fix: use Qualifier to force bean dependency

packages/java/endpoint/src/main/java/com/vaadin/hilla/EndpointControllerConfiguration.java

@@ -155,7 +155,7 @@ private static ObjectMapper createDefaultEndpointMapper(
      */
     @Bean
     EndpointInvoker endpointInvoker(ApplicationContext applicationContext,
-            ObjectMapper hillaEndpointObjectMapper,
+            @Qualifier("hillaEndpointObjectMapper") ObjectMapper hillaEndpointObjectMapper,
             ExplicitNullableTypeChecker explicitNullableTypeChecker,
             ServletContext servletContext, EndpointRegistry endpointRegistry) {
         return new EndpointInvoker(applicationContext,

packages/java/endpoint/src/main/java/com/vaadin/hilla/signals/config/SignalsConfiguration.java

@@ -23,6 +23,7 @@
 import com.vaadin.hilla.signals.core.registry.SecureSignalsRegistry;
 import com.vaadin.hilla.signals.handler.SignalsHandler;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 
@@ -37,7 +38,7 @@ public class SignalsConfiguration {
     private final EndpointInvoker endpointInvoker;
 
     public SignalsConfiguration(EndpointInvoker endpointInvoker,
-            ObjectMapper hillaEndpointObjectMapper) {
+            @Qualifier("hillaEndpointObjectMapper") ObjectMapper hillaEndpointObjectMapper) {
         this.endpointInvoker = endpointInvoker;
         Signal.setMapper(hillaEndpointObjectMapper);
     }

packages/java/endpoint/src/test/java/com/vaadin/hilla/EndpointControllerConfigurationTest.java

@@ -6,6 +6,7 @@
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.jackson.JacksonProperties;
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringRunner;
@@ -25,9 +26,32 @@ public class EndpointControllerConfigurationTest {
     @Autowired
     private EndpointAccessChecker endpointAccessChecker;
 
+    @Autowired
+    private ConfigurableApplicationContext context;
+
     @Test
     public void dependenciesAvailable() {
         Assert.assertNotNull(endpointRegistry);
         Assert.assertNotNull(endpointAccessChecker);
     }
+
+    @Test
+    public void testEndpointInvokerUsesQualifiedObjectMapper()
+            throws NoSuchFieldException, IllegalAccessException {
+        var endpointInvoker = context.getBean(EndpointInvoker.class);
+        var objectMapper = context.getBean("hillaEndpointObjectMapper");
+
+        Assert.assertNotNull("EndpointInvoker should not be null",
+                endpointInvoker);
+        Assert.assertNotNull("hillaEndpointObjectMapper should not be null",
+                objectMapper);
+
+        var field = EndpointInvoker.class
+                .getDeclaredField("endpointObjectMapper");
+        field.setAccessible(true);
+
+        Assert.assertSame(
+                "EndpointInvoker should use the qualified hillaEndpointObjectMapper",
+                objectMapper, field.get(endpointInvoker));
+    }
 }