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This project is maintained by piranhacloud
If you are looking to create a simple Hello World web application with Piranha Micro to get started then you have come to the right place!
In 6 steps you will learn how to create the web application. They are:
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.micro</groupId>
<artifactId>helloworld</artifactId>
<version>1-SNAPSHOT</version>
<packaging>war</packaging>
<name>Piranha Micro - Create a Hello World application</name>
<properties>
<piranha.distribution>micro</piranha.distribution>
<piranha.version>23.9.0</piranha.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<build>
<finalName>piranha-micro-helloworld</finalName>
<plugins>
<plugin>
<groupId>cloud.piranha.maven.plugins</groupId>
<artifactId>piranha-maven-plugin</artifactId>
<version>${piranha.version}</version>
<executions>
<execution>
<id>pre-integration-test</id>
<phase>pre-integration-test</phase>
<goals>
<goal>start</goal>
</goals>
</execution>
<execution>
<id>post-integration-test</id>
<phase>post-integration-test</phase>
<goals>
<goal>stop</goal>
</goals>
</execution>
</executions>
<configuration>
<distribution>${piranha.distribution}</distribution>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.10.1</version>
<configuration>
<release>17</release>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-failsafe-plugin</artifactId>
<version>3.0.0-M7</version>
<executions>
<execution>
<goals>
<goal>integration-test</goal>
<goal>verify</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>3.3.2</version>
<configuration>
<failOnMissingWebXml>false</failOnMissingWebXml>
</configuration>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>jakarta.platform</groupId>
<artifactId>jakarta.jakartaee-web-api</artifactId>
<version>10.0.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.junit.jupiter</groupId>
<artifactId>junit-jupiter</artifactId>
<version>5.9.1</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>
Add the HelloWorldServlet.java file in the src/main/java/helloworld directory.
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()) {
response.setContentType("text/plain");
writer.println("Hello World!");
writer.flush();
}
}
}
Add the web.xml file to the src/main/webapp/WEB-INF directory.
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="4.0" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd">
<servlet>
<servlet-name>HelloWorldServlet</servlet-name>
<servlet-class>helloworld.HelloWorldServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>HelloWorldServlet</servlet-name>
<url-pattern>/index.html</url-pattern>
</servlet-mapping>
<session-config>
<session-timeout>30</session-timeout>
</session-config>
</web-app>
As we want to make sure the application gets tested before we release an integration test is added which will be executed as part of the build.
We’ll add the integration test to the src/test/java directory.
package helloworld;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.net.http.HttpResponse.BodyHandlers;
import static org.junit.jupiter.api.Assertions.assertTrue;
import org.junit.jupiter.api.Test;
class HelloWorldIT {
@Test
void testHelloWorldHtml() throws Exception {
HttpClient client = HttpClient.newHttpClient();
HttpRequest request = HttpRequest
.newBuilder(new URI("http://localhost:8080/helloworld/helloworld.html"))
.build();
HttpResponse<String> response = client.send(request, BodyHandlers.ofString());
assertTrue(response.body().contains("Hello World!"));
}
}
The application is setup to use JUnit to do integration testing using the Piranha Maven plugin so when you are building the application it will also execute an integration test validating the web application works.
To build and test the application execute the following command:
mvn install
To deploy your application you will need 2 pieces.
For the Piranha Servlet distribution zip go to Maven Central.
For the WAR file see the target directory.
Once you have downloaded the Piranha Server distribution zip extract it into
an empty directory and then copy the WAR file in the webapps directory.
From the bin directory of Piranha Server start the server using the command line below:
./start.sh
As you can see getting started with Piranha Server is straightforward!