Build a RESTful Web Service with Jakarta EE – Step‑by‑Step Guide

Set Up Development Environment

Install a Java Development Kit (JDK) 8 or higher (the example uses 8; testing can be done with 11 or 17). Install a Jakarta EE‑compatible application server. Install Maven 3+ (or use SDKMan).

Create a RESTful Web Service Project

Generate the project with the Jakarta EE Eclipse Starter, an IDE, or a Maven archetype. The following Maven command creates a minimal Jakarta EE 10 project:

mvn archetype:generate -DarchetypeGroupId=org.eclipse.starter -DarchetypeArtifactId=jakartaee10-minimal -DarchetypeVersion=1.1.0 -DgroupId=org.eclipse.rest -DartifactId=rest-service -Dprofile=web-api -Dversion=1.0.0-SNAPSHOT -DinteractiveMode=false

The command produces the following directory layout:

.
├─ pom.xml
└─ src
   ├─ main
   │  └─ java
   │     └─ org
   │        └─ eclipse
   │           └─ restfulservice
   │              ├─ ApplicationConfig.java
   │              └─ resources
   │                 ├─ HelloRecord.java
   │                 └─ RestResource.java
   ├─ resources
   │  └─ META-INF
   │     └─ beans.xml
   └─ webapp

RestResource.java

package org.eclipse.restfulservice.resources;

import jakarta.ws.rs.GET;
import jakarta.ws.rs.core.MediaType;
import jakarta.ws.rs.Path;
import jakarta.ws.rs.Produces;

@Path("hello")
public class RestResource {
    @GET
    @Produces(MediaType.APPLICATION_JSON)
    public HelloRecord hello() {
        return new HelloRecord("Hello from Jakarta EE");
    }
}

The @Path("hello") annotation binds the class to the URI /hello. @GET restricts handling to HTTP GET requests, and @Produces(MediaType.APPLICATION_JSON) tells Jakarta REST to serialize the returned object as JSON.

HelloRecord.java (record version)

package org.eclipse.restfulservice.resources;

public record HelloRecord(String text) {}

If you are on a Java version prior to 16, replace the record with a traditional POJO:

package org.eclipse.restfulservice.resources;

public final class HelloRecord {
    private final String text;
    public HelloRecord(String text) {
        this.text = text;
    }
    public String text() {
        return text;
    }
}

Run the Project from the CLI

The generated project does not include a runtime container, allowing you to choose any Jakarta EE‑compatible server. This guide uses WildFly.

Add the WildFly Maven plugin to pom.xml:

<plugin>
  <groupId>org.wildfly.plugins</groupId>
  <artifactId>wildfly-maven-plugin</artifactId>
  <version>2.1.0.Beta1</version>
  <executions>
    <execution>
      <phase>install</phase>
      <goals>
        <goal>deploy</goal>
      </goals>
    </execution>
  </executions>
</plugin>

The plugin deploys, redeploys, or runs Jakarta EE applications on WildFly. Build and start the server with: mvn clean package wildfly:run If WildFly is not installed locally, the plugin downloads and launches it, then deploys the generated WAR file.

Test the Service

With the server running, request the endpoint:

curl -v http://localhost:8080/restfulservice/hello

The response is the JSON payload:

{"text":"Hello from Jakarta EE"}

URL Structure Overview

http://<hostname>:<port>/<context-root>/<REST-config>/<resource-config>

Hostname : the machine on which WildFly is installed.

Port : HTTP port (default 8080, configurable).

Context‑root : the WAR file name without extension (default).

REST‑config : the value of @ApplicationPath (default “/”).

Resource‑config : the value of @Path on the resource class (e.g., “/hello”).

To change the REST base path, modify ApplicationConfig.java:

import jakarta.ws.rs.ApplicationPath;
import jakarta.ws.rs.core.Application;

@ApplicationPath("/api")
public class ApplicationConfig extends Application {}

After rebuilding and restarting, the endpoint becomes http://localhost:8080/restfulservice/api/hello.