chore: upgrade to Java SDK v4

README.md

@@ -1,57 +1,57 @@
 # featurevisor-example-java
 
-A simple Java application that uses Featurevisor Java SDK.
+A small Java application showing how to use the [Featurevisor Java SDK](https://github.com/featurevisor/featurevisor-java).
 
-Learn more about Featurevisor: https://featurevisor.com
+Learn more about Featurevisor [here](https://featurevisor.com).
 
-## Installation
+It fetches a production datafile, creates a Featurevisor instance with customer context, then evaluates a flag, a variation, feature variables, and global variables.
 
-Clone the repository, and install the dependencies:
+## GitHub Packages access
 
-## Setup `settings.xml`
-
-Create a new file at `~/.m2/settings.xml` with the following content:
+The SDK is published through GitHub Packages. Create `~/.m2/settings.xml` with credentials that have the `read:packages` scope:
 
 ```xml
-<?xml version="1.0" encoding="UTF-8"?>
-<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
-          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-          xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0
-                              http://maven.apache.org/xsd/settings-1.0.0.xsd">
-
+<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0">
   <servers>
     <server>
       <id>github</id>
       <username>YOUR_GITHUB_USERNAME</username>
       <password>YOUR_GITHUB_TOKEN</password>
     </server>
   </servers>
-
 </settings>
 ```
 
-You can generate a new GitHub token here with `read:packages` scope: https://github.com/settings/tokens
+Keep this file outside the repository.
 
-This file is meant to not be committed to the repository, as `.gitignore` is configured to ignore it.
+## Run the example
 
-## Install dependencies
-
-```
-$ mvn install
+```sh
+mvn clean compile
+mvn exec:java -Dexec.mainClass="com.example.App"
 ```
 
-## Compile
+The application evaluates `commerce_platform`, `checkout_experience`, `max_items`, `payment_methods`, `serviceEndpoints`, and `supportContact` from this datafile:
 
-```
-$ mvn clean compile
+```text
+https://featurevisor-example-cloudflare.pages.dev/production/featurevisor-sdk-v3.json
 ```
 
-## Usage
+Expected output:
 
