jdk17 support

common/src/main/java/stirling/software/common/service/JobExecutorService.java

@@ -5,7 +5,6 @@ import java.util.Map;
 import java.util.UUID;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
 import java.util.function.Supplier;
@@ -24,6 +23,7 @@ import lombok.extern.slf4j.Slf4j;
 import stirling.software.common.controller.WebSocketProgressController;
 import stirling.software.common.model.job.JobProgress;
 import stirling.software.common.model.job.JobResponse;
+import stirling.software.common.util.ExecutorFactory;
 
 /** Service for executing jobs asynchronously or synchronously */
 @Service
@@ -36,7 +36,7 @@ public class JobExecutorService {
     private final HttpServletRequest request;
     private final ResourceMonitor resourceMonitor;
     private final JobQueue jobQueue;
-    private final ExecutorService executor = Executors.newVirtualThreadPerTaskExecutor();
+    private final ExecutorService executor = ExecutorFactory.newVirtualOrCachedThreadExecutor();
     private final long effectiveTimeoutMs;
 
     public JobExecutorService(

common/src/main/java/stirling/software/common/service/JobQueue.java

@@ -19,6 +19,7 @@ import lombok.extern.slf4j.Slf4j;
 
 import stirling.software.common.controller.WebSocketProgressController;
 import stirling.software.common.model.job.JobProgress;
+import stirling.software.common.util.ExecutorFactory;
 
 /**
  * Manages a queue of jobs with dynamic sizing based on system resources. Used when system resources
@@ -46,18 +47,8 @@ public class JobQueue {
     private BlockingQueue<QueuedJob> jobQueue;
     private final Map<String, QueuedJob> jobMap = new ConcurrentHashMap<>();
     private final ScheduledExecutorService scheduler = Executors.newSingleThreadScheduledExecutor();
-    private final ExecutorService jobExecutor;
+    private final ExecutorService jobExecutor = ExecutorFactory.newVirtualOrCachedThreadExecutor();
-    
+
-    // Initialize executor based on Java version
-    {
-        ExecutorService executor;
-        try {
-            executor = Executors.newVirtualThreadPerTaskExecutor();
-        } catch (NoSuchMethodError e) {
-            executor = Executors.newCachedThreadPool();
-        }
-        jobExecutor = executor;
-    }
     private boolean shuttingDown = false;
 
     @Getter private int rejectedJobs = 0;

common/src/main/java/stirling/software/common/util/ExecutorFactory.java

@@ -0,0 +1,31 @@
+package stirling.software.common.util;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class ExecutorFactory {
+
+    /**
+     * Creates an ExecutorService using virtual threads if available (Java 21+), or falls back to a
+     * cached thread pool on older Java versions.
+     */
+    public static ExecutorService newVirtualOrCachedThreadExecutor() {
+        try {
+            ExecutorService executor =
+                    (ExecutorService)
+                            Executors.class
+                                    .getMethod("newVirtualThreadPerTaskExecutor")
+                                    .invoke(null);
+            return executor;
+        } catch (NoSuchMethodException e) {
+            log.debug("Virtual threads not available; falling back to cached thread pool.");
+        } catch (Exception e) {
+            log.debug("Error initializing virtual thread executor: {}", e.getMessage(), e);
+        }
+
+        return Executors.newCachedThreadPool();
+    }
+}