# cdi-veto: A Simple CDI Portable Extension Example

Author: Jason Porter
Level: Intermediate
Technologies: CDI
Summary: The `cdi-veto` quickstart is a simple CDI Portable Extension that uses SPI classes to show how to remove beans and inject JPA entities into an application.
Target Product: WildFly
Source: https://github.com/wildfly/quickstart/

## What is it?

The `cdi-veto` quickstart demonstrates a simple CDI portable extension and some of the SPI classes used to complete that task in an application deployed to WildFly Application Server. This particular extension explores the `ProcessInjectionTarget` and `InjectionTarget` SPI classes of CDI to demonstrate removing a bean from CDI's knowledge and correctly injecting JPA entities in your application.

A portable extension is an extension to Java EE 6 and above, which is tailored to a specific use case and will run on any Java EE 6 or later implementation. Portable extensions can implement features not yet supported by the specifications, such as type-safe messages or external configuration of beans.

The project contains very simple domain model classes, an extension class, the service provider configuration file, and an Arquillian test to verify the extension is working correctly.

This quickstart does not contain any user interface. The tests must be run to verify everything is working correctly.

Note: This quickstart uses the H2 database included with WildFly Application Server 11. It is a lightweight, relational example datasource that is used for examples only. It is not robust or scalable, is not supported, and should NOT be used in a production environment!

Note: This quickstart uses a `*-ds.xml` datasource configuration file for convenience and ease of database configuration. These files are deprecated in WildFly and should not be used in a production environment. Instead, you should configure the datasource using the Management CLI or Management Console. Datasource configuration is documented in the Configuration Guide for WildFly Application Server.

## System Requirements

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.

## Use of WILDFLY_HOME

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.

## Start the Server

1. Open a command prompt and navigate to the root of the WildFly directory.
2. The following shows the command line to start the server:

       For Linux:   WILDFLY_HOME/bin/standalone.sh
       For Windows: WILDFLY_HOME\bin\standalone.bat

## Run the Arquillian Tests

This quickstart provides Arquillian tests. By default, these tests are configured to be skipped as Arquillian tests require the use of a container.

1. Make sure you have started the WildFly server as described above.
2. Open a command prompt and navigate to the root directory of this quickstart.
3. Type the following command to run the test goal with the following profile activated:

       mvn clean verify -Parq-remote

You can also let Arquillian manage the WildFly server by using the `arq-managed` profile. For more information about how to run the Arquillian tests, see Run the Arquillian Tests.

## Investigate the Console Output

Maven prints summary of the 4 performed tests to the console.

    -------------------------------------------------------
     T E S T S
    -------------------------------------------------------
    Running org.jboss.as.quickstart.cdi.veto.test.InjectionWithoutVetoExtensionWithManagerTest
    Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 1.492 sec
    Running org.jboss.as.quickstart.cdi.veto.test.InjectionWithVetoExtensionAndManagerTest
    Tests run: 2, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 7.988 sec
    Running org.jboss.as.quickstart.cdi.veto.test.InjectionWithVetoExtensionWithoutManagerTest
    Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 3.093 sec

    Results :

    Tests run: 4, Failures: 0, Errors: 0, Skipped: 0

In the server log you see a few lines similar to

             INFO  [VetoExtension] (MSC service thread 1-8) Vetoed class class org.jboss.as.quickstart.cdi.veto.model.Car
             INFO  [CarManager] (http--127.0.0.1-8080-2) Returning new instance of Car

That will let you know the extension is working. To really see what is going on and understand this example, please read the source and the tests.

## Server Log: Expected Warnings and Errors

Note: You will see the following warnings in the server log. You can ignore these warnings.

    WFLYJCA0091: -ds.xml file deployments are deprecated. Support may be removed in a future version.

    HHH000431: Unable to determine H2 database version, certain features may not work

## 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 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.

## 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