The extension suggests code completions for your YAML configuration files. (The available configuration properties and their values are collected by scanning your source code and the Micronaut libraries.)

The extension also provides code completion for your Java source code via the Extension Pack for Java from Microsoft. This gives you all the IDE features that you would expect from IntelliSense, as well as automatically highlighting errors as you type.

You can easily navigate to Micronaut-specific elements of your source code via the Go to Symbol in Workspace command.

Run the Go to Symbol in Workspace command using Ctrl+T (Cmd+T on macOS) and enter the prefix:

• @/ to show all defined request mappings
• @+ to show all defined beans

You can display all beans and request mappings defined by a Micronaut or GDK application in the BEANS and ENDPOINTS views of the Micronaut Tools activity bar.

If Monitoring and Management capabilities are enabled when the extension launches an application (or connects to an existing application), beans and endpoints available in the application are indicated with a green icon. Disabled beans are indicated with an orange icon, and their tooltips provide additional information. See Monitor and Manage Your Micronaut Application for details.

You can search/filter the items in these views using a dedicated action available in the view captions or using the find shortcut (Ctrl+F or Cmd+F on macOS).

Clicking a node in one of these views navigates to the corresponding source code, similar to the Go to Symbol in Workspace command. You can also use the dedicated context menu action Go to Symbol to open the source code for the bean or request mapping.

The request mapping nodes in the ENDPOINTS view also provide two additional actions:

• Open in Browser to open the GET endpoint in a web browser.
• Compose REST Query to insert the corresponding query into a dedicated text document. For details, see the section Compose REST Queries.

Similar actions are also available in the code editor as Code Lens actions.

If an endpoint require parameters, a dialog box is provided for you to enter parameter values before calling the endpoint.

To easily debug and test the REST API of your application, the ENDPOINTS view provides smooth integration with a third-party extension REST Client.

To compose a REST query, invoke the Compose REST Query action for an endpoint either from the ENDPOINTS view or by using the corresponding Code Lens action in the code editor. A dedicated text document is opened, and the corresponding query is inserted. For the POST and PUT queries, the necessary request body is pre-created in the code editor in a form of parameterized code snippet. Use the REST Client features to invoke and process the query.

Note: If the REST Client extension is not installed when you invoke the Compose REST Query action, a notification is displayed offering to quickly install it.

Since version 4.0, Micronaut Framework enables you to embed an evaluated expression in an annotation value using the #{...​} syntax. This is known as the Micronaut Expression Language.

The extension provides full editor support for the Micronaut Expression Language, including:

• Code completion (as shown below)
• Syntax highlighting
• Documentation hovers for Java elements and Micronaut configuration properties
• Code navigation to Java elements and Micronaut configuration properties

You can visually configure and control your Micronaut or GDK application using the APPLICATIONS view of the Micronaut Tools activity. The view displays all Micronaut and GDK applications in the current workspace:

You can invoke the following actions and configure the following settings:

Application Node (for example, "micronaut-petclinic")

Represents the logical application, and provides the following actions based on the state of your application:

• Run Application Without Debugging: to run your application with no debugging, see Run Your Micronaut Application.
• Run Application in Continuous Mode: to run your application in continuous mode, see Live Reload Your Application.
• Start Debugging Application: to run your application with debugging, see Debug Your Micronaut Application.
• Connect to Externally Started Application: to connect to a local or remote application that is already running, based on the address:port defined by the Address node, see Connect to Your Running Micronaut Application.
• Stop Application: to stop an application you launched.
• Disconnect from Application: to disconnect from an application to which you connected.
• Open Application in Browser: to open your application in a web browser using the address:port defined by the Address node.

Subproject Node (GDK applications only)

Represents a subproject/module of a modular GDK application. All the settings you configure in this view are stored and used in context of this subproject. It provides the following action:

• Change Subproject: to switch the subproject context.

Address Node

Defines the address:port to start a local application, or to connect to an application that is already running. It provides the following action:

• Edit Application Address: to customize the application address. To restore the default value (http://localhost:8080), enter an empty address.

