Update the Hello Java application based on the new specification. (#22)

The hello app should run continuously now, printing an ASCII logo when
the flag is true, and supporting the CI mode.

Also updated the code to take the SDK Key via the environment variable,
which we prefer for CI reasons.

Author: louis-launchdarkly

.circleci/config.yml

@@ -0,0 +1,35 @@
+name: Build and run
+on:
+  schedule:
+    # * is a special character in YAML so you have to quote this string
+    - cron:  '0 9 * * *'
+  push:
+    branches: [ main, 'feat/**' ]
+    paths-ignore:
+      - '**.md' # Do not need to run CI for markdown changes.
+  pull_request:
+    branches: [ main, 'feat/**' ]
+    paths-ignore:
+      - '**.md'
+
+jobs:
+  build-and-run:
+    runs-on: ubuntu-latest
+
+    permissions:
+      id-token: write # Needed if using OIDC to get release secrets.
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Java
+        uses: actions/setup-java@v4
+        with:
+          distribution: 'temurin'
+          java-version: '21'
+
+      - uses: launchdarkly/gh-actions/actions/verify-hello-app@verify-hello-app-v1.0.1
+        with:
+          use_server_key: true
+          role_arn: ${{ vars.AWS_ROLE_ARN }}
+          command: ./gradlew run

.github/workflows/ci.yml

@@ -0,0 +1,2 @@
+# Repository Maintainers
+* @launchdarkly/team-sdk-java 

CODEOWNERS

@@ -1,18 +1,20 @@
-# LaunchDarkly Sample Java Application

+# LaunchDarkly Sample Java Application
 
 We've built a simple console application that demonstrates how LaunchDarkly's SDK works.
 
-
Below, you'll find the basic build procedure, but for more comprehensive instructions, you can visit your [Quickstart page](https://app.launchdarkly.com/quickstart#/) or the [Java SDK reference guide](https://docs.launchdarkly.com/sdk/server-side/java).
+Below, you'll find the basic build procedure, but for more comprehensive instructions, you can visit your [Quickstart page](https://app.launchdarkly.com/quickstart#/) or the [Java SDK reference guide](https://docs.launchdarkly.com/sdk/server-side/java).
 
-## Build instructions

+## Build instructions
 
-This project uses [Gradle](https://gradle.org/). It requires that Java is already installed on your system (version 8 or higher). It will automatically use the latest release of the LaunchDarkly SDK with major version 6.
+This project uses [Gradle](https://gradle.org/). It requires that Java is already installed on your system (version 8 or higher). It will automatically use the latest release of the LaunchDarkly SDK with major version 7.
 
-1. Edit `src/main/java/Hello.java` and set the value of `SDK_KEY` to your LaunchDarkly SDK key. If there is an existing boolean feature flag in your LaunchDarkly project that you want to evaluate, set `FEATURE_FLAG_KEY` to the flag key.
+1. Set the value of environment variable `LAUNCHDARKLY_SERVER_KEY` to your LaunchDarkly SDK key. If there is an existing boolean feature flag in your LaunchDarkly project that you want to evaluate, edit `src/main/java/Hello.java` and set `FEATURE_FLAG_KEY` in code to the flag key.
 
-```java
-  static final String SDK_KEY = "1234567890abcdef";
+```sh
+  export LAUNCHDARKLY_SERVER_KEY=1234567890abcdef
+```
 
+```java
   static final String FEATURE_FLAG_KEY = "my-flag";
 ```
 

README.md

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.5-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.7-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

gradle/wrapper/gradle-wrapper.properties

@@ -6,24 +6,56 @@
 public class Hello {
 
   // Set SDK_KEY to your LaunchDarkly SDK key.
-  static final String SDK_KEY = "";
+  static String SDK_KEY = "";
 
   // Set FEATURE_FLAG_KEY to the feature flag key you want to evaluate.
-  static final String FEATURE_FLAG_KEY = "my-boolean-flag";
+  static String FEATURE_FLAG_KEY = "sample-feature";
 
   private static void showMessage(String s) {
     System.out.println("*** " + s);
     System.out.println();
   }
 
+  private static void showBanner() {
+    showMessage("\n        ██       \n" +
+                "          ██     \n" +
+                "      ████████   \n" +
+                "         ███████ \n" +
+                "██ LAUNCHDARKLY █\n" +
+                "         ███████ \n" +
+                "      ████████   \n" +
+                "          ██     \n" +
+                "        ██       \n");
+  }
+
   public static void main(String... args) throws Exception {
+    // Set this environment variable to skip the loop process and evaluate the flag
+    // a single time.
+    boolean CIMode = System.getenv("CI") != null;
+
+    // Get SDK Key from env variable LAUNCHDARKLY_SERVER_KEY
+    String envSDKKey = System.getenv("LAUNCHDARKLY_SERVER_KEY");
+    if(envSDKKey != null) {
+      SDK_KEY = envSDKKey;
+    }
+
+    String envFlagKey = System.getenv("LAUNCHDARKLY_FLAG_KEY");
+    if(envFlagKey != null) {
+      FEATURE_FLAG_KEY = envFlagKey;
+    }
+
     LDConfig config = new LDConfig.Builder().build();
 
+    if (SDK_KEY == null || SDK_KEY.equals("")) {
+      showMessage("Please set the LAUNCHDARKLY_SERVER_KEY environment variable or edit Hello.java to set SDK_KEY to your LaunchDarkly SDK key first.");
+      System.exit(1);
+    }
+
     final LDClient client = new LDClient(SDK_KEY, config);
     if (client.isInitialized()) {
       showMessage("SDK successfully initialized!");
     } else {
-      showMessage("SDK failed to initialize");
+      showMessage("SDK failed to initialize.  Please check your internet connection and SDK credential for any typo.");
       System.exit(1);
     }
 
@@ -37,22 +69,25 @@ public static void main(String... args) throws Exception {
     boolean flagValue = client.boolVariation(FEATURE_FLAG_KEY, context, false);
     showMessage("Feature flag '" + FEATURE_FLAG_KEY + "' is " + flagValue + " for this context");
 
-    // Here we request that the SDK flush pending analytic events so that you see
-    // data for the above evaluation on the dashboard immediatelynow rather than
-    // at the next automatic flush interval. You don't need to do this under normal
-    // circumstances in your own application.
-    client.flush();
+    if (flagValue) {
+      showBanner();
+    }
+
+    //If this is building for CI, we don't need to keep running the Hello App continously.
+    if(CIMode) {
+      System.exit(0);
+    }
 
     // We set up a flag change listener so you can see flag changes as you change
     // the flag rules.
-    client.getFlagTracker().addFlagChangeListener(event -> {
-      showMessage("Feature flag '" + event.getKey() + "' has changed.");
-      if (event.getKey().equals(FEATURE_FLAG_KEY)) {
-        boolean value = client.boolVariation(FEATURE_FLAG_KEY, context, false);
-        showMessage("Feature flag '" + FEATURE_FLAG_KEY + "' is " + value + " for this context");
-      }
+    client.getFlagTracker().addFlagValueChangeListener(FEATURE_FLAG_KEY, context, event -> {
+        showMessage("Feature flag '" + FEATURE_FLAG_KEY + "' is " + event.getNewValue() + " for this context");
+
+        if (event.getNewValue().booleanValue()) {
+          showBanner();
+        }
     });
-    showMessage("Listening for feature flag changes.  Use Ctrl+C to terminate.");
+    showMessage("Listening for feature flag changes.");
 
     // Here we ensure that when the application terminates, the SDK shuts down
     // cleanly and has a chance to deliver analytics events to LaunchDarkly.