-```
-$ mvn exec:java -Dexec.mainClass="com.example.App"
+```text
+Commerce platform enabled: true
+Checkout variation: express
+Maximum checkout items: 25
+Payment methods: [card, wallet]
+Service endpoint: https://api.eu.example.com (timeout: 1200 ms, retries: 4)
+Support contact: [email protected]
 ```
 
+Change the context in `App.java` to see how Featurevisor selects different rules, variations, and global variable overrides.
+
 ## Featurevisor project
 
-Uses this Featurevisor project to fetch the configuration from: https://github.com/featurevisor/featurevisor-example-cloudflare
+The datafile is generated by the [Featurevisor Cloudflare example](https://github.com/featurevisor/featurevisor-example-cloudflare).
+
+Learn more in the [Featurevisor Java SDK documentation](https://featurevisor.com/docs/sdks/java/).

pom.xml

@@ -16,6 +16,7 @@
     <properties>
         <maven.compiler.source>11</maven.compiler.source>
         <maven.compiler.target>11</maven.compiler.target>
+        <maven.compiler.release>11</maven.compiler.release>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     </properties>
 
@@ -31,12 +32,7 @@
         <dependency>
             <groupId>com.featurevisor</groupId>
             <artifactId>featurevisor-java</artifactId>
-            <version>3.0.0</version>
-        </dependency>
-        <dependency>
-            <groupId>com.fasterxml.jackson.core</groupId>
-            <artifactId>jackson-databind</artifactId>
-            <version>2.15.2</version>
+            <version>4.0.0</version>
         </dependency>
     </dependencies>
 
@@ -47,8 +43,7 @@
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>3.11.0</version>
                 <configuration>
-                    <source>11</source>
-                    <target>11</target>
+                    <release>11</release>
                 </configuration>
             </plugin>
             <plugin>

src/main/java/com/example/App.java

@@ -1,44 +1,86 @@
 package com.example;
 
 import com.featurevisor.sdk.Featurevisor;
+import com.featurevisor.sdk.FeaturevisorLogLevel;
 
 import java.net.URI;
 import java.net.http.HttpClient;
 import java.net.http.HttpRequest;
 import java.net.http.HttpResponse;
+import java.time.Duration;
+import java.util.List;
+import java.util.Map;
 
 public class App {
-    public static void main(String[] args) {
+    private static final String DATAFILE_URL =
+            "https://featurevisor-example-cloudflare.pages.dev/production/featurevisor-sdk-v3.json";
+
+    public static void main(String[] args) throws Exception {
+        String datafile = fetchDatafile();
+        Map<String, Object> context = Map.of(
+                "userId", "customer-123",
+                "country", "nl",
+                "locale", "nl-NL",
+                "accountPlan", "pro"
+        );
+
+        Featurevisor f = Featurevisor.createFeaturevisor(
+                new Featurevisor.FeaturevisorOptions()
+                        .datafileString(datafile)
+                        .context(context)
+                        .logLevel(FeaturevisorLogLevel.ERROR)
+        );
+
         try {
-            // Fetch JSON content from the Featurevisor datafile URL
-            String jsonContent = fetchJsonFromUrl("https://featurevisor-example-cloudflare.pages.dev/production/featurevisor-tag-all.json");
-            System.out.println("Fetched JSON content");
-
-            // Create Featurevisor SDK instance with the datafile content
-            Featurevisor instance = Featurevisor.createFeaturevisor(
-                    new Featurevisor.FeaturevisorOptions().datafileString(jsonContent));
-
-            // evaluate feature
-            boolean isFeatureEnabled = instance.isEnabled("my_feature");
-            System.out.println("Feature is enabled: " + isFeatureEnabled);
-        } catch (Exception e) {
-            System.err.println("Error: " + e.getMessage());
-            e.printStackTrace();
+            boolean commerceEnabled = f.isEnabled("commerce_platform");
+            String checkoutVariation = f.getVariation("checkout_experience");
+            Integer maxItems = f.getVariableInteger("checkout_experience", "max_items");
+            List<String> paymentMethods = f.getVariableArray(
+                    "checkout_experience",
+                    "payment_methods"
+            );
+            Map<String, Object> endpoints = f.getVariableObject("serviceEndpoints");
+            String supportContact = f.getVariableString("supportContact");
+
+            System.out.println("Commerce platform enabled: " + commerceEnabled);
+            System.out.println("Checkout variation: " + valueOrUnavailable(checkoutVariation));
+            System.out.println("Maximum checkout items: " + valueOrUnavailable(maxItems));
+            System.out.println("Payment methods: " + paymentMethods);
+            System.out.printf(
+                    "Service endpoint: %s (timeout: %s ms, retries: %s)%n",
+                    endpoints.get("baseUrl"),
+                    endpoints.get("timeoutMs"),
+                    endpoints.get("retries")
+            );
+            System.out.println("Support contact: " + valueOrUnavailable(supportContact));
+        } finally {
+            f.close();
         }
     }
 
-    private static String fetchJsonFromUrl(String url) throws Exception {
-        HttpClient client = HttpClient.newHttpClient();
+    private static String fetchDatafile() throws Exception {
+        HttpClient client = HttpClient.newBuilder()
+                .connectTimeout(Duration.ofSeconds(10))
+                .build();
         HttpRequest request = HttpRequest.newBuilder()
-                .uri(URI.create(url))
+                .uri(URI.create(DATAFILE_URL))
+                .timeout(Duration.ofSeconds(10))
+                .header("Accept", "application/json")
                 .build();
+        HttpResponse<String> response = client.send(
+                request,
+                HttpResponse.BodyHandlers.ofString()
+        );
 
-        HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
-
-        if (response.statusCode() != 200) {
-            throw new RuntimeException("Failed to fetch JSON: HTTP " + response.statusCode());
+        if (response.statusCode() < 200 || response.statusCode() >= 300) {
+            throw new IllegalStateException(
+                    "Datafile request failed with HTTP " + response.statusCode()
+            );
         }
-
         return response.body();
     }
+
+    private static Object valueOrUnavailable(Object value) {
+        return value == null ? "unavailable" : value;
+    }
 }