Chapter 3. Creating an Eclipse Vert.x project with a POM file
When you develop a basic Eclipse Vert.x application, you should create the following artifacts. We will create these artifacts in our first getting-started
Eclipse Vert.x project.
- A Java class containing Eclipse Vert.x methods.
-
A
pom.xml
file containing information required by Maven to build the application.
The following procedure creates a simple Greeting
application that returns Greetings! as response.
Eclipse Vert.x supports builder images based on OpenJDK 8 and OpenJDK 11 for building and deploying your applications to OpenShift. Oracle JDK and OpenJDK 9 builder images are not supported.
Prerequisites
- OpenJDK 8 or OpenJDK 11 is installed.
- Maven is installed.
Procedure
Create a new directory
getting-started
, and navigate to it.$ mkdir getting-started $ cd getting-started
This is the root directory for the application.
Create a directory structure
src/main/java/com/example/
in the root directory, and navigate to it.$ mkdir -p src/main/java/com/example/ $ cd src/main/java/com/example/
Create a Java class file
MyApp.java
containing the application code.package com.example; import io.vertx.core.AbstractVerticle; import io.vertx.core.Promise; public class MyApp extends AbstractVerticle { @Override public void start(Promise<Void> promise) { vertx .createHttpServer() .requestHandler(r -> r.response().end("Greetings!")) .listen(8080, result -> { if (result.succeeded()) { promise.complete(); } else { promise.fail(result.cause()); } }); } }
The application starts an HTTP Server on port 8080. When you send a request, it returns Greetings! message.
Create a
pom.xml
file in the application root directorygetting-started
with the following content:-
In the
<dependencyManagement>
section, add theio.vertx:vertx-dependencies
artifact. -
Specify the
type
aspom
andscope
asimport
. In the
<project>
section, under<properties>
, specify the versions of Eclipse Vert.x and the Eclipse Vert.x Maven Plugin.NoteProperties can be used to set values that change in every release. For example, versions of product or plugins.
-
In the
<project>
section, under<plugin>
, specifyvertx-maven-plugin
. The Eclipse Vert.x Maven Plugin is used to package your application. Include
repositories
andpluginRepositories
to specify the repositories that contain the artifacts and plugins to build your application.The
pom.xml
contains the following artifacts:
<?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/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.example</groupId> <artifactId>my-app</artifactId> <version>1.0.0-SNAPSHOT</version> <packaging>jar</packaging> <name>My Application</name> <description>Example application using Vert.x</description> <properties> <vertx.version>4.1.8.redhat-00003</vertx.version> <vertx-maven-plugin.version>1.0.24</vertx-maven-plugin.version> <vertx.verticle>com.example.MyApp</vertx.verticle> <maven.compiler.source>1.8</maven.compiler.source> <maven.compiler.target>1.8</maven.compiler.target> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> </properties> <!-- Import dependencies from the Vert.x BOM. --> <dependencyManagement> <dependencies> <dependency> <groupId>io.vertx</groupId> <artifactId>vertx-dependencies</artifactId> <version>${vertx.version}</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <!-- Specify the Vert.x artifacts that your application depends on. --> <dependencies> <dependency> <groupId>io.vertx</groupId> <artifactId>vertx-core</artifactId> </dependency> <dependency> <groupId>io.vertx</groupId> <artifactId>vertx-web</artifactId> </dependency> <!-- Test dependencies --> <dependency> <groupId>io.vertx</groupId> <artifactId>vertx-junit5</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.junit.jupiter</groupId> <artifactId>junit-jupiter-engine</artifactId> <version>5.4.0</version> <scope>test</scope> </dependency> </dependencies> <!-- Specify the repositories containing Vert.x artifacts. --> <repositories> <repository> <id>redhat-ga</id> <name>Red Hat GA Repository</name> <url>https://maven.repository.redhat.com/ga/</url> </repository> </repositories> <!-- Specify the version of the Maven Surefire plugin. --> <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-surefire-plugin</artifactId> <version>3.0.0-M5</version> </plugin> <plugin> <!-- Configure your application to be packaged using the Vert.x Maven Plugin. --> <groupId>io.reactiverse</groupId> <artifactId>vertx-maven-plugin</artifactId> <version>${vertx-maven-plugin.version}</version> <executions> <execution> <id>vmp</id> <goals> <goal>initialize</goal> <goal>package</goal> </goals> </execution> </executions> </plugin> </plugins> </build> </project>
-
In the
Build the application using Maven from the root directory of the application.
mvn vertx:run
Verify that the application is running.
Use
curl
or your browser to verify if your application is running athttp://localhost:8080
and returns "Greetings!" as response.$ curl http://localhost:8080 Greetings!