Ensure that user provided ObjectMapperCustomizer objects always have higher priority

Fixes: #7116

extensions/jackson/deployment/src/main/java/io/quarkus/jackson/deployment/JacksonProcessor.java

@@ -232,6 +232,11 @@ public class JacksonProcessor {
 
                 customize.returnValue(null);
             }
+
+            // ensure that the things we auto-register have the lower priority - this ensures that user registered modules take priority
+            try (MethodCreator priority = classCreator.getMethodCreator("priority", int.class)) {
+                priority.returnValue(priority.load(ObjectMapperCustomizer.MINIMUM_PRIORITY));
+            }
         }
     }
 }

extensions/jackson/runtime/src/main/java/io/quarkus/jackson/ObjectMapperCustomizer.java

@@ -10,7 +10,22 @@ import com.fasterxml.jackson.databind.ObjectMapper;
  * <p>
  * See also {@link ObjectMapperProducer#objectMapper}.
  */
-public interface ObjectMapperCustomizer {
+public interface ObjectMapperCustomizer extends Comparable<ObjectMapperCustomizer> {
+
+    int MINIMUM_PRIORITY = Integer.MIN_VALUE;
+    int DEFAULT_PRIORITY = 0;
 
     void customize(ObjectMapper objectMapper);
+
+    /**
+     * Defines the priority that the customizers are applied.
+     * A lower integer value means that the customizer will be applied after a customizer with a higher priority
+     */
+    default int priority() {
+        return DEFAULT_PRIORITY;
+    }
+
+    default int compareTo(ObjectMapperCustomizer o) {
+        return Integer.compare(o.priority(), priority());
+    }
 }

extensions/jackson/runtime/src/main/java/io/quarkus/jackson/ObjectMapperProducer.java

@@ -1,5 +1,9 @@
 package io.quarkus.jackson;
 
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
 import javax.enterprise.context.ApplicationScoped;
 import javax.enterprise.inject.Instance;
 import javax.enterprise.inject.Produces;
@@ -17,9 +21,20 @@ public class ObjectMapperProducer {
     @Produces
     public ObjectMapper objectMapper(Instance<ObjectMapperCustomizer> customizers) {
         ObjectMapper objectMapper = new ObjectMapper();
-        for (ObjectMapperCustomizer customizer : customizers) {
+        List<ObjectMapperCustomizer> sortedCustomizers = sortCustomizersInDescendingPriorityOrder(customizers);
+        for (ObjectMapperCustomizer customizer : sortedCustomizers) {
             customizer.customize(objectMapper);
         }
         return objectMapper;
     }
+
+    private List<ObjectMapperCustomizer> sortCustomizersInDescendingPriorityOrder(
+            Instance<ObjectMapperCustomizer> customizers) {
+        List<ObjectMapperCustomizer> sortedCustomizers = new ArrayList<>();
+        for (ObjectMapperCustomizer customizer : customizers) {
+            sortedCustomizers.add(customizer);
+        }
+        Collections.sort(sortedCustomizers);
+        return sortedCustomizers;
+    }
 }

extensions/resteasy-jackson/deployment/pom.xml

@@ -26,6 +26,16 @@
             <groupId>io.quarkus</groupId>
             <artifactId>quarkus-resteasy-jackson</artifactId>
         </dependency>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-junit5-internal</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>io.rest-assured</groupId>
+            <artifactId>rest-assured</artifactId>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>

extensions/resteasy-jackson/deployment/src/test/java/io/quarkus/resteasy/jackson/DateDto.java

@@ -0,0 +1,22 @@
+package io.quarkus.resteasy.jackson;
+
+import java.time.ZonedDateTime;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+public class DateDto {
+    @JsonProperty("current_date")
+    private ZonedDateTime currentDate;
+
+    public void setCurrentDate(ZonedDateTime currentDate) {
+        this.currentDate = currentDate;
+    }
+
+    public ZonedDateTime getCurrentDate() {
+        return currentDate;
+    }
+
+    public DateDto(ZonedDateTime currentDate) {
+        this.currentDate = currentDate;
+    }
+}

extensions/resteasy-jackson/deployment/src/test/java/io/quarkus/resteasy/jackson/HelloResource.java

@@ -0,0 +1,18 @@
+package io.quarkus.resteasy.jackson;
+
+import java.time.ZonedDateTime;
+
+import javax.ws.rs.GET;
+import javax.ws.rs.Path;
+import javax.ws.rs.Produces;
+import javax.ws.rs.core.MediaType;
+
+@Produces(MediaType.APPLICATION_JSON)
+@Path("/hello")
+public class HelloResource {
+
+    @GET
+    public DateDto hello() {
+        return new DateDto(ZonedDateTime.now());
+    }
+}

extensions/resteasy-jackson/deployment/src/test/java/io/quarkus/resteasy/jackson/MultipleTimeModuleTest.java

@@ -0,0 +1,47 @@
+package io.quarkus.resteasy.jackson;
+
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.not;
+
+import org.jboss.shrinkwrap.api.ShrinkWrap;
+import org.jboss.shrinkwrap.api.spec.JavaArchive;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import io.quarkus.test.QuarkusDevModeTest;
+import io.restassured.RestAssured;
+
+// this test really belongs in the jackson module, but it's been added here to avoid test classpath issues
+public class MultipleTimeModuleTest {
+
+    @RegisterExtension
+    static QuarkusDevModeTest TEST = new QuarkusDevModeTest()
+            .setArchiveProducer(() -> ShrinkWrap.create(JavaArchive.class)
+                    .addClasses(TimeCustomizer.class, DateDto.class, HelloResource.class));
+
+    @Test
+    public void testDateIsAlwaysInTheExpectedFormat() {
+        verifyExpectedResult();
+
+        modifyResource();
+        verifyExpectedResult();
+
+        modifyResource();
+        verifyExpectedResult();
+
+        modifyResource();
+        verifyExpectedResult();
+    }
+
+    private void verifyExpectedResult() {
+        RestAssured.get("/hello").then()
+                .statusCode(200)
+                .body(containsString("Z"), not(containsString("+")));
+    }
+
+    private void modifyResource() {
+        TEST.modifySourceFile("TimeCustomizer.java", s -> s.replace("hello",
+                "hello2"));
+    }
+
+}

extensions/resteasy-jackson/deployment/src/test/java/io/quarkus/resteasy/jackson/TimeCustomizer.java

@@ -0,0 +1,27 @@
+package io.quarkus.resteasy.jackson;
+
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatterBuilder;
+
+import javax.inject.Singleton;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
+import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
+import com.fasterxml.jackson.datatype.jsr310.ser.ZonedDateTimeSerializer;
+
+import io.quarkus.jackson.ObjectMapperCustomizer;
+
+@Singleton
+public class TimeCustomizer implements ObjectMapperCustomizer {
+
+    @Override
+    public void customize(ObjectMapper objectMapper) {
+        JavaTimeModule customDateModule = new JavaTimeModule();
+        customDateModule.addSerializer(ZonedDateTime.class, new ZonedDateTimeSerializer(
+                new DateTimeFormatterBuilder().appendInstant(0).toFormatter().withZone(ZoneId.of("Z"))));
+        objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS)
+                .registerModule(customDateModule);
+    }
+}