensuring they have been invited to the Maven or Gradle party.

Library Directory

Ensure you don't have any wallflower libraries. All libraries should be in proper directories for IntelliJ to recognize them.

Additional investigations

In some rare cases, the Jedi tricks might not be enough. Let's explore some further paths together:

Check Global Libraries and SDKs

Like checking for hidden Easter eggs, make sure your global libraries are set correctly (File > Project Structure > Global Libraries).

Maven Profiles and Properties

For Maven projects, profile settings are important to not exclude necessary dependencies. A wrong setting here might make the "Package doesn't exist" play peek-a-boo with you. Similar attention is needed for pom.xml properties.

Artifact Coordinates

Ensure your pom.xml is not playing Twister. The groupId, artifactId, and version should be correct and matching the library you aim to use.

Inspect .iml Files

Think of .iml files as roadmaps for each project module. Open them to ensure the routes (paths) and pit-stops (dependencies) aren't leading IntelliJ astray.