trial to reproduce with supplyAsync and get()

dsmf · Jan 8, 2024 · f1f2bd1 · f1f2bd1
1 parent 56e28ab
commit f1f2bd1
Show file tree

Hide file tree

Showing 2 changed files with 26 additions and 0 deletions.
diff --git a/server/src/main/java/com/foo/server/ProcessController.java b/server/src/main/java/com/foo/server/ProcessController.java
@@ -9,6 +9,7 @@
 import org.springframework.web.bind.annotation.RestController;
 
 import java.util.List;
+import java.util.concurrent.ExecutionException;
 import java.util.stream.IntStream;
 
 @RestController
@@ -22,6 +23,20 @@ public ProcessController(final ProcessorService processorService) {
         this.processorService = processorService;
     }
 
+    @GetMapping("/hello2")
+    public String helloAsyncInService() {
+        final List<Person> persons = getPeople();
+        try {
+            // with this construct I get the NullPointerException: Cannot invoke "org.jxls.expression.ExpressionEvaluatorFactory.createExpressionEvaluator(String)"
+            // in the completable future
+            return processorService.processSupplyAsync(persons).get();
+        } catch (InterruptedException e) {
+            throw new RuntimeException(e);
+        } catch (ExecutionException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
     @GetMapping("/hello-async")
     public ResponseEntity<String> helloAsync() {
         final List<Person> persons = getPeople();

diff --git a/server/src/main/java/com/foo/server/ProcessorService.java b/server/src/main/java/com/foo/server/ProcessorService.java
@@ -8,6 +8,7 @@
 import org.springframework.stereotype.Service;
 
 import java.util.List;
+import java.util.concurrent.CompletableFuture;
 
 @Service
 public class ProcessorService {
@@ -17,6 +18,16 @@ public class ProcessorService {
     public ProcessorService() {
     }
 
+    public CompletableFuture<String> processSupplyAsync(List<Person> persons) {
+        return CompletableFuture.supplyAsync(() -> {
+            LOG.debug("processSupplyAsync -- start");
+            final String result = process(persons);
+            LOG.info("result: {}", result);
+            LOG.debug("processSupplyAsync -- end");
+            return result;
+        });
+    }
+
     @Async
     public void processAsync(List<Person> persons) {
         LOG.debug("processAsync -- start");