KumuluzEE

Lightweight open-source framework for developing microservices using standard Java EE technologies and migrating Java EE to cloud-native architecture.

KumuluzEE is a lightweight framework for developing microservices using standard Java EE technologies and migrating existing Java EE applications to microservices. KumuluzEE packages microservices as standalone JARs. KumuluzEE microservices are lightweight and optimized for size and start-up time. They fit perfectly with Docker containers. KumuluzEE microservices are fully compatible with Kubernetes.

KumuluzEE also provides extensions for developing common patterns in cloud-native architectures, including configuration, logging, discovery, fault tolerance with circuit-breakers, metrics, security, event streaming and more.

KumuluzEE has been designed to use the standard Java EE technologies and APIs with optional extensions for easier development of cloud-native microservices. Therefore, it is particularly suitable for existing enterprise Java EE developers, who would like to leverage their skills, but progressively move from monolithic to microservice design patterns.

KumuluzEE is Eclipse MicroProfile compliant and provides support for MicroProfile 1.0, 1.1 and 1.2. It implements MicroProfile Config 1.1, MicroProfile Health 1.0, MicroProfile Fault Tolerance 1.0, MicroProfile Metrics 1.0 and MicroProfile JWT Authentication 1.0 APIs.

Getting started

If you already know how to use Java EE, then you already know how to use KumuluzEE. It is simple and straightforward.

See the getting started wiki section to create your first light-weight standalone Java EE app in 5 minutes.

Read tutorials at our home page.

Refer to samples for more examples.

Features

Primary features:

• No need for a traditional application server. Run your app anywhere Java runs as well as in PaaS and Docker-like environments
• Allows you to develop microservices using standard Java EE technologies.
• Allows you to gradually migrate existing Java EE applications to microservices and cloud-native architecture.
• Complete control over what Java EE components and its implementations are included. Only include what you need and make your app lightweight.
• Minimal to no configuration settings up the base server. Develop like any other Java EE application
• Quick startup time, low resource consumption and stateless scalability accelerates development
• Extend your microservices with common cloud-native patterns, such as config, discovery, logging, fault tolerance, circuit-breakers, etc. KumuluzEE provides all the building blocks.

KumuluzEE provides support for various Java EE APIs and components. The goal is to support as many Java EE components as possible (contributions welcome).

Java EE components

Currently the following components are supported with more being added over time:

• Servlet 3.1 (Jetty)
• CDI 1.2 (RI Weld)
• JAX-RS 2.1. (RI Jersey)
• JSON-P 1.0 (RI JSONP)
• JSP 2.3 (Jetty Apache Jasper)
• JPA 2.1 (RI EclipseLink)
• JPA 2.1 (RI Hibernate)
• EL 3.0 (RI UEL)
• JAX-WS (RI Metro)
• JSF 2.2 (RI Mojarra)
• WebSocket 1.1 (Jetty)
• Bean Validation 1.1 (RI Hibernate validator)
• JTA 1.2 (Narayana)

Additional features

KumuluzEE provides additional features, which are described on the project Wiki, particularly:

• Configuration framework for easy and efficient configuration of microservices from various sources, such as environment variables, configuration files (yaml), properties, etc.
• TLS/SSL support for configuring TLS/SSL.

KumuluzEE also provides support for Uber JARs. With the KumuluzEE Maven plugin, you can pack and run each microservice as a single, self-contained Uber-JAR. Details are described later in this document.

KumuluzEE extensions

In addition to the standard Java EE components, KumuluzEE also comes with several extensions that complement and extend its functionality. The extensions will follow the same modular concept as the Java EE components in which you can chose if you want to use it as well as the underlying implementation of the extension. Most extensions are geared towards creating cloud-native microservices including configuration, logging, discovery, fault tolerance including circuit-breakers, metrics, security, event streaming and more. The following extensions are available with more planned soon:

• KumuluzEE Config (File and environment variables)
• KumuluzEE Config with config server (Config server etcd/Consul)
• KumuluzEE REST (For implementation of common, advanced and flexible REST API functionalities and patterns. Includes support for exposing JPA entities through REST)
• KumuluzEE Logs (For advanced microservice framework for logging)
• KumuluzEE Discovery (For dynamic service discovery (etcd or Consul). Fully compatible with Kubernetes)
• KumuluzEE Metrics (For easy collection and reporting of performance metrics)
• KumuluzEE Security (For easy integration with OAuth2/OpenID identity and access management providers)
• KumuluzEE Health (For implementing health checks and exposing microservice health information)
• KumuluzEE Fault Tolerance (For implementing fault tolerance patterns with microservices including circuit breakers and decoupling microservices)
• KumuluzEE Event Streaming (For event streaming support using Apache Kafka)
• KumuluzEE CORS (For Cross-Origin Resource Sharing (CORS) support)
• KumuluzEE Swagger (For Swagger (OpenAPI 2) support and visualization)
• KumuluzEE OpenAPI (For OpenaAPI 3 support, interface generation and visualization)

MicroProfile

KumuluzEE is Eclipse MicroProfile compliant and provides support for:

• MicroProfile 1.0
• MicroProfile 1.1
• MicroProfile 1.2

It implements the following MicroProfile APIs:

• MicroProfile Config 1.1
• MicroProfile Health 1.0
• MicroProfile Fault Tolerance 1.0
• MicroProfile Metrics 1.0
• MicroProfile JWT Authentication 1.0

Usage

KumuluzEE ships with a BOM (bill of materials) which you can use to easily add the various components you need without worrying about the versions and their compatibility as it is required that all components are the same version.

Using maven add the BOM module of the library as a dependency to your project. The ${kumuluzee.version} variables represents the most current minor version. You can see the available version on the Release Page.

