Create a Piranha Embedded JLink application
Can you create a JLink application with Piranha Embedded?
In 6 steps you will learn how to so. They are:
- Create the Maven POM file
- Add the application class
- Add the servlet class
- Add the module-info
- Build the application
- Run the application
Create the Maven POM file
Create an empty directory to store your Maven project. Inside of that directory create the pom.xml file with the content as below.
<?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>cloud.piranha.guides.embedded</groupId>
<artifactId>jlink</artifactId>
<version>24.10.0-SNAPSHOT</version>
<packaging>jar</packaging>
<name>Piranha Embedded - JLink application</name>
<properties>
<exec-maven-plugin.version>3.2.0</exec-maven-plugin.version>
<java.version>21</java.version>
<jrelease-maven-plugin.version>1.10.0</jrelease-maven-plugin.version>
<maven-compiler-plugin.version>3.12.1</maven-compiler-plugin.version>
<maven-dependency-plugin.version>3.6.1</maven-dependency-plugin.version>
<maven-jar-plugin.version>3.3.0</maven-jar-plugin.version>
<piranha.version>24.2.0</piranha.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<main.class>helloworld.HelloWorldApplication</main.class>
</properties>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>${maven-compiler-plugin.version}</version>
<configuration>
<release>${java.version}</release>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<version>${maven-dependency-plugin.version}</version>
<executions>
<execution>
<id>copy-dependencies</id>
<phase>prepare-package</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
<configuration>
<outputDirectory>${project.build.directory}/modules</outputDirectory>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<version>${exec-maven-plugin.version}</version>
<configuration>
<mainClass>${main.class}</mainClass>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>${maven-jar-plugin.version}</version>
<configuration>
<archive>
<manifest>
<mainClass>${main.class}</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
<plugin>
<groupId>org.jreleaser</groupId>
<artifactId>jreleaser-maven-plugin</artifactId>
<version>${jrelease-maven-plugin.version}</version>
<configuration>
<gitRootSearch>true</gitRootSearch>
<jreleaser>
<project>
<description>${project.name}</description>
<copyright>Manorrock.com</copyright>
</project>
<assemble>
<jlink>
<helloworld>
<active>ALWAYS</active>
<imageName>{{distributionName}}-{{projectVersion}}</imageName>
<java>
<mainModule>helloworld</mainModule>
<mainClass>${main.class}</mainClass>
</java>
<copyJars>true</copyJars>
<mainJar>
<path>${project.build.directory}/${project.artifactId}-${project.version}.jar</path>
</mainJar>
<jars>
<jar>
<pattern>${project.build.directory}/modules/*.jar</pattern>
</jar>
</jars>
</helloworld>
</jlink>
</assemble>
</jreleaser>
</configuration>
<executions>
<execution>
<id>assemble</id>
<phase>verify</phase>
<goals>
<goal>assemble</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>cloud.piranha</groupId>
<artifactId>piranha-embedded</artifactId>
<version>${piranha.version}</version>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>cloud.piranha.http</groupId>
<artifactId>piranha-http-impl</artifactId>
<version>${piranha.version}</version>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>cloud.piranha.http</groupId>
<artifactId>piranha-http-webapp</artifactId>
<version>${piranha.version}</version>
<scope>compile</scope>
</dependency>
</dependencies>
</project>
Add the application class
Add the HelloWorldApplication class in the src/main/java directory, which
allows you to configure the EmbeddedPiranha instance as well as the
DefaultHttpServer instance.
package helloworld;
import cloud.piranha.embedded.EmbeddedPiranha;
import cloud.piranha.embedded.EmbeddedPiranhaBuilder;
import cloud.piranha.http.impl.DefaultHttpServer;
import cloud.piranha.http.webapp.HttpWebApplicationServerProcessor;
public class HelloWorldApplication {
public static void main(String[] arguments) throws Exception {
EmbeddedPiranha piranha = new EmbeddedPiranhaBuilder()
.servlet("HelloWorld", HelloWorldServlet.class)
.servletMapping("HelloWorld", "/*")
.buildAndStart();
DefaultHttpServer server = new DefaultHttpServer(8080,
new HttpWebApplicationServerProcessor(piranha), false);
server.start();
}
}
Add the servlet
And we are adding a simple HelloWorld servlet.
package helloworld;
import java.io.IOException;
import java.io.PrintWriter;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
public class HelloWorldServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws IOException, ServletException {
try (PrintWriter writer = response.getWriter()) {
writer.println("Hello World");
writer.flush();
}
}
}
Add the module info
Now add the module-info.java to the src/main/java directory.
module helloworld {
exports helloworld;
requires cloud.piranha.embedded;
requires cloud.piranha.http.api;
requires cloud.piranha.http.impl;
requires cloud.piranha.http.webapp;
requires jakarta.servlet;
}
Build the application
The following command line will build your application:
mvn verify
Run the application
In the previous step you created the JLink custom image. To execute the
application go to the target/jreleaser directory and look for the bin
directory and execute the helloworld wrapper in it. And then point your
browser to http://localhost:8080 to see it in action.
Conclusion
As you can see creating a JLink runtime image with Piranha Embedded is a few easy steps away!