Running and Testing Hazelcast in a Spring Boot Application

The folks over at OpenCredo recently published a blog post entitled, "Running and Testing Hazelcast in a Spring Boot Application." In the post, they introduce some of the basic features of Hazelcast, some of its limitations, how to embed it in a Spring Boot application and write integration testings. Here's how to start a Hazelcast instance in a Spring Boot application. 

Hazelcast in a Spring Boot Application

Starting a Hazelcast instance in a Spring Boot application is easy:

1. Include the com.hazelcast:hazelcast dependency
2. Initialise a com.hazelcast.config.Config Spring bean

The following example uses Spring Boot 1.3.0. This provides Hazelcast 3.5.3 as managed dependency.

pom.xml

…
<parent>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-parent</artifactId>
 <version>1.3.0.RELEASE</version>
 <relativePath/>
</parent>
 …
<dependency>
 <groupId>com.hazelcast</groupId>
 <artifactId>hazelcast</artifactId>
 <!-- Version is managed by Spring Boot starter -->
</dependency>
…

Configuration

@Configuration
public class HazelcastConfiguration {
 @Bean
 public Config config() {
   return new Config(); // Set up any non-default config here
 }
}

Spring Boot automatically start a Hazelcast instance when it finds both:

1. Hazelcast in classpath
2. A com.hazelcast.config.Config bean.

On startup, an instance of com.hazelcast.core.HazelcastInstance is then added to the Spring Application Context.