Flagship4j

Flagship4j is a Java library that provides multiple API client SDKs to integrate with toggle systems (for now, we support Openflagr) and follows the Open-Feature specification. There are different libraries for different use-cases, e.g. flagship4j-openfeature-javaflagr-starter for pure Java application, flagship4j-openfeature-spring-boot-starter for a Spring Boot application.

The libraries are listed below:

Libraries

Name	Description
flagship4j-javaflagr-core	Native OpenFlagr SDK for Java
flagship4j-openfeature-provider-javaflagr	OpenFlagr Provider for OpenFeature
flagship4j-openfeature-javaflagr-starter	A convenient dependency descriptors for using OpenFeature SDK with OpenFlagr SDK
flagship4j-javaflagr-spring-boot-web-starter	(Deprecated) OpenFlagr implementation for Spring Boot Web Starter
flagship4j-openfeature-spring-boot-starter	Auto configuration with OpenFeature and OpenFlagr SDK for Spring Boot Starter

Prerequisites

Java 8 or later if you are a user.

Getting started

There are many libraries we provide. Among them, we mostly recommend to use the flagship4j-openfeature-spring-boot-starter. For other libraries and use cases, please refer to the Examples and Libraries

Use feature toggle via OpenFeature interface

maven

<dependency>
  <groupId>com.linecorp.flagship4j</groupId>
  <artifactId>flagship4j-openfeature-spring-boot-starter</artifactId>
  <version>${version}</version>
</dependency>

gradle

dependencies {
    implementation "org.springframework.boot:spring-boot-starter"
    implementation "com.linecorp.flagship4j:flagship4j-openfeature-spring-boot-starter"
}

Config

please refer to Configuration options

flagship4j:
  toggle:
    flagr:
      baseUrl: http://localhost:18000
      connectionTimeout: 30
      readTimeout: 30
      callTimeout: 30
      writeTimeout: 30

Code

    private final Client client; // dependency injected by spring 
            
    ... other code
            
    ... someMethod(...) {
            Boolean isHelloWorldEnabled = client.getBooleanValue("hello-world-enabled", false);
            if (isHelloWorldEnabled) {
            System.out.println("Hello World");
        }   
    }

Install to local Maven repository

If you are developing flagship4j for your other application in local
Perform following command to deploy to local maven repository (~/.m2/repository)

./gradlew clean build publishToMavenLocal

Configuration options

Name	Description	Required
`endpoint`	The URL of the OpenFlagr evaluator.	Yes
`connectionTimeout`	A time period for establish a connection to the OpenFlagr host	Yes
`readTimeout`	The maximum time of inactivity between two data packets when waiting for the OpenFlagr host response	Yes
`writeTimeout`	The maximum time of inactivity between two data packets when sending the request to the OpenFlagr host	Yes
`callTimeout`	The time limit for a complete HTTP call to the OpenFlagr host	Yes

Examples

Name	Description
On / Off	An simple example of OpenFeature with OpenFlagr provider
A/B Testing	An A/B testing example of OpenFeature with OpenFlagr provider
Canary Release	A canary release example of OpenFeature with OpenFlagr provider
White List	A white list example of OpenFeature with OpenFlagr provider

Contributing

If you believe you found a vulnerability or you have an issue related to security, please DO NOT open a public issue. Instead, send us an email at dl_oss_dev@linecorp.com.

Before contributing to this project, please read the CONTRIBUTING.

line/Flagship4j