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	Default value
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.