The servlet-filterlistener quickstart demonstrates how to use Servlet filters and listeners in an application.

What is it?

The servlet-filterlistener quickstart demonstrates how to use Servlet filters and listeners in Red Hat JBoss Enterprise Application Platform.

This example contains the following classes:

  • FilterExampleServlet: A simple servlet that prints a form that contains an input field and a Send button.

  • VowelRemoverFilter: A servlet filter that removes the vowels from the text entered in the form.

  • ParameterDumpingRequestListener: A simple servlet request listener that creates a map of the original HTTP request parameter values before the filter is applied.

System Requirements

The application this project produces is designed to be run on Red Hat JBoss Enterprise Application Platform 7.1 or later.

All you need to build this project is Java 8.0 (Java SDK 1.8) or later and Maven 3.3.1 or later. See Configure Maven to Build and Deploy the Quickstarts to make sure you are configured correctly for testing the quickstarts.

Use of EAP_HOME

In the following instructions, replace EAP_HOME with the actual path to your JBoss EAP installation. The installation path is described in detail here: Use of EAP_HOME and JBOSS_HOME Variables.

Start the JBoss EAP Standalone Server

  1. Open a terminal and navigate to the root of the JBoss EAP directory.

  2. Start the JBoss EAP server with the default profile by typing the following command.

    $ EAP_HOME/bin/standalone.sh 
    Note
    For Windows, use the EAP_HOME\bin\standalone.bat script.

Build and Deploy the Quickstart

  1. Make sure you start the JBoss EAP server as described above.

  2. Open a terminal and navigate to the root directory of this quickstart.

  3. Type the following command to build the artifacts.

    $ mvn clean package wildfly:deploy

This deploys the servlet-filterlistener/target/servlet-filterlistener.war to the running instance of the server.

You should see a message in the server log indicating that the archive deployed successfully.

Access the Application

The application will be running at the following URL http://localhost:8080/servlet-filterlistener/.

You are presented with a form containing an input field and a Send button. To test the quickstart:

  1. Enter some text in the field, for example:

    This is only a test!
  2. Click Send.

  3. The servlet filter intercepts and removes the vowels from the text entered in the form and displays:

    You Typed: Ths s nly tst!
  4. The server console displays the following log messages.

    The following messages appear in the log when you access the application URL. This is because the ParameterDumpingRequestListener, which is a ServletRequestListener, and the VowelRemoverFilter both map to the application context and print logs for every request. Note that the VowelRemoveFilter contains logic to handle empty input field arguments.

    INFO  [io.undertow.servlet] (default task-46) ParameterDumpingRequestListener: request has been initialized. It has 0 parameters:
    INFO  [io.undertow.servlet] (default task-46) VowelRemoverFilter initialized
    INFO  [io.undertow.servlet] (default task-46) VowelRemoverFilter invoking filter chain...
    INFO  [io.undertow.servlet] (default task-46) VowelRemoverFilter done filtering request
    INFO  [io.undertow.servlet] (default task-46) ParameterDumpingRequestListener: request has been destroyed
    INFO  [io.undertow.servlet] (default task-48) ParameterDumpingRequestListener: request has been initialized. It has 0 parameters:
    INFO  [io.undertow.servlet] (default task-48) VowelRemoverFilter invoking filter chain...
    INFO  [io.undertow.servlet] (default task-48) VowelRemoverFilter done filtering request
    INFO  [io.undertow.servlet] (default task-48) ParameterDumpingRequestListener: request has been destroyed

    The following messages appear in the log when you type "This is only a test!" in the input field and click Send.

    INFO  [io.undertow.servlet] (default task-50) ParameterDumpingRequestListener: request has been initialized. It has 1 parameters:
    INFO  [io.undertow.servlet] (default task-50)   userInput=This is only a test!
    INFO  [io.undertow.servlet] (default task-50) VowelRemoverFilter invoking filter chain...
    INFO  [io.undertow.servlet] (default task-50) VowelRemoverFilter done filtering request
    INFO  [io.undertow.servlet] (default task-50) ParameterDumpingRequestListener: request has been destroyed

Undeploy the Quickstart

When you are finished testing the quickstart, follow these steps to undeploy the archive.

  1. Make sure you start the JBoss EAP server as described above.

  2. Open a terminal and navigate to the root directory of this quickstart.

  3. Type this command to undeploy the archive:

    $ mvn wildfly:undeploy

Run the Quickstart in Red Hat JBoss Developer Studio or Eclipse

You can also start the server and deploy the quickstarts or run the Arquillian tests in Red Hat JBoss Developer Studio or from Eclipse using JBoss tools. For general information about how to import a quickstart, add a JBoss EAP server, and build and deploy a quickstart, see Use JBoss Developer Studio or Eclipse to Run the Quickstarts.

Deploy the Quickstart to OpenShift Online

Use these instructions to deploy the quickstart to Red Hat OpenShift Online. If you do not yet have an OpenShift Online account and are interested in signing up for one, see Choose a Plan in the OpenShift Online documentation located on the Red Hat Customer Portal. For information about running JBoss EAP on Red Hat OpenShift Online, see Getting Started with JBoss EAP for OpenShift Online, also located on the Red Hat Customer Portal.

Create and Deploy the Quickstart Project

Follow these instructions to deploy this quickstart to OpenShift Online.

  1. Browse to OpenShift Online console and login with your credentials.

  2. On the View All Projects or Welcome to Project page, click Create Project.

  3. On the Create Project page, enter the following information:

    Name:  servlet-filterlistener
    Display Name servlet-filterlistener
    Description: servlet-filterlistener
  4. Click Create to create the project.

  5. On the My Projects page, choose your new servlet-filterlistener and click Browse Catalog.

  6. Choose JBoss EAP CD (no https) and then click Next to view the Information page.

  7. Click Next to navigate to the Configuration page. . . Enter the following information. You can leave the remaining fields as they are.

    Add to Project: servlet-filterlistener
    Application Name: servlet-filterlistener
    Custom http Route Hostname: (leave blank)
    Git Repository URL: https://github.com/jboss-developer/jboss-eap-quickstarts/
    Git Reference: openshift
    Context directory: servlet-filterlistener
  8. Click the Create button.

  9. Click on the Continue to the project overview link.

    • You should see "Build #1 is running …​" with the console log below.

      Cloning ...
      Downloading ...
      Building ...
      Copying ...
      Pushing ...
    • At the end of the build, you should see "Push successful".

    • Click View Full Log to see the entire log.

  10. Click the Overview tab to see the servlet-filterlistener deployment.

  11. Click on the application URL on the right side of the page to view the running application. It should be in the following pattern:

    http://APPLICATION_NAME-PROJECT_NAME.PORT.HOST.openshiftapps.com

Delete the Quickstart Project

Follow these instructions to delete the project from OpenShift Online.

  1. Go to the View All Projects page and select Delete Project from the drop down list to the right of the servlet-filterlistener project.

  2. Type the name of the project to confirm, and then click Delete

Debug the Application

If you want to debug the source code of any library in the project, run the following command to pull the source into your local repository. The IDE should then detect it.

$ mvn dependency:sources