Helidon MP

Step 1: Have a Helidon MP project

You need a valid Helidon MicroProfile project. Create one from IntelliJ or from the Helidon project starter. A starter project already gives you the Helidon MP parent, the helidon-microprofile-core bundle, a META-INF/beans.xml, and a Jandex index — Mateu builds on top of that.

Step 2: Add Mateu dependencies

<dependency>
    <groupId>io.mateu</groupId>
    <artifactId>helidon-mp-core</artifactId>
    <version>3.0-alpha.289</version>
</dependency>
<!-- serves the built-in frontend; choose one: vaadin-lit, redwood -->
<dependency>
    <groupId>io.mateu</groupId>
    <artifactId>vaadin-lit</artifactId>
    <version>3.0-alpha.289</version>
</dependency>
<!-- REQUIRED: use Jackson (not JSON-B) for JAX-RS bodies. Mateu's wire model relies on
     Jackson @JsonTypeInfo "type" discriminators; Helidon's default JSON-B (Yasson) drops
     them and the frontend renders empty components. -->
<dependency>
    <groupId>org.glassfish.jersey.media</groupId>
    <artifactId>jersey-media-json-jackson</artifactId>
    <scope>runtime</scope>
</dependency>

helidon-mp-core already contributes the MateuService CDI bean, a Jackson ContextResolver<ObjectMapper>, and the request/bean-provider glue, so your application needs no Mateu wiring code.

Step 3: Configure the annotation processor

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <configuration>
                <parameters>true</parameters>
                <annotationProcessorPaths>
                    <path>
                        <groupId>io.mateu</groupId>
                        <artifactId>annotation-processor-helidon-mp</artifactId>
                        <version>3.0-alpha.289</version>
                    </path>
                    <!-- If your @UI classes live in a SEPARATE module, add that module here too
                         (compiled with the indexer AP) so its route registrations are read. -->
                </annotationProcessorPaths>
            </configuration>
        </plugin>
    </plugins>
</build>

Step 4: Serve the frontend assets

The frontend jar bundles its assets under /static/assets/* on the classpath and expects them at /assets/*. Map them in src/main/resources/META-INF/microprofile-config.properties:

# Serve the bundled Mateu frontend. Mount it under /assets ONLY — a context of "/"
# would shadow every JAX-RS route (the static handler is terminal).
server.static.classpath.context=/assets
server.static.classpath.location=/static/assets

Make sure src/main/resources/META-INF/beans.xml exists (a Helidon starter includes one) so Weld/Jersey discover the generated controllers:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="https://jakarta.ee/xml/ns/jakartaee"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="https://jakarta.ee/xml/ns/jakartaee
                           https://jakarta.ee/xml/ns/jakartaee/beans_4_0.xsd"
       version="4.0"
       bean-discovery-mode="annotated">
</beans>

Step 5: Create your Mateu UI

package com.example;

import io.mateu.uidl.annotations.UI;

@UI("")
public class HelloWorld {
}

Step 6: Run

mvn helidon:dev

Open http://localhost:8080 in your browser.

Next