The status of Java Swing - And why consider modernization

Java Swing has been supporting enterprise applications for decades. However, Swing is now in maintenance mode and no longer reflects the state of the art in application development. But does that mean that Java Swing is deprecated, and what are the alternatives for organizations that use Swing?

What is Java Swing used for?

Introduced in 1997 as part of the Java Foundation Classes (JFC), the Java Swing framework is a GUI toolkit for building desktop apps using familiar Java code. It includes plenty of pre-built UI components, making it easy for developers to quickly create interactive desktop apps.

Java Swing is used broadly – but it’s particularly popular in the enterprise. Enterprise applications built with Swing include complex business apps such as CRM, ERP, and various critical internal tools, many of which are in daily use.

Is Java Swing deprecated?

Java Swing remains an integral part of Java Standard Edition (Java SE), and Oracle continues to provide official support. In other words, Java Swing is not deprecated in the strictest sense of the word.

While Swing is not deprecated, it's important to note that Java Swing is in maintenance mode. Maintenance mode means that Oracle provides only ongoing bug fixes and security updates for Swing. Maintenance ensures the stability and security of Java Swing, but there is no active development of new features or major enhancements.

So far, Oracle has not announced any plans to deprecate Swing in the foreseeable future – so you can expect ongoing security patches and bug fixes.

This “hanging in the air” status – neither deprecated nor under active development – reflects the fact that Swing is still supporting many desktop applications, particularly in the enterprise environment.

What is the outlook for Swing?

Supported, yes, but Java Swing’s evolution has stagnated. Forward-thinking developers are increasingly exploring modern alternatives aligned with today’s development trends.

That doesn’t mean Java Swing is going away anytime soon. The extensive use of and investment in Java Swing apps across the enterprise means we’ll likely see Oracle continue to offer critical support for Swing in the foreseeable future.

Nonetheless, the focus is on maintaining the existing functionality and addressing bugs and security threats. We do not expect to see significant new features or major enhancements.

Because Swing is no longer being enhanced, its role in newly built apps is diminishing as modern web frameworks such as Vaadin Flow gain traction thanks to better UX and improved performance. That said, the Java Swing community remains active, and Swing developers continue to share knowledge and resources online.

Why some developers still use Swing

Modern frameworks offer a better alternative to Java Swing, but many developers continue to use Swing. The biggest argument for doing so is maintaining complex, legacy apps.

Organizations relying on large, complex applications built on Swing may not be able to undertake the cost and effort of wholesale migration to a new platform. As much as progress can’t be delayed forever, replacing legacy applications can be expensive and cause disruption in daily work, so using Swing with Oracle's ongoing caretaking support can make sense.

Developers with extensive Java Swing experience may also find it a comfortable and familiar choice – which, for the moment, may offer these developers faster development cycles and easier maintenance steps.

After all, with the exception of Vaadin Flow, which uses 100% Java, many modern frameworks rely on languages such as JavaScript, JSX, CSS, etc. Switching to web frameworks such as React, Angular, Vue.js, or next.js, therefore, involves a substantial learning curve for Swing developers.

There’s also something to be said for framework maturity. Over twenty years, Swing built a mature and stable framework. Swing has a wealth of resources, documentation, and community support – all of which can “swing” the odds for certain projects.

Limitations of Java Swing

Continuing to use Swing makes sense under some conditions, but sometimes, this decision is in balance. It most likely doesn’t make sense to start a green field project using Java Swing. For everything in between, it’s worth considering the drawbacks of Swing when deciding whether to perpetuate existing Swing-based projects:

• Outdated UI: Swing's design aesthetics and user experience principles are rooted in an earlier era of software development. Compared to web apps, Swing appears outdated and less visually appealing.
• No modern web standards: Swing doesn't natively support modern web standards like HTML5, CSS3, or JavaScript. Therefore, it is hard to integrate Swing applications with web-based components or services.
• Lack of support for mobile devices: The lack of support for web standards also means that Swing is not a good fit for mobile platforms. Mobile apps built with Swing require significant workarounds and result in subpar UX on smaller screens and touch-based devices.
• Maintaining Swing applications: The framework's complexity and the lack of modern development tools and practices can make it tough to maintain Swing apps, whether refactoring code or adding new features.
• Resource consumption: Apps built with Swing can consume significant system resources, particularly memory. This can be a concern for users with older hardware or limited resources.

