My Application

A Spring Boot + Vaadin project. Build your UI in pure Java — no HTML, no JavaScript.

New to Vaadin? The 5-minute Quickstart walks you from here to your first running app, a live code change, and an AI-assisted edit with Copilot.

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Fastest start — no plugin needed

From the project folder:

./mvnw spring-boot:run        # Windows: mvnw.cmd spring-boot:run

No system Maven required — the wrapper is included. Then open http://localhost:8080.

The first start takes ~30 seconds while Maven downloads dependencies. You'll get a runnable Task List app: a data grid (Description / Due Date / Creation Date), a Create button, and an empty-state message. When you see that, you're running.

Port 8080 already in use? Stop the other process, or set server.port=8081 in src/main/resources/application.properties and open that port instead.

To stop the app: press Ctrl+C in the terminal (or the red Stop button if you launched from your IDE).

Optional upgrade — instant hotswap

Running with spring-boot:run works, but Java code changes need a restart. For live reload — edit Java, see it in the browser without restarting — install the Vaadin plugin and start the app through it:

• IntelliJ IDEA: install Vaadin from the JetBrains Marketplace → Debug using Hotswap Agent (dropdown next to Run). Just installed it? Let IntelliJ finish indexing, or restart it, if the menu item isn't there yet.
• VS Code: install the Vaadin extension → Vaadin: Debug using Hotswap Agent from the command palette.
• Eclipse: install the Vaadin plugin → right-click the project → Run As → Vaadin Application.

This is what makes the edit-and-see-it loop feel instant — and it's required for the AI edits in Vaadin Copilot.

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Day 2: make your task list interactive (~10 min)

Your app lists tasks. Let's make a row do something when you click it.

1. Add a click listener (by hand). In src/main/java/com/example/examplefeature/ui/TaskListView.java, add this after the taskGrid.addColumn(...) block:

taskGrid.addItemClickListener(event ->
    Notification.show("Due: " + Optional.ofNullable(event.getItem().getDueDate())
        .map(LocalDate::toString)
        .orElse("no due date")));

Add the import: import com.vaadin.flow.component.notification.Notification;

Save and click a task — a notification shows its due date. That's a server-side event handler, in pure Java.

2. Let Copilot finish it. Open Copilot (bottom-right toolbar → Edit mode), click the AI assistant, and try:

When a task row is clicked, open a dialog showing its description, due date, and creation date, with a Close button.

Copilot writes the dialog into TaskListView.java for you. Open the file — your new code is right there.

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Ask your AI assistant about Vaadin (optional)

If you use Claude Code, Cursor, or another AI coding assistant, connect it to the Vaadin MCP server so it answers against real Vaadin docs and the exact API of your installed version — instead of guessing from outdated training data.

# One-time setup — see https://vaadin.com/docs/latest/building-apps/mcp

A .mcp.json is included (commented out by default). Uncomment it, or run the setup command above, to activate.

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Build for production

./mvnw package
java -jar target/*.jar

Learn more

• Vaadin Quickstart — the 5-minute getting-started path
• Components — 50+ UI components, all callable from Java
• Vaadin Copilot — visual + AI editing in the browser
• Full documentation