Environments Node

Defines the active Micronaut environment(s) for an application you launched, and provides shortcuts to the corresponding configuration files. The default by project value means the environments are defined by the project. A custom value forces the application to start with the defined active environments. It provides the following actions:

• Edit Active Environments: to define which environments will be active for the application you launch - enter an empty value to accept the default (by project).
• Configure Environment Properties: shortcuts to create new (or edit existing) configuration files for application environments.

Note: For more information about Micronaut Environments, see The Environment.

Monitoring & Management Node

Enables you to configure the monitoring and management capabilities for an application you launched (for more information, see Monitor and Manage Your Micronaut Application). The default by project value means the monitoring and management capabilities are defined by the project. Change the value to enabled to add the required dependencies (if needed) to the project build file, and configure the required properties to enable the monitoring and management capabilities. It provides the following action:

• Edit Monitoring & Management Availability: to force the application to launch with the monitoring and management capabilities enabled (enabled). The default by project value means the monitoring and management capabilities will be available as configured by the project.

Micronaut Control Panel Node

Enables you to configure the Micronaut Control Panel to view and manage the state of an application you launched (for more information, see Observe Your Application using the Micronaut Control Panel). The default by project value means the Micronaut Control Panel will be available as defined by the project. Change the value to enabled to add the required dependencies (if needed) to the project build file, and configure the required properties to enable the Micronaut Control Panel. It provides the following actions:

• Edit Micronaut Control Panel Availability: to force the application to launch with the Micronaut Control Panel enabled (enabled). The default by project value means the Micronaut Control Panel will be available as configured by the project.
• Open Micronaut Control Panel in Browser: opens the Micronaut Control Panel in a web browser.

The easiest way to run your Micronaut application is to view the Application class in the editor and click Run above the main() method, as shown here.

Note: If you have defined a database connection, see Connect to an Oracle Autonomous Database, then the database connection details will be provided to your running application through an argument file when running the application in this way.

Alternatively, use the Run Application Without Debugging action in the APPLICATIONS view of the Micronaut Tools activity, or invoke Run Without Debugging from the Run menu.

Micronaut can automatically recompile and restart your application (or its parts) when it detects changes to your source code. (This is called "Continuous Mode".) To run your Micronaut application in this mode, view the Application class in the editor and click Run with Micronaut Continuous Mode above the main() method, as shown here.

Alternatively, use the Run Application in Continuous Mode action in the APPLICATIONS view of the Micronaut Tools activity.

Alternatively, select Run and Debug from the Activity Bar and click Create a launch.json file. When prompted, select Java as the debugger. A configuration labeled with "Continuous" will be created for your Micronaut application main class(es), similar to this example:

Select the newly added configuration in the Run and Debug view, then click Run.

The easiest way to debug your Micronaut application is to view the Application class in the editor and click Debug above the main() method, as shown here.

Alternatively, use the Start Debugging Application action in the APPLICATIONS view of the Micronaut Tools activity, or invoke Start Debugging from the Run menu.

Use the Connect to Externally Started Application action in the APPLICATIONS view of the Micronaut Tools activity to observe an application. When you have connected to an application, you can:

• Monitor basic telemetry, such as CPU/memory usage
• Check active Micronaut environments
• Check available management endpoints
• Check the availability of the Micronaut Control Panel
• Check the availability and status of defined beans
• Check the availability of defined endpoints
• Change runtime configuration (such as logging levels and caches)
• Invoke management actions (such as Refresh and Server Stop)

The application must already be running on the address:port defined by the Address node. To stop observing the connected application, use the Disconnect from Application action.

Based on the monitoring and management capabilities or the Micronaut Control Panel availability in the connected application, various information and actions will be displayed in the Micronaut Tools activity views. See Monitor and Manage Your Micronaut Application and Observe Your Application using Micronaut Control Panel for details.

The Micronaut Tools activity views can display data and invoke actions provided by the supported Micronaut Management & Monitoring Endpoints.

