JSF Example with Eclipse and Tomcat

Date: 2017-04-27

Building Your First JSF Application: A Step-by-Step Guide

This article provides a comprehensive, plain-English explanation of setting up and running a basic JavaServer Faces (JSF) application using Eclipse and Tomcat. JSF is a powerful framework that simplifies the creation of user interfaces for server-side applications. It achieves this by providing reusable UI components, streamlining the development process and making web applications easier to build and maintain.

Understanding JSF and its Architecture

JSF, at its core, is a Model-View-Controller (MVC) framework. This architectural pattern separates an application into three interconnected parts: the Model (data and business logic), the View (user interface), and the Controller (handling user input and updating the model). JSF excels at managing the View and Controller aspects, simplifying the creation of dynamic web pages that interact seamlessly with the underlying data. It uses a component-based approach, allowing developers to assemble user interfaces from pre-built, reusable components like buttons, text fields, and more complex elements. These components handle much of the low-level interaction details, abstracting away complexities from the developer.

Setting Up the Development Environment

The instructions detail using Eclipse Kepler SR2 as the Integrated Development Environment (IDE), JDK 8 (or JDK 1.7, which is also compatible) as the Java Development Kit, and Tomcat 7 as the application server. These are all readily available, free tools that make up a standard Java web development environment. The IDE provides a structured environment for code writing, debugging, and deployment. The JDK provides the necessary tools and libraries to compile and run Java code, while Tomcat acts as the server that hosts and executes the web application.

Creating the JSF Project in Eclipse

The process begins by creating a new Dynamic Web Project within Eclipse. This involves a series of steps within the Eclipse interface, each guiding the user through the creation of the project and configuring the necessary settings. One crucial step is to incorporate JSF capabilities into the project. This involves downloading the JSF 2.2 Mojarra implementation. This implementation provides the necessary libraries and components required for using JSF features within the project. The process involves selecting the library from a list of available options and confirming the download to integrate it into the project’s structure. Once downloaded and installed, this completes the integration of JSF in your project.

Project Structure and File Creation

The project is structured in a standard web application layout, including the WebContent folder which contains the actual web pages. Two key files, hello-world.xhtml and myresponse.xhtml, are created. These files use XHTML, an XML-based markup language suitable for creating web pages, which is a recommended standard in JSF 2.0 applications. These files constitute the view portion of the MVC architecture.

Configuring the XHTML Files

The hello-world.xhtml file serves as the input page where the user interacts with the application. This page contains a simple form with a text field for user input and a submit button. The code within this page uses JSF expressions (denoted by #{…}) to bind the input value to a variable. This variable will later be used to display the response on the next page. Importantly, namespace declarations are added at the top of this XHTML file. These declarations specify the JSF component libraries to be used, allowing the use of JSF tags in the page.

The myresponse.xhtml file acts as the output page, displaying the result. It contains JSF expressions that display the value of the variable that receives the user input from the previous page. The action attribute of the button in the input page determines the page where the output is shown.

Deploying and Running the Application

Once the project is set up and the XHTML files are created and configured, the application is ready for deployment to Tomcat. The process involves right-clicking on the project in the Eclipse IDE and selecting the option to run the application on the server. Eclipse handles the deployment process, copying the necessary files to the Tomcat webapps directory and initiating the application.

Testing the Application

After deploying, the application can be accessed through a web browser using a URL that includes the application context and path to the initial XHTML page. This page presents the form to the user, allowing them to enter text. Upon submission, the text is processed and the myresponse.xhtml page is shown, displaying the entered text. This demonstrates a simple JSF application flow.

Troubleshooting Common Issues

The article also addresses some potential issues encountered during setup and execution. One common issue is an empty download provider list when attempting to acquire the necessary JSF libraries. Another issue discussed is the jsessionid error, which often relates to misconfigurations in the server setup or application deployment. These potential issues highlight the importance of correctly configuring the development environment and verifying the steps outlined for setting up the JSF application.

Conclusion

This comprehensive guide illustrates the process of creating a basic JSF application, emphasizing the conceptual understanding rather than specific code details. It details the setup of the development environment, the creation of the project, the use of JSF components in XHTML pages, and the deployment and execution of the application. It also highlights potential pitfalls and troubleshooting steps, providing a complete overview of the basic JSF development process. The focus remains on the fundamental concepts and principles, providing a solid foundation for anyone starting their journey with JavaServer Faces.

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