moelholm/example-jpa-servlet

JPA and Servlet Example

This example uses JPA and Servlet classes deployed through a user-provided main() programmatically without constructing a .war file during the build.

Please raise any issues found with this example on the main project: https://github.com/wildfly-swarm/wildfly-swarm/issues

Project pom.xml

This project is a normal maven project with jar packaging, not war.

<packaging>jar</packaging>

The project adds a <plugin> to configure wildfly-swarm-plugin to create the runnable .jar.

<plugin>
  <groupId>org.wildfly.swarm</groupId>
  <artifactId>wildfly-swarm-plugin</artifactId>
  <version>${version.wildfly-swarm}</version>
  <configuration>
    <mainClass>org.wildfly.swarm.examples.jpa.Main</mainClass>
  </configuration>
  <executions>
    <execution>
      <goals>
        <goal>package</goal>
      </goals>
    </execution>
  </executions>
</plugin>

To define the needed parts of WildFly Swarm, a few dependencies are added

<dependency>
    <groupId>org.wildfly.swarm</groupId>
    <artifactId>wildfly-swarm-jpa</artifactId>
    <version>${version.wildfly-swarm}</version>
</dependency>
<dependency>
    <groupId>org.wildfly.swarm</groupId>
    <artifactId>wildfly-swarm-undertow</artifactId>
    <version>${version.wildfly-swarm}</version>
</dependency>

The wildfly-swarm-jpa dependency allows usage of ShrinkWrap APIs within the main(), provides configuration classes for adding the JDBC driver and datasources to the container, in addition to providing the JPA APIs. The wildfly-swarm-undertow provides the Servlet APIs.

Additionally, the JDBC driver jar you wish to deploy is specified as a dependency within your pom.xml

<dependency>
    <groupId>com.h2database</groupId>
    <artifactId>h2</artifactId>
    <version>1.4.187</version>
</dependency>

Project main()

Since this project deploys Servlet resources without a .war being constructed, it provides its own main() method (specified above via the wildfly-swarm-plugin) to configure the container and deploy the resources programmatically. Additionally, it deploys the JDBC driver jar using a simplified Maven GAV (no version is required) and deploys a datasource.

package org.wildfly.swarm.examples.jpa;

import org.jboss.shrinkwrap.api.asset.ClassLoaderAsset;
import org.wildfly.swarm.container.Container;
import org.wildfly.swarm.container.DefaultWarDeployment;
import org.wildfly.swarm.container.WarDeployment;
import org.wildfly.swarm.datasources.Datasource;
import org.wildfly.swarm.datasources.DatasourceDeployment;
import org.wildfly.swarm.datasources.DriverDeployment;

public class Main {
    public static void main(String[] args) throws Exception {
        Container container = new Container();
        container.start();

        DriverDeployment driverDeployment = new DriverDeployment(container, "com.h2database:h2", "h2");
        container.deploy(driverDeployment);

        DatasourceDeployment dsDeployment = new DatasourceDeployment(container, new Datasource("ExampleDS")
                .connectionURL("jdbc:h2:mem:test;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=FALSE")
                .driver("h2")
                .authentication("sa", "sa")
        );
        container.deploy(dsDeployment);

        WarDeployment deployment = new DefaultWarDeployment(container);
        deployment.getArchive().addClasses(Employee.class);
        deployment.getArchive().addClass(EmployeeServlet.class);
        deployment.getArchive().addAsWebInfResource(new ClassLoaderAsset("META-INF/persistence.xml", Main.class.getClassLoader()), "classes/META-INF/persistence.xml");
        deployment.getArchive().addAsWebInfResource(new ClassLoaderAsset("META-INF/load.sql", Main.class.getClassLoader()), "classes/META-INF/load.sql");

        container.deploy(deployment);
    }
}

This method constructs a new default Container, which automatically initializes all fractions (or subsystems) that are available.

A DriverDeployment is created, specifying the groupId and artifactId portions of the maven dependency (the version is inferred from your pom.xml), along with a name for referencing the driver.

A datasource is then deployed using the previously-deployed driver.

JNDI names are bound automatically.

A DefaultWarDeployment is constructed, and the JPA Entity class, Servlet class, persistence.xml and load.sql files are added to it.

Run

You can run it many ways:

• mvn package && java -jar ./target/wildfly-swarm-example-jaxrs-servlet-1.0.0.Beta1-SNAPSHOT-swarm.jar
• mvn wildfly-swarm:run
• In your IDE run the org.wildfly.swarm.examples.jpa.Main class

Use

http://localhost:8080/