The application must be set up and configured to provide the endpoints. This can be configured either manually (the Monitoring & Management node displays by project), or automatically by setting the Monitoring & Management node to enabled. This will add the required dependencies for the supported features to the project build file, and configure the launched application properties to enable the features in runtime.

Note: To fully disable all enabled monitoring & management capabilities for a project, the Monitoring & Management node must be set to by project, and the added dependencies must be manually removed from the project build file.

Based on the monitoring and management capabilities available in the launched or connected application, these information and actions will be displayed in the Micronaut Tools activity views:

APPLICATIONS view

• Refresh Application State action: to destroy all refreshable beans in the context. The beans are re-instantiated upon further requests. (Requires the Refresh endpoint.)
• Stop Server action: to stop an application started externally (requires the Server Stop endpoint).
• List of active environments: displayed for the Environments node (requires the Environment endpoint).
• Actual monitoring & management capabilities availability: displayed for the Monitoring & Management node, the tooltip displays all currently available endpoints.

BEANS and ENDPOINTS Views

The beans available in a running application are indicated with a green icon; disabled beans are indicated with an orange icon; their tooltips provide additional information from the underlying framework. (Requires the Beans endpoint.)

The endpoints available in the running application are indicated with a green icon. (Requires the Routes endpoint.)

MONITORING & MANAGEMENT view

• Monitoring node:
  • Uptime, CPU, Heap, Non Heap: requires the Metrics endpoint with basic Micrometer core metrics configured.
  • Disk: requires the Health endpoint.
• Management node:
  • Loggers: displays number of configured loggers, with details in a tooltip. Use the Configure Loggers action to re-configure existing loggers, or create a new logger in the running process. (Requires the Loggers endpoint.)
  • Caches: displays number of available caches, with details in a tooltip. Use the Invalidate Caches action to invalidate selected caches in the running process. (Requires the Caches endpoint.)

The APPLICATIONS view of the Micronaut Tools activity provides a link to the Micronaut Control Panel if your application is set up and configured to provide the Micronaut Control Panel module. You can configure your application either manually (the Micronaut Control Panel node displays by project), or automatically by setting the Micronaut Control Panel node to enabled. This will add the required dependencies to the project build file, and configure the launched application properties to enable the feature at run time.

Note: To fully disable the Micronaut Control Panel for a project, set the Micronaut Control Panel node to by project, and manually remove the added dependencies from the project build file.

If available, you can open the Micronaut Control Panel in a web browser using the Open Micronaut Control Panel in Browser action in the Micronaut Control Panel node.

Note: The Micronaut Control Panel was first introduced as an experimental feature of the Micronaut 4 framework, and may not work correctly with some other Micronaut features such as databases, caches, and so on. If your application fails to start, or works incorrectly after enabling the Micronaut Control Panel, you must manually disable the Micronaut Control Panel.

To package your application as a runnable JAR file, follow these steps:

1. Select Command Palette from the View menu. Enter "Micronaut Tools" and invoke the Micronaut Tools: Build... command.

2. Select the compile build goal from a list of available goals.

   

3. When the compilation is complete, invoke the Micronaut Tools: Build... command again. This time, select the package goal, which will package your application into a JAR file.

If you have installed Oracle GraalVM, you can use GraalVM Native Image to create a native executable from your application. GraalVM Native Image creates an executable file with all the application classes, dependent library classes, dependent JDK classes, and a snapshot of the application heap. The benefits include a dramatic reduction in startup time and lower overall memory consumption.

Note: The time to build an executable depends on application size and complexity.

To create a native executable, follow these steps:

1. Select Command Palette from the View menu. Enter "Micronaut Tools" and invoke the Micronaut Tools: Build... command.

2. Select the compile build goal from a list of available goals.

   

3. When the compilation is complete, invoke the Micronaut Tools: Build... command again. This time, select the nativeImage goal, which creates a native executable from your application.

   • If your application is built with Maven, the goal runs the command mvnw package -Dpackaging=native-image. The resulting native executable will be in the target/native-image/ directory.