The disadvantages above amount to a strong argument to look for a replacement for Java Swing. Continuing to rely on Swing will eventually raise concerns about enterprise agility, competitiveness, and user experience.

What is replacing Java Swing?

There are a couple of Java Swing alternatives, each with unique use cases. JavaFX is considered the official successor to Swing. It offers a modern UI and support for CSS styling and FXML. Compared to Swing, JavaFX offers better performance for complex UIs.

SWT (Standard Widget Toolkit) was developed for the Eclipse platform and uses native controls as much as possible. SWT is known for its performance and native appearance.

Vaadin Flow as an alternative to Swing

Vaadin Flow is a full-stack framework designed for Java developers who want to create web apps; it allows developers to build a UI using Java components, connect them to data sources, and manage user interactions.

The component APIs in Vaadin Flow closely mirror those found in Java Swing, making it intuitive for Swing developers to understand. This is a significant advantage over frameworks like JavaFX, which require learning a whole new way of building UIs.

For modern enterprises seeking to develop web- and cloud apps, Vaadin Flow offers a Java-based alternative to Java Swing. While both leverage Java, Vaadin Flow is specifically designed for the web, making it easy to build and deploy web apps with modern UIs.

Comparing Vaadin Flow web framework with Java Swing

Web accessibility with Vaadin Flow

Vaadin Flow also introduces improved scalability and is easier to update and maintain remotely compared to Java Swing, where updates are made on client machines. Flow is also intrinsically better at supporting modern accessibility standards.

Vaadin Flow provides over 50 ready-to-use, full-stack components designed with accessibility in mind, helping you meet both ethical standards and legal requirements. These components adhere to comprehensive accessibility guidelines, streamlining the process of building inclusive web applications that cater to all users.

Growing platform under active development

However, arguably the biggest differentiator is that Vaadin Flow is under active development in alignment with the ongoing shift to web apps that use web- and cloud-centric application frameworks. 

In contrast, Java Swing receives maintenance updates only and will remain firmly chained to the desktop environment.

See the Vaadin roadmap on GitHub -->

The case for modernizing Java Swing applications

Modern web frameworks are popular because they address the limitations of the desktop UI. Breaking free from Java desktop applications built with Swing and moving applications to the web hold benefits including:

• Enhanced UX: Modern web frameworks enable visually appealing UIs that meet contemporary design standards. Pre-built components, responsive layouts, and interactive elements work together to deliver an enhanced user experience.
• Performance and scalability: Web frameworks are designed to handle high traffic loads through client-side rendering, asynchronous communication, and caching mechanisms.

• Shorter development cycles: Modern frameworks and libraries are designed to streamline development, offering more efficient ways to build and maintain applications. This can lead to faster development cycles, as developers can leverage pre-built components, better tooling, and more robust ecosystems.

• Maintenance costs: Modernized applications lead to lower ongoing maintenance due to improved code quality and readability. Thanks to updates with modernized, modular code, bug fixes are easier. There is also a lower dependency on legacy skill sets, reducing specialized maintenance overhead.
• Delivery costs: Post modernization, teams gain accelerated deployment through streamlined CI/CD pipelines - alongside more efficient resource allocation with cloud-native deployment options.

Overall, organizations gain significant long-term savings from reduced technical debt. It also means improved scalability and performance, lowering operational costs. 

Modernized applications also benefit from enhanced security and compliance, reduced risk of incident-related expenses, better resource utilization, and reduced need for extensive hardware upgrades. Learn more about the ten characteristics of modern business apps. 

Is it worth modernizing legacy apps?

It raises the question, though: what if an organization simply isn’t in a position to replace legacy apps? After all, many legacy applications still hold significant value within an organization, built on years of investment and tailored to specific business needs. Simply discarding these applications would be like throwing away valuable assets.

Modernization could be the road forward – taking advantage of the capabilities of existing legacy apps and preserving the value embedded, while unlocking the full potential to meet evolving user and business expectations.

Steps to modernizing Java applications 

Modernizing legacy Java Swing applications may seem daunting, but it helps to have a step-by-step approach and make wise use of the tools at your disposal. We suggest considering the following steps:

• Assess your Swing application: Conduct a thorough review of your Swing application's codebase, UI design, and performance. The aim is to identify outdated components, design flaws, and performance bottlenecks – and to define clear objectives for your modernization project.
•  Plan your migration strategy: Choose from modern web frameworks (like Vaadin Flow) to align with your requirements. Create a detailed roadmap outlining the migration steps, timelines, and resource allocation. 
• Key considerations: A robust testing strategy ensures your modernized application functions correctly. User training really matters if your modernized application has a significantly different interface.

