MicroProfile Config using TomEE

Posted by Hayri Cicek on September 09, 2018

TomEE version 7.1.0 now supports MicroProfile and in this quick tutorial I will show you how to get started with MicroProfile Config using TomEE application server.

Tools You Will Need
Maven 3.3+
Your favorite IDE
JDK 1.8+
Git

Clone the TomEE Starter Project from Github

$ git clone https://github.com/cicekhayri/tomee-javaee-rest-starter-project.git

Now it's time to add some dependencies.
Open the project in your favorite IDE and add the following to the pom.xml

<dependency>
    <groupId>org.apache.geronimo.config</groupId>
    <artifactId>geronimo-config-impl</artifactId>
    <version>1.0</version>
</dependency>

We added Geronimo Config dependency and your pom.xml should look like this now :

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.kodnito</groupId>
    <artifactId>restapi</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>

    <properties>
        <tomee.version>7.1.0</tomee.version>
        <javaee.api>7.0</javaee.api>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <failOnMissingWebXml>false</failOnMissingWebXml>
        <maven.compiler.target>1.8</maven.compiler.target>
        <maven.compiler.source>1.8</maven.compiler.source>
    </properties>

    <dependencies>
        <dependency>
            <groupId>javax</groupId>
            <artifactId>javaee-api</artifactId>
            <version>${javaee.api}</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.apache.geronimo.config</groupId>
            <artifactId>geronimo-config-impl</artifactId>
            <version>1.0</version>
        </dependency>
    </dependencies>

    <build>
        <finalName>${project.artifactId}</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.tomee.maven</groupId>
                <artifactId>tomee-maven-plugin</artifactId>
                <version>${tomee.version}</version>
                <configuration>
                    <tomeeVersion>${tomee.version}</tomeeVersion>
                    <tomeeClassifier>plus</tomeeClassifier>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

In project directory run the following command to download the dependencies.

$ mvn install

MicroProfile Config
Inside src/com/resources/META-INF/ create microprofile-config.properties file and add the following :

application.server=TomEE
username=root
password=pass

Open HelloWorldEndpoint.java and update the file to look like this :

package com.kodnito.restapi.rest;

import java.util.HashMap;
import java.util.Map;
import javax.enterprise.context.RequestScoped;
import javax.inject.Inject;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
import org.eclipse.microprofile.config.Config;
import org.eclipse.microprofile.config.inject.ConfigProperty;

@RequestScoped
@Path("hello")
public class HelloWorldEndpoint {

    @Inject
    @ConfigProperty(name = "username", defaultValue = "admin")
    private String username;

    @Inject
    Config config;

    @GET
    @Produces(MediaType.APPLICATION_JSON)
    public Response doGet() {
        Map<String, Object> configProperties = new HashMap<>();

        configProperties.put("username", username);
        configProperties.put("password", config.getValue("password", String.class));
        configProperties.put("application.server", config.getValue("application.server", String.class));

        return Response.ok(configProperties).build();
    }
}

@Inject @ConfigProperty annotation is used for injecting a single configuration property and we supply a default value.
@Inject Config here we are injecting the configuration object and we use getValue() method to retrieve the configuration property.

Your final project structure should look like this :

tree .
.
├── pom.xml
└── src
    ├── main
    │   ├── java
    │   │   └── com
    │   │       └── kodnito
    │   │           └── restapi
    │   │               └── rest
    │   │                   ├── ApplicationConfig.java
    │   │                   └── HelloWorldEndpoint.java
    │   ├── resources
    │   │   └── META-INF
    │   │       └── microprofile-config.properties
    │   └── webapp
    │       └── WEB-INF
    │           └── beans.xml
    └── test
        └── java

Inside your project directory run the following command to start the TomEE server.

$ mvn clean package tomee:run

Now, enter http://localhost:8080/restapi/api/hello in browser's address bar and see the output.



Clone the final project from GitHub

$ git clone https://github.com/cicekhayri/tomee-microprofile-config.git

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