solution

.github/workflows/ci.yml

@@ -7,10 +7,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - name: Set up JDK 17
+      - name: Set up JDK 21
         uses: actions/setup-java@v4
         with:
-          java-version: '17'
+          java-version: '21'
           distribution: 'temurin'
           cache: maven
       - name: Build with Maven

pom.xml

@@ -9,8 +9,8 @@
     <version>1.0-SNAPSHOT</version>
 
     <properties>
-        <maven.compiler.source>17</maven.compiler.source>
-        <maven.compiler.target>17</maven.compiler.target>
+        <maven.compiler.source>21</maven.compiler.source>
+        <maven.compiler.target>21</maven.compiler.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <maven.checkstyle.plugin.configLocation>
             https://raw.githubusercontent.com/mate-academy/style-guides/master/java/checkstyle.xml

src/main/java/mate/academy/AsyncRequestProcessor.java

@@ -1,16 +1,46 @@
 package mate.academy;
 
+import java.util.Map;
 import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.Executor;
 
 public class AsyncRequestProcessor {
     private final Executor executor;
+    private final Map<String, UserData> cache = new ConcurrentHashMap<>();
 
     public AsyncRequestProcessor(Executor executor) {
         this.executor = executor;
     }
 
     public CompletableFuture<UserData> processRequest(String userId) {
-        return null;
+        UserData cached = cache.get(userId);
+        if (cached != null) {
+            return CompletableFuture.completedFuture(cached);
+        }
+
+        return fetchUserDataAsync(userId)
+                .thenApply(userData -> saveToCache(userId, userData));
+    }
+
+    private CompletableFuture<UserData> fetchUserDataAsync(String userId) {
+        return CompletableFuture.supplyAsync(() -> {
+            simulateDatabaseCall();
+            return new UserData(userId, "Details for " + userId);
+        }, this.executor);
+    }
+
+    private UserData saveToCache(String userId, UserData userData) {
+        cache.put(userId, userData);
+        return userData;
+    }
+
+    private void simulateDatabaseCall() {
+        try {
+            Thread.sleep(1000);
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+            throw new RuntimeException("Data fetching interrupted", e);
+        }
     }
 }

src/main/java/mate/academy/Main.java

@@ -2,11 +2,13 @@
 
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 
 public class Main {
     public static void main(String[] args) {
         // Feel free to play with AsyncRequestProcessor in this main method if you want
-        ExecutorService executor = null; // Provide implementation that fits your needs
+        ExecutorService executor = Executors.newFixedThreadPool(10); // Provide implementation
+        // that fits your needs
         AsyncRequestProcessor asyncRequestProcessor = new AsyncRequestProcessor(executor);
 
         // Simulating multiple concurrent requests