The servlet-filterlistener
quickstart demonstrates how to use Servlet filters and listeners in an application.
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 32 or later.
All you need to build this project is Java 11.0 (Java SDK 11) or later and Maven 3.6.0 or later. See Configure Maven to Build and Deploy the Quickstarts 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.
When you see the replaceable variable QUICKSTART_HOME, replace it with the path to the root directory of all of the quickstarts.
-
Open a terminal and navigate to the root of the WildFly directory.
-
Start the WildFly server with the default profile by typing the following command.
$ WILDFLY_HOME/bin/standalone.sh
NoteFor Windows, use the WILDFLY_HOME\bin\standalone.bat
script.
-
Make sure WildFly server is started.
-
Open a terminal and navigate to the root directory of this quickstart.
-
Type the following command to build the quickstart.
$ mvn clean package
-
Type the following command to deploy the quickstart.
$ mvn 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.
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:
-
Enter some text in the field, for example:
This is only a test!
-
Click Send.
-
The servlet filter intercepts and removes the vowels from the text entered in the form and displays:
You Typed: Ths s nly tst!
-
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
This quickstart includes integration tests, which are located under the src/test/
directory. The integration tests verify that the quickstart runs correctly when deployed on the server.
Follow these steps to run the integration tests.
-
Make sure WildFly server is started.
-
Make sure the quickstart is deployed.
-
Type the following command to run the
verify
goal with theintegration-testing
profile activated.$ mvn verify -Pintegration-testing
Instead of using a standard WildFly server distribution, you can alternatively provision a WildFly server to deploy and run the quickstart, by activating the Maven profile named provisioned-server
when building the quickstart:
$ mvn clean package -Pprovisioned-server
The provisioned WildFly server, with the quickstart deployed, can then be found in the target/server
directory, and its usage is similar to a standard server distribution, with the simplification that there is never the need to specify the server configuration to be started.
The server provisioning functionality is provided by the WildFly Maven Plugin, and you may find its configuration in the quickstart pom.xml
:
<profile>
<id>provisioned-server</id>
<build>
<plugins>
<plugin>
<groupId>org.wildfly.plugins</groupId>
<artifactId>wildfly-maven-plugin</artifactId>
<configuration>
<feature-packs>
<feature-pack>
<location>org.wildfly:wildfly-galleon-pack:${version.server}</location>
</feature-pack>
</feature-packs>
<layers>...</layers>
<!-- deploys the quickstart on root web context -->
<name>ROOT.war</name>
</configuration>
<executions>
<execution>
<goals>
<goal>package</goal>
</goals>
</execution>
</executions>
</plugin>
...
</plugins>
</build>
</profile>
Note
|
Since the plugin configuration above deploys quickstart on root web context of the provisioned server, the URL to access the application should not have the |
The integration tests included with this quickstart, which verify that the quickstart runs correctly, may also be run with a provisioned server.
Follow these steps to run the integration tests.
-
Make sure the server is provisioned.
$ mvn clean package -Pprovisioned-server
-
Start the WildFly provisioned server, this time using the WildFly Maven Plugin, which is recommended for testing due to simpler automation. The path to the provisioned server should be specified using the
jbossHome
system property.$ mvn wildfly:start -DjbossHome=target/server
-
Type the following command to run the
verify
goal with theintegration-testing
profile activated, and specifying the quickstart’s URL using theserver.host
system property, which for a provisioned server by default ishttp://localhost:8080
.$ mvn verify -Pintegration-testing -Dserver.host=http://localhost:8080
-
Shutdown the WildFly provisioned server, this time using the WildFly Maven Plugin too.
$ mvn wildfly:shutdown
On OpenShift, the S2I build with Apache Maven uses an openshift
Maven profile to provision a WildFly server, deploy and run the quickstart in OpenShift environment.
The server provisioning functionality is provided by the WildFly Maven Plugin, and you may find its configuration in the quickstart pom.xml
:
<profile>
<id>openshift</id>
<build>
<plugins>
<plugin>
<groupId>org.wildfly.plugins</groupId>
<artifactId>wildfly-maven-plugin</artifactId>
<configuration>
<feature-packs>
<feature-pack>
<location>org.wildfly:wildfly-galleon-pack:${version.server}</location>
</feature-pack>
<feature-pack>
<location>org.wildfly.cloud:wildfly-cloud-galleon-pack:${version.pack.cloud}</location>
</feature-pack>
</feature-packs>
<layers>...</layers>
<name>ROOT.war</name>
</configuration>
<executions>
<execution>
<goals>
<goal>package</goal>
</goals>
</execution>
</executions>
</plugin>
...
</plugins>
</build>
</profile>
You may note that unlike the provisioned-server
profile it uses the cloud feature pack which enables a configuration tuned for OpenShift environment.
This section contains the basic instructions to build and deploy this quickstart to WildFly for OpenShift or WildFly for OpenShift Online using Helm Charts.
-
You must be logged in OpenShift and have an
oc
client to connect to OpenShift -
Helm must be installed to deploy the backend on OpenShift.
Once you have installed Helm, you need to add the repository that provides Helm Charts for WildFly.
$ helm repo add wildfly https://docs.wildfly.org/wildfly-charts/
"wildfly" has been added to your repositories
$ helm search repo wildfly
NAME CHART VERSION APP VERSION DESCRIPTION
wildfly/wildfly ... ... Build and Deploy WildFly applications on OpenShift
wildfly/wildfly-common ... ... A library chart for WildFly-based applications
Log in to your OpenShift instance using the oc login
command.
The backend will be built and deployed on OpenShift with a Helm Chart for WildFly.
Navigate to the root directory of this quickstart and run the following command:
$ helm install servlet-filterlistener -f charts/helm.yaml wildfly/wildfly --wait --timeout=10m0s
NAME: servlet-filterlistener
...
STATUS: deployed
REVISION: 1
This command will return once the application has successfully deployed. In case of a timeout, you can check the status of the application with the following command in another terminal:
oc get deployment servlet-filterlistener
The Helm Chart for this quickstart contains all the information to build an image from the source code using S2I on Java 17:
build:
uri: https://github.com/wildfly/quickstart.git
ref: main
contextDir: servlet-filterlistener
deploy:
replicas: 2
This will create a new deployment on OpenShift and deploy the application.
If you want to see all the configuration elements to customize your deployment you can use the following command:
$ helm show readme wildfly/wildfly
Get the URL of the route to the deployment.
$ oc get route servlet-filterlistener -o jsonpath="{.spec.host}"
Access the application in your web browser using the displayed URL.
Note
|
The Maven profile named |
The integration tests included with this quickstart, which verify that the quickstart runs correctly, may also be run with the quickstart running on OpenShift.
Note
|
The integration tests expect a deployed application, so make sure you have deployed the quickstart on OpenShift before you begin. |
Run the integration tests using the following command to run the verify
goal with the integration-testing
profile activated and the proper URL:
$ mvn verify -Pintegration-testing -Dserver.host=https://$(oc get route servlet-filterlistener --template='{{ .spec.host }}')
Note
|
The tests are using SSL to connect to the quickstart running on OpenShift. So you need the certificates to be trusted by the machine the tests are run from. |