   • If your application is built with Gradle, the goal runs the command gradlew nativeCompile. The resulting native executable will be in the build/native/nativeCompile/ directory.

To run your Micronaut application as a native executable, open a terminal by selecting New Terminal from the Terminal menu, then run the following command:

• If you used Maven: ./target/<executable-name>
• If you used Gradle: ./build/native/nativeCompile/<executable-name>

For more information, see the Micronaut documentation.

Note: If you are using VS Code on the Windows platform, invoke the Micronaut Tools: Build Native Image command from the Command Palette.

You can build a container image of your Micronaut application, or create a container image of an executable created by GraalVM Native Image. You can then deploy the container image.

To build and deploy a container image of your application, follow these steps:

1. Select Command Palette from the View menu. Enter "Micronaut Tools" and invoke the Micronaut Tools: Deploy... command.

2. Select select one of the goals from the list:

   • To deploy a containerized Micronaut application, select the dockerPush goal.
   • To deploy a containerized native executable, select the dockerPushNative goal.

To configure your application's container registry, see the documentation for Micronaut Maven Plugin/Micronaut Gradle Plugin.

Prerequisites:

• An Oracle Cloud Infrastructure (OCI) account.
• The OCI DevOps Tools extension (part of the Graal Development Kit for Micronaut Extension Pack).

The OCI DevOps Tools extension provisions build and deployment pipelines for:

• An OCI native executable container: a containerized native executable
• An OCI Java container: a containerized Micronaut application

It can also provision a cluster to run your container on Oracle's Container Engine for Kubernetes. For more information about using the OCI DevOps Tools Extension, see Using the Graal Development Kit and OCI DevOps Tools Extensions in VS Code.

Prerequisites:

• An Oracle Cloud Infrastructure (OCI) account.

Cloud Assets panel shows the Micronaut OCI Properties to be set. These are read from project artefacts provided in the project pom.xml or build.gradle configuration files. When the OCI configuration file .oci/config is present, it enables you to set various OCI assets (resources) needed for the project runtime.

Different actions are available, depending on the OCI assets (resources) that are selected.

Prerequisites:

• An Oracle Cloud Infrastructure (OCI) account
• An SSH key pair
• A Compute Instance in OCI

To establish an SSH connection to your Compute Instance:

1. Expand the ORACLE CLOUD ASSETS view in the Explorer panel and click Select Compute Instance.
2. Choose a compartment in which your Compute Instance was created.
3. Select your Compute Instance.
4. Hover over the previously added Compute Instance in the ORACLE CLOUD ASSETS view and click the left most, "terminal", icon.
5. A terminal window opens, as well as a guide on how to set up the SSH keys.

Prerequisites:

• An Oracle Cloud Infrastructure (OCI) account
• An SSH key pair
• A Compute Instance in OCI
• Docker installed on the Compute Instance

To build and run a container image on a Compute Instance:

1. Expand the ORACLE CLOUD ASSETS view in the Explorer panel and click Select Container Repository.
2. Choose a compartment in which the Container Repository was created.
3. Select your Container Repository.
4. Hover over the previously added Container Repository and click the left most icon.
5. Enter the image tag name and click Enter.
6. After the image is successfully pushed to the Container Repository, it will appear as a child item under the Container Repository.
7. Hover over the container image again, and click the right most "play" icon to run the image on a Compute Instance.
8. A terminal window opens, as well as a guide.

Prerequisites:

• An Oracle Cloud Infrastructure (OCI) account

To generate application properties needed to configure the selected OCI Assets (resources), do the following:

1. Click on the left most icon of the ORACLE CLOUD ASSETS view in the Explorer panel or run the Create External Config Properties command:

   

2. Select a configuration target.

• If the Open a preview of the config in the editor option is selected, it will open a new window with generated properties where it can be copied from.

• If the Upload the config to a ConfigMap artifact in an OCI DevOps Project option is selected, it requires to select a compartment and then a DevOps project in which it will update the ConfigMap artifact.

