add support for JsonValue annotations

When constructing a JacksonBasedProperty, the nestedContainer is checked if any property has a JsonValue annotation. If such property exists, the typeInformation and the embeddedContainer are passed directly to the property with the JsonValue annotation (skipping the current property).

contentgrid-spring-data-rest/src/main/java/com/contentgrid/spring/data/rest/mapping/jackson/JacksonBasedProperty.java

@@ -5,15 +5,38 @@
 import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonProperty.Access;
+import com.fasterxml.jackson.annotation.JsonValue;
 import java.lang.annotation.Annotation;
+import java.util.ArrayList;
 import java.util.Optional;
 import java.util.function.Predicate;
-import lombok.RequiredArgsConstructor;
 import org.springframework.data.util.TypeInformation;
 
-@RequiredArgsConstructor
 public class JacksonBasedProperty implements Property {
     private final Property delegate;
+    private final JacksonBasedProperty value;
+
+    public JacksonBasedProperty(Property delegate) {
+        this.delegate = delegate;
+        this.value = findJsonValue().orElse(null);
+    }
+
+    protected Optional<JacksonBasedProperty> findJsonValue() {
+        var values = new ArrayList<Property>();
+        delegate.nestedContainer()
+                .ifPresent(container -> {
+                    container.doWithProperties(property -> {
+                        var jsonValue = property.findAnnotation(JsonValue.class)
+                                .map(JsonValue::value)
+                                .orElse(false);
+                        if (jsonValue) {
+                            values.add(property);
+                        }
+                    });
+                });
+        return values.stream().findFirst()
+                .map(JacksonBasedProperty::new);
+    }
 
     protected Optional<String> preferredName() {
         return delegate.findAnnotation(JsonProperty.class)
@@ -28,6 +51,9 @@ public String getName() {
 
     @Override
     public TypeInformation<?> getTypeInformation() {
+        if (value != null) {
+            return value.getTypeInformation();
+        }
         return delegate.getTypeInformation();
     }
 
@@ -55,6 +81,9 @@ public boolean isReadOnly() {
 
     @Override
     public Optional<Container> nestedContainer() {
+        if (value != null) {
+            return value.nestedContainer();
+        }
         return delegate.nestedContainer()
                 .map(JacksonBasedContainer::new);
     }