Learn more about how we support our customers through a modernization process.

Depending on the framework you choose, you’ll have access to many tools and resources. For example, Vaadin's Migration Toolkit simplifies the Java Swing migration process.

With the Toolkit, your transformed application sources retain the original structure, naming conventions, comments, and whitespace. Changes made by the transpiler are almost always applied within the same line of code, meaning your developers can confidently take ownership. Compare the Swing to Vaadin Flow migration example below.

public VoyageView() {

    String[] locations = new String[]{"Bayonne", "Berlin", "Bern", "Bilbao", "Birmingham", "Bremen", "Brussels"};
    JList<String> departingCity = new JList<<String>();
    departingCity.setListData(locations);
    JList<String> arrivingCity = new JList<<String>();
    arrivingCity.setListData(locations);

    this.setLayout(new BorderLayout());
    JButton searchButton = new JButton("Search");
    JButton cancelButton = new JButton("Cancel");
    JPanel citySelection = new JPanel(new GridLayout(0,2));
    citySelection.add(departingCity);
    citySelection.add(arrivingCity);
    JPanel buttonBar = new JPanel();
    buttonBar.setLayout(new BoxLayout(buttonBar, BoxLayout.Y_AXIS));
    buttonBar.add(searchButton);
    buttonBar.add(cancelButton);
    this.add(buttonBar, BorderLayout.WEST);
    this.add(citySelection, BorderLayout.CENTER);
    departingCity.addListSelectionListener(new ListSelectionListener() {
     @Override
       public void valueChanged(ListSelectionEvent e) {
        if (arrivingCity.getSelectedValue() == null) return;
        if (arrivingCity.getSelectedValue().equals(departingCity.getSelectedValue())) {
          arrivingCity.clearSelection();
        }
    }
});
}

public VoyageView() {

  String[] locations = new String[]{"Bayonne", "Berlin", "Bern", "Bilbao", "Birmingham", "Bremen", "Brussels"};
  ListBox<String> departingCity = new ListBox<String>();
  departingCity.setItems(locations);
  ListBox<String> arrivingCity = new ListBox<String>();
  arrivingCity.setItems(locations);

  this.setLayout(new BorderLayout());
  FButton searchButton = new FButton("Search");
  FButton cancelButton = new FButton("Cancel");
  Panel citySelection = new Panel(new GridLayout(0,2));
  citySelection.add(departingCity);
  citySelection.add(arrivingCity);
  Panel buttonBar = new Panel();
  buttonBar.setLayout(new BoxLayout(buttonBar, BoxLayout.VERTICAL));
  buttonBar.add(searchButton);
  buttonBar.add(cancelButton);
  this.add(buttonBar, BorderLayout.WEST);
  this.add(citySelection, BorderLayout.CENTER);
  departingCity.addValueChangeListener(new HasValue.ValueChangeListener<HasValue.ValueChangeEvent<String>() {
    @Override
     public void valueChanged(HasValue.ValueChangeEvent<String> e) {
        if (arrivingCity.getValue() == null) return;
        if (arrivingCity.getValue().equals(departingCity.getValue())) {
             arrivingCity.setValue(null);
          }
     }
  });
}

Java swing code before (left) and after (right) migrating to Vaadin Flow
using the Modernization Toolkit. 

A good example of modernizing core apps built with Java Swing is how IZUM, a Slovenian institute, successfully modernized its library software. The original software, built with Java Swing, lacked mobile support and relied on outdated technology.

IZUM migrated the Swing application to Vaadin Flow, a framework compatible with Swing. This allowed the reuse of over 90% of existing code, significantly speeding up development. The new web application is mobile-friendly, accessible, and well-received by users. The successful migration, completed in just two years, demonstrates Vaadin Flow's capability to rapidly modernize Java Swing applications.

Java Swing no longer aligns with modern application development practices, and there is virtually no chance that Oracle will revive It. However, modernizing legacy Java Swing apps can often help companies stay competitive and deliver a better user experience.

We encourage you to explore Vaadin Flow as a powerful and efficient solution for modernizing your Java Swing applications. With its intuitive Java-based development model, extensive component library, and seamless integration capabilities, Vaadin Flow lets you build modern, scalable, and user-friendly web applications in a similar way to Java Swing.

Start planning your modernization journey today! To learn how our Migration Toolkit can help, request a free assessment.