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>com.kumuluz.ee</groupId>
            <artifactId>kumuluzee-bom</artifactId>
            <version>${kumuluz.version}</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

Now you can either choose any single combinations of Java EE components or use one of the common pre-built profiles that ship as part of KumuluzEE. You can chose any of the following profiles:

MicroProfile 1.0

<!-- MicroProfile 1.0 -->
<dependency>
    <groupId>com.kumuluz.ee</groupId>
    <artifactId>kumuluzee-microProfile-1.0</artifactId>
</dependency>

MicroProfile 1.1

<!-- MicroProfile 1.1 -->
<dependency>
    <groupId>com.kumuluz.ee</groupId>
    <artifactId>kumuluzee-microProfile-1.1</artifactId>
</dependency>

MicroProfile 1.2

<!-- MicroProfile 1.2 -->
<dependency>
    <groupId>com.kumuluz.ee</groupId>
    <artifactId>kumuluzee-microProfile-1.2</artifactId>
</dependency>

To choose your Java EE components with fine grain control include them as your dependencies. You can chose any of the following artifacts:

<!-- Servlet (Jetty) -->
<dependency>
    <groupId>com.kumuluz.ee</groupId>
    <artifactId>kumuluzee-servlet-jetty</artifactId>
</dependency>

<!-- WebSocket (Jetty) -->
<dependency>
    <groupId>com.kumuluz.ee</groupId>
    <artifactId>kumuluzee-websocket-jetty</artifactId>
</dependency>

<!-- JSP (Jetty Apache Jasper) -->
<dependency>
    <groupId>com.kumuluz.ee</groupId>
    <artifactId>kumuluzee-jsp-jetty</artifactId>
</dependency>

<!-- EL (UEL) -->
<dependency>
    <groupId>com.kumuluz.ee</groupId>
    <artifactId>kumuluzee-el-uel</artifactId>
</dependency>

<!-- CDI (Weld) -->
<dependency>
    <groupId>com.kumuluz.ee</groupId>
    <artifactId>kumuluzee-cdi-weld</artifactId>
</dependency>

<!-- JPA (EclipseLink) -->
<dependency>
    <groupId>com.kumuluz.ee</groupId>
    <artifactId>kumuluzee-jpa-eclipselink</artifactId>
</dependency>

<!-- or -->

<!-- JPA (Hibernate) -->
<dependency>
    <groupId>com.kumuluz.ee</groupId>
    <artifactId>kumuluzee-jpa-hibernate</artifactId>
</dependency>

<!-- JAX-RS (Jersey) -->
<dependency>
    <groupId>com.kumuluz.ee</groupId>
    <artifactId>kumuluzee-jax-rs-jersey</artifactId>
</dependency>

<!-- JAX-WS (RI Metro) -->
<dependency>
    <groupId>com.kumuluz.ee</groupId>
    <artifactId>kumuluzee-jax-ws-metro</artifactId>
</dependency>

<!-- JSF (Mojarra) -->
<dependency>
    <groupId>com.kumuluz.ee</groupId>
    <artifactId>kumuluzee-jsf-mojarra</artifactId>
</dependency>

<!-- Bean Validation (Hibernate validator) -->
<dependency>
    <groupId>com.kumuluz.ee</groupId>
    <artifactId>kumuluzee-bean-validation-hibernate-validator</artifactId>
</dependency>

<!-- JSON-P -->
<dependency>
    <groupId>com.kumuluz.ee</groupId>
    <artifactId>kumuluzee-json-p-jsonp</artifactId>
</dependency>

<!-- JTA -->
<dependency>
    <groupId>com.kumuluz.ee</groupId>
    <artifactId>kumuluzee-jta-narayana</artifactId>
</dependency>

To choose your KumuluzEE extensions include them as your dependencies. You can find the available implementations and options at their respected project pages.

Pack and run microservice as Uber JAR

KumuluzEE (since version 2.4) provides support for packing and running microservices as Uber JARs. It also includes a Maven plugin that correctly packages the microservice.

To package a Kumuluz EE microservice into an Uber JAR, you need to add the following plugin declaration into your REST module pom.xml:

<plugin>
    <groupId>com.kumuluz.ee</groupId>
    <artifactId>kumuluzee-maven-plugin</artifactId>
    <version>${kumuluz.version}</version>
    <executions>
        <execution>
            <id>package</id>
            <goals>
                <goal>repackage</goal>
            </goals>
            <configuration>
                <finalName/>
                <outputDirectory/>
                <mainClass/>
                <webappDir/>
            </configuration>
        </execution>
    </executions>
</plugin>

Parameters

• finalName

  Final name of the generated "uber" JAR.

  Default value is: ${project.build.finalName} or ${project.artifactId}-${project.version}

• outputDirectory

  Directory containing the generated JAR.

  Default value is: ${project.build.directory}

Run

Start the application using the following command:

java -jar ${project.build.finalName}.jar

Example:

java -jar my-app-1.0.0-SNAPSHOT.jar

Getting started

You can find the getting started guide on the projects wiki. You can find samples for Java EE and KumuluzEE

Building

Ensure you have JDK 8 (or newer), Maven 3.2.1 (or newer) and Git installed

java -version
mvn -version
git --version

First clone the KumuluzEE repository:

git clone https://github.com/kumuluz/KumuluzEE.git
cd KumuluzEE

To build KumuluzEE run:

mvn clean package

This will build all modules and run the testsuite.

Once completed you will find the build archives in the modules respected target folder.

Changelog

Recent changes can be viewed on Github on the Releases Page

Contribute

See the contributing docs

When submitting an issue, please follow the guidelines.

When submitting a bugfix, write a test that exposes the bug and fails before applying your fix. Submit the test alongside the fix.

When submitting a new feature, add tests that cover the feature.

License

MIT