  

Prerequisites:

• An Oracle Cloud Infrastructure (OCI) account

To generate the OCI policies required for the application to access OCI Assets (resources):

1. Click on the "key" icon of the ORACLE CLOUD ASSETS view in the Explorer panel or run the Create OCI Policies command.

   

2. A new window appears with a policy file. Copy the contents of the file and follow the instructions on how to create a policy.

By connecting to an Oracle Autonomous Database in VS Code, you can browse the schemas of any existing databases you may have and then quickly create a REST API that exposes them.

Prerequisites:

• An Oracle Cloud Infrastructure (OCI) account.

To connect to an Oracle Autonomous Database:

1. Expand the DATABASES view in the Explorer panel and click Add Oracle Autonomous DB. If the view contains existing databases, skip to step 6.
2. Select the compartment containing your database from the list of compartments.
3. From the list of databases, select your database.
4. Enter the username for the database.
5. Enter the password for the database. The database will be added to the DATABASES view in the Explorer panel.
6. Select the database in the view, then right-click. Select Connect to Database from the menu.

To change the properties of a database connection, select the database in the DATABASES view, right-click and then select Properties from the menu.

Note: Disconnect from the database before attempting to change its properties. You cannot change the properties of a connected database.

To select a database as the Default Connection, select the database in the DATABASES view, right-click and then select Set as Default Connection from the menu.

Note: The database password is stored using an OS-specific secure storage mechanism. This will be one of the following: macOS keychain; KDE Wallet; GNOME/Keyring; Windows Data Protection API;

When running or debugging a Micronaut application from within the editor, a temporary argument file is created that contains any properties required by the application. This may include the database username and password. The contents of this file are provided to the application when it is started. This temporary file is readable only by the user running VSCode and is deleted as soon as the run/debug session finishes.

The Micronaut Tools VS Code extension can store an application's database configuration using OCI Vault. Vault is a service within OCI for securely managing secrets.

To make use of this feature, first create an OCI Vault and Master Encryption Key using the Oracle Cloud Console. Please consult the OCI documentation, previously linked, on how to do this.

If your project uses the OCI DevOps service, then make sure the OKE Deployments Pipelines are created before you proceed.

To store your application database connection details using OCI Vault and for these to be made available to your application when you deploy to OKE using the OCI DevOps service, you must:

1. Connect to an Oracle Autonomous Database as described above in the Connect to an Oracle Autonomous Database section.

2. Ensure your Micronaut project configuration file contains the micronaut-oraclecloud-vault dependency.

   • pom.xml

    <dependency>
     <groupId>io.micronaut.oraclecloud</groupId>
     <artifactId>micronaut-oraclecloud-vault</artifactId>
    </dependency>
   

   • build.gradle

     implementation("io.micronaut.oraclecloud:micronaut-oraclecloud-vault")
   

3. Right-click the database name in the Databases panel and choose Add to OCI Vault

   

4. From the list of compartments, select one with an existing vault. (If there is more than one vault, select the one to store your database properties.)

5. From the list of keys, select the key to encrypt your database properties. If there is only one key, this step is skipped and the default encryption key is used.

6. Provide a custom Datasource Name.

7. Click Enter. The database properties are stored in your vault. A notification is shown at the bottom of the VS Code window.

8. If the project is stored in OCI DevOps, then running the deployment pipelines from within the OCI DevOps panel will use the Database properties stored in the vault from the previous steps.

Note: If OKE Deployment Pipelines are modified as described above, the OKE ConfigMap named <project_name>_oke_configmap is used. The deployment then uses the database properties stored in your OCI Vault to run a Micronaut application in OKE securely and seamlessly. Learn more about this in the OCI DevOps Tools extension documentation.

After you have created a connection to an Oracle Autonomous Database, you can quickly create Micronaut Data entity classes for the tables within the database.

Prerequisites:

• You have created a connection to a database with an existing schema. (See above.)
• You have selected the database as the Default Connection. (See above.)

