💭 How I became a FullStack Java developer with Vaadin?

tags: blog, java, vaadin

What is Vaadin?

Vaadin is an open-source framework for building modern web applications. It allows developers to create rich, interactive user interfaces using Java, without the need to learn JavaScript or any other client-side programming language.

Vaadin was first released in 2002 and has since become a popular choice for building enterprise-level applications. It is used by companies such as Nokia, Goldman Sachs, and the United States Air Force, among others.

Why use Vaadin?

There are several reasons why Vaadin might be a good choice for your web application development needs.

First and foremost, Vaadin allows developers to build web applications using a language that they are already familiar with: Java. This means that developers who are proficient in Java can start building web applications without needing to learn a new programming language.

Vaadin also has a large community of developers who contribute to the framework and offer support. This means that if you run into any issues while using Vaadin, you are likely to find a solution through the community forums or by reaching out to other developers.

Vaadin also offers a number of built-in features that can help speed up development. These include a visual designer for building user interfaces, a set of pre-designed UI components, and support for data binding and validation.

Another advantage of Vaadin is that it is highly customizable. You can create custom UI components and themes, and integrate with other Java libraries and frameworks.

Getting started with Vaadin

To start building web applications with Vaadin, you will need to have the following software installed on your computer:

Java JDK 8 or newer
Apache Maven
An IDE (Integrated Development Environment) such as Eclipse or IntelliJ IDEA

Once you have these tools installed, you can start building your first Vaadin application.

First, create a new Maven project in your IDE. In the project's pom.xml file, you will need to add the following dependencies:

<dependencies>
    <dependency>
        <groupId>com.vaadin</groupId>
        <artifactId>vaadin-bom</artifactId>
        <version>14.4.1</version>
        <type>pom</type>
        <scope>import</scope>
    </dependency>
    <dependency>
        <groupId>com.vaadin</groupId>
        <artifactId>vaadin-server</artifactId>
    </dependency>
</dependencies>

Finally, create a servlet that maps to your UI class. This can be done by creating a new Java class that extends the com.vaadin.flow.server.VaadinServlet class and adding the following annotation:

@WebServlet(urlPatterns = "/*", name = "MyUIServlet", asyncSupported = true)
@VaadinServletConfiguration(ui = MyUI.class, productionMode = false)
public class MyUIServlet extends VaadinServlet {
}

This servlet will map the / URL pattern to your UI class, and configure the servlet to run in development mode (productionMode = false).

To run your application, you can either use the built-in Jetty server that comes with Vaadin, or you can deploy your application to an external servlet container such as Tomcat.

To run the application using the built-in Jetty server, you can use the mvn jetty:run command from the command line. This will start the Jetty server and deploy your application. You can then access the application by navigating to http://localhost:8080 in your web browser.

To deploy the application to an external servlet container, you will need to create a WAR (Web ARchive) file and deploy it to the container. This can be done by running the mvn package command, which will create a WAR file in the target directory of your project. You can then deploy the WAR file to your servlet container by following the instructions for your specific container.

Building user interfaces with Vaadin

Vaadin provides a number of UI components that you can use to build your application's user interface. These include buttons, text fields, tables, and many others.

To add a component to your UI, you simply need to instantiate the component and add it to the UI using the add method. For example, to add a button to your UI:

Button button = new Button("Click me");
add(button);

You can also customize the appearance and behavior of UI components by setting their properties. For example, to set the text of a button:

button.setText("Click me");

Vaadin also provides a visual designer tool that allows you to design your UI using a drag-and-drop interface. This can be a convenient way to quickly build your UI without having to write code.

Data binding and validation

Vaadin provides support for data binding and validation, which can help you to manage the flow of data between your application and its user interface.

Data binding allows you to bind UI components to data sources, so that the component's value is automatically updated when the data source changes, and vice versa. This can be useful for keeping your UI in sync with your application's data model.

To bind a component to a data source, you can use the setValue and getValue methods. For example, to bind a text field to a string data source:

StringProperty dataSource = new StringProperty("Initial value");
TextField textField = new TextField();
textField.setValue(dataSource);

Vaadin also provides support for validation, which allows you to ensure that the data entered by the user is valid. You can define validation rules for UI components using the setErrorMessage and setInvalid methods. For example, to ensure that a text field contains a valid email address:

textField.setErrorMessage("Please enter a valid email address");
textField.setInvalid(!EmailValidator.isValid(textField.getValue()));

Vaadin also provides a number of built-in validators for common data types such as strings, numbers, and dates.

Integrating with other Java libraries and frameworks

Vaadin is built on top of the Java programming language, which means that you can easily integrate it with other Java libraries and frameworks.

For example, you can use Vaadin with the Spring framework to manage dependencies and configure your application. You can also use Vaadin with the Hibernate framework to manage database access and ORM (Object-Relational Mapping).

Vaadin also provides integrations with a number of other popular Java libraries and frameworks, such as Apache Commons, Apache Lucene, and Google Guice.

Conclusion

Vaadin is a powerful and flexible framework for building modern web applications using Java. It offers a large set of built-in features, a visual designer tool, and support for data binding and validation. It is also highly customizable and can be integrated with other Java libraries and frameworks.

If you are a Java developer looking to build web applications, Vaadin is definitely worth considering as a tool for your development needs.

➡️ Official documentation here: https://vaadin.com/docs/latest

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