Author: Jonathan Fuerth
Level: Intermediate
Technologies: Servlet Filter, Servlet Listener
Summary: The servlet-filterlistener
quickstart demonstrates how to use Servlet filters and listeners in an application.
Target Product: WildFly
Source: https://github.com/wildfly/quickstart/
The servlet-filterlistener
quickstart demonstrates how to use Servlet filters and listeners in WildFly Application Server.
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.The application this project produces is designed to be run on WildFly Application Server 11 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 for WildFly 11 to make sure you are configured correctly for testing the quickstarts.
In the following instructions, replace WILDFLY_HOME
with the actual path to your WildFly installation. The installation path is described in detail here: Use of WILDFLY_HOME and JBOSS_HOME Variables.
For Linux: WILDFLY_HOME/bin/standalone.sh
For Windows: WILDFLY_HOME\bin\standalone.bat
mvn clean install wildfly:deploy
This will deploy target/servlet-filterlistener.war
to the running instance of the server.
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:
This is only a test!
You Typed: Ths s nly tst!
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
mvn wildfly:undeploy
You can also start the server and deploy the quickstarts or run the Arquillian tests from Eclipse using JBoss tools. For general information about how to import a quickstart, add a WildFly server, and build and deploy a quickstart, see Use JBoss Developer Studio or Eclipse to Run the Quickstarts.
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