Microservices With Wildfly Swarm and Infinispan

Everybody loves microservices, right? Today, all of us has a slightly different understanding of what microservices are. However, among all of those different definitions and attributes, there's probably one thing that fits them all, and that is that they need to be simple.

So, let's have a look at some practical examples of creating a REST service with Infinispan as a storage wired together using CDI. We will be using Wildfly Swarm as a running platform.

Bootstrapping a New Project

A good way to start a new Wildfly Swarm project is to generate it. The only requirement here is that you add "JAX-RS with CDI" and "JPA" as dependencies.

The next step is to add the infinispan-embedded artifact. The final pom.xml should look like the following:

<?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/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>org.infinispan</groupId>
    <artifactId>wildfly-swarm-demo</artifactId>
    <version>1.0.0-SNAPSHOT</version>
    <packaging>war</packaging>
    <properties>
        <version.infinispan>8.2.4.Final</version.infinispan>
        <version.wildfly.swarm>2016.9</version.wildfly.swarm>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <failOnMissingWebXml>false</failOnMissingWebXml>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.wildfly.swarm</groupId>
                <artifactId>bom-all</artifactId>
                <version>${version.wildfly.swarm}</version>
                <scope>import</scope>
                <type>pom</type>
            </dependency>
            <dependency>
              <groupId>org.infinispan</groupId>
                <artifactId>infinispan-bom</artifactId>
                <version>${version.infinispan}</version>
                <scope>import</scope>
                <type>pom</type>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <build>
        <finalName>wildfly-swarm-demo</finalName>
        <plugins>
            <plugin>
                <groupId>org.wildfly.swarm</groupId>
                <artifactId>wildfly-swarm-plugin</artifactId>
                <version>${version.wildfly.swarm}</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>package</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
    <dependencies>
        <!-- Java EE 7 dependency -->
        <dependency>
            <groupId>javax</groupId>
            <artifactId>javaee-web-api</artifactId>
            <version>7.0</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.infinispan</groupId>
            <artifactId>infinispan-embedded</artifactId>
        </dependency>
        <dependency>
            <groupId>javax.cache</groupId>
            <artifactId>cache-api</artifactId>
        </dependency>
        <dependency>
            <groupId>org.wildfly.swarm</groupId>
            <artifactId>jaxrs-cdi</artifactId>
        </dependency>
        <dependency>
            <groupId>org.wildfly.swarm</groupId>
            <artifactId>jpa</artifactId>
        </dependency>
    </dependencies>
</project>

Next, the Infinispan CDI Extension will take care of bootstrapping Infinispan. This means that we can dive directly into JAX-RS code. It should look like the following:

package com.example.configuration;
import javax.ws.rs.ApplicationPath;
import javax.ws.rs.core.Application;
@ApplicationPath("/rest")
public class RESTConfiguration extends Application {
}

package com.example.rest;
import javax.inject.Inject;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.core.Response;
import org.infinispan.Cache;
@Path("/infinispan")
public class InfinispanEndpoint {
   @Inject
  Cache<String, String> cache;
   @GET
   @Path("cache")
   public Response printContent() {
      return Response.ok(cache.keySet().toString()).build();
   }
   @POST
   @Path("cache")
   public Response addSomethingToTheCache(String text) {
      cache.put(text, text);
      return Response.created(null).build();
   }
}

And that's it!

What's Next?

If you would like to have a look at the complete example, then you should check out my repository. The code is based on a fresh build from Infinispan master branch that contains a lot of improvements for CDI. You might build it yourself or just wait for 9.0.0.Beta1.