intellij-sdk-code-samples/topics/reference_guide/project_model/sdk.md

Configuring and getting information about a project SDK.

SDK

Product Help: SDKs

Every project uses a Software Development Kit (SDK). For Java projects, the SDK is referred to as the JDK (Java Development Kit). The SDK determines which API library is used to build the project. If a project is multi-module, the project SDK by default is common for all modules within the project. Optionally, individual SDKs for each module can be configured.

Getting Project SDK Information

The information about the project SDK is accessed via ProjectRootManager like the following example shows

Sdk projectSdk = ProjectRootManager.getInstance(project).getProjectSdk();

Getting and Setting Project SDK Attributes

• To get the project-level SDK:

  Sdk projectSdk = ProjectRootManager.getInstance(project).getProjectSdkName();
  

• To get the project-level SDK name:

  String projectSdkName = ProjectRootManager.getInstance(project).getProjectSdkName();
  

• To set the project-level SDK:

  ProjectRootManager.getInstance(project).setProjectSdk(sdk);
  

• To set the project-level SDK name:

  ProjectRootManager.getInstance(project).setProjectSdkName(name, sdk.getSdkType().getName());
  

See the project_model code sample to get more familiar with SDK manipulation toolset.

Available SDKs

ProjectJdkTable can be used to query and modify configured SDKs.

Working with a Custom SDK

To create a custom SDK, provide a class extending SdkType, leave saveAdditionalData() blank, and register it in the com.intellij.sdkType extension point.

To make SDK settings persistent, override setupSdkPaths() and save settings by modificator.commitChanges():

@Override
public boolean setupSdkPaths(@NotNull Sdk sdk, @NotNull SdkModel sdkModel) {
  SdkModificator modificator = sdk.getSdkModificator();
  modificator.setVersionString(getVersionString(sdk));
  modificator.commitChanges(); // save
  return true;
}

To let a user select an SDK, see ProjectJdksEditor.

However, it is not recommended to use "SDK" in non-IntelliJ IDEA IDEs. Although "SDK" is available in most JetBrains products, ProjectJdksEditor is specific to Java, making the operation around "SDK" difficult. The recommended way of managing "SDK" settings is to create a CustomStepProjectGenerator implementation and save settings in a PersistentStateComponent.

Assisting in Setting Up an SDK

Prompting the user with a notification to set up an SDK can help them get up-and-running with a plugin faster. Use com.intellij.projectSdkSetupValidator extension point to register an implementation of ProjectSdkSetupValidator to notify the user if they are missing an SDK.

The following is a simplified example that checks whether an instance of "DemoSdk" has been configured in the project when the user opens a "DemoFileType":

class DemoProjectSdkSetupValidator : ProjectSdkSetupValidator {
  override fun isApplicableFor(project: Project, file: VirtualFile): Boolean {
    return file.fileType == DemoFileType
  }

  override fun getErrorMessage(project: Project, file: VirtualFile): String? {
    if (ProjectJdkTable.getInstance().getSdksOfType(DemoSdkType.getInstance()).isEmpty()) {
      return "No DemoSdks are configured for this project!"
    }
    return null
  }

  override fun getFixHandler(project: Project, file: VirtualFile):
        EditorNotificationPanel.ActionHandler {
    return SdkPopupFactory.newBuilder()
        .withProject(project)
        .withSdkTypeFilter { it is DemoSdkType }
        .updateSdkForFile(file)
        .buildEditorNotificationPanelHandler()
  }
}

Within DemoProjectSdkSetupValidator:

• isApplicableFor() checks what condition(s) should be met to run the validation.
• getErrorMessage() runs the validation and return an appropriate error message if the validation fails.
• If the validation is successful, then it should return null.
• getFixHandler() returns an EditorNotificationPanel.ActionHandler that enables the user to execute a quick-fix to resolve the validation issue.

ProjectSdkSetupValidator will not work in IntelliJ Platform-based IDEs such as PyCharm. In such cases, you should register an implementation of EditorNotifications.Provider at the com.intellij.editorNotificationProvider extension point and override the createNotificationPanel() method with the conditionality and panel setup you want.

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