To create Micronaut Data entity classes:

1. Create a new Micronaut project in VS Code (or open an existing one).
2. Create a new Java package in your project, for example, com.example.micronaut.entities.
3. Right-click the package name and select New From Template... from the menu.
4. When prompted, select Micronaut, then Micronaut Data Entity Classes from Database.
5. From the list of tables, select the tables for which you want to create corresponding entities.
6. Click Enter.

In a similar way, we can also create Micronaut Data repository interfaces - note this requires that you have already created entity classes (see above):

1. Create a new Micronaut project in VS Code (or open an existing one).
2. Create a new Java package in your project, for example, com.example.micronaut.repositories.
3. Right-click the package name and select New From Template... from the menu.
4. When prompted, select Micronaut, then Micronaut Data Repository Interfaces from Entity.
5. Choose if Repository Interfaces should be based on CRUD or Pageable. The default is CRUD.
6. From the list of entities, select the entities for which you want to create corresponding repository interfaces.
7. Click Enter.

By creating Controllers that expose your Micronaut Data repository interfaces, you can quickly turn them into a REST API. Create your Micronaut Data entity and repository interfaces first and then:

1. Right-click the package name and select New From Template... from the menu.
2. When prompted, select Micronaut, then Micronaut Controller Classes (from Data Repositories).
3. From the list of repositories, select one or more items. You can select all, a selection of them.
4. Click Enter

A controller that has access to the data repository is generated for each of the Micronaut Data repository interfaces that you selected in the wizard. By default, it contains a REST endpoint to access the repository's findAll() method in its list() method.

Other REST Endpoints accessing a repository can be added to the controller. It is possible to add various get, save, update, and delete endpoint methods delegating to methods available in the corresponding repository. This can be done either through code completion (select the desired method from the list) or directly from the editor: Source Action... | Generate Data Endpoint....

Currently, variants of the get(), save(), update(), and delete() methods are provided.

To generate a test class with a test method for every endpoint method of a controller class, invoke Source Action... | Generate Micronaut Endpoint Tests... inside of the controller class opened in the editor.

This extension modifies the Java environment so that the application is launched using the build system (Gradle, Maven). Not all environment customizations are supported and for some projects this functionality may need to be turned off.

To enable or disable the enhanced Run feature, navigate to File - Preferences - Settings, locate Micronaut Tools extension section and turn on/off the Use build system to run or debug applications. The relevant setting (in JSON format) is micronaut-tools.buildsystemExecution

In some configurations the Enhanced Run feature code lenses, Run | Debug | Run with Micronaut Continuous Mode, are not displayed for Gradle projects when Gradle for Java extension is enabled. To resolve this, disable Gradle for Java extension, reload VS Code, and then enable Gradle for Java again.

The Apache NetBeans Language Server for Java fails on Linux and macOS if the path of VSCode extensions directory contains a space, for example /User/great code/.vscode/extensions. (The extensions directory contains all VSCode extensions are installed.) The default path is:

• Windows %USERPROFILE%.vscode\extensions
• macOS ~/.vscode/extensions
• Linux ~/.vscode/extensions

Change the path by removing any spaces:

• Permanently, by setting the environment variable VSCODE_EXTENSIONS in the appropriate profile file (for example, .bash_profile); or
• Temporarily by launching VSCode from the command line with the option --extensions-dir, for example $ code --extensions-dir "/User/code_user/extensions_dir".
• It cannot be changed in VSCode Settings.

When running a Micronaut or GDK application in debug mode, you might sometimes experience this error in VS code:

This is caused by a long project build and run time which exceeds a default timeout in VS Code (20 seconds) for which VS Code waits for a debuggee process to connect to a debugger. It can also be caused by Test Resources enabled in a Micronaut or GDK application project which sometimes start longer. The workaround is to disable those. In a Maven project:

• Open pom.xml being executed
• Change this property to false: <micronaut.test.resources.enabled>false</micronaut.test.resources.enabled>

In a Gradle project:

• Open build.gradle being executed
• Add the following code into the micronaut { section:

testResources {
      enabled.set(false)
  }

Rerun the project using Debug on the CodeLens of the application main() method or Debug from the Micronaut panel.