webforJ Webswing Integration Tutorial

This tutorial demonstrates how to integrate existing Java Swing applications into webforJ web applications using the WebswingConnector component.

Overview

The project consists of two applications:

1. Swing Application (custom-table-app) - A traditional Java Swing customer management table
2. webforJ Application (webforj-webswing-integration) - A web app that embeds the Swing app

This architecture enables progressive modernization: embed your existing Swing apps today, then gradually replace them with webforJ components over time.

Prerequisites

• Java 21+
• Maven 3.9+
• Webswing Server (for running the Swing app in web mode)

Quick Start

1. Build the Swing Application

cd custom-table-app
mvn clean package
# Creates custom-table-app.jar

The Swing app automatically detects if it's running under Webswing and adapts its behavior:

• Standalone mode: Shows standard Swing dialogs for editing
• Webswing mode: Communicates with the webforJ wrapper via events

2. Deploy to Webswing Server

Use your Webswing admin console at http://localhost:8080/admin to add and configure your swing app.

In the admin console, configure:

• Application Name: becomes part of the URL path (e.g., custom-table-app → http://localhost:8080/custom-table-app/)
• Main Class: the entry point of your Swing app
• Classpath: path to your app JAR and dependencies
• JVM Arguments: memory settings, system properties, and other JVM options
• Home Directory: working directory for the app

Note: Make sure to move your previously built custom-table-app.jar to the folder you set as your classpath.

After configuration, your Swing app will be accessible at http://localhost:8080/custom-table-app/

3. Run the webforJ Application

cd webforj-webswing-integration
mvn spring-boot:run

Open http://localhost:8090 to see the integrated application.

How It Works

WebswingConnector Component

The WebswingConnector embeds Webswing-hosted applications directly in your webforJ app:

@Route("/")
public class CustomerTableView extends Composite<FlexLayout> {

  public CustomerTableView(@Value("${webswing.connector.url}") String webswingUrl) {
    WebswingConnector connector = new WebswingConnector(webswingUrl);
    connector.setSize("100vw", "100vh");

    // Handle events from Swing app
    connector.onAction(event -> {
      if ("select-customer".equals(event.getActionName())) {
        // Show webforJ dialog for editing
      }
    });

    self.add(connector);
  }
}

Bidirectional Communication

Swing → webforJ: The Swing app sends events using Webswing API:

if (isWebswing) {
  api.sendActionEvent("select-customer", gson.toJson(customer), null);
}

webforJ → Swing: The webforJ app sends commands back:

connector.performAction("update-customer", gson.toJson(customer));

Configuration

Configure the Webswing URL in application.properties:

# Webswing connector configuration
webswing.connector.url=http://localhost:8080/custom-table-app/

# Server configuration
server.port=8090

Architecture Benefits

This integration pattern provides:

• Zero modification deployment - Run existing Swing apps in the browser immediately
• Progressive modernization - Replace Swing components with webforJ gradually
• Hybrid applications - Combine web UI with specialized desktop functionality
• Investment protection - Preserve years of business logic development

Learn More

• webforJ Official Documentation
• Webswing Official Site
• Spring